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This is to certify that the

thesis entitled

THE TECTONIC EVOLUTION
OF KAMCHATKA PENINSULA, USSR
presented by

Bruce F . Watson

has been accepted towards fulfillment
of the requirements for

M.S. degree in Geological Sciences

 

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a” Major flessor

Kaz F 'it
July 11, 1985 ”ya “J a

 

MSU is an Affirmative Action/Equal Opportunity Institution

 

 

 

 

 

 

 

 

)V1ESI_J RETURNING MATERIALS:
Place in book drop to
LJBRARJES remove this checkout from
w. your record. FINES will

 

 

 

be charged if book is
returned after the date
stamped below.

 

 

 

THE TECTONIC EVOLUTION
OF KAMCHATKA PENINSULA, USSR

By

Bruce F. Watson

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Geological Sciences

1985

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ABSTRACT

THE TECTONIC EVOLUTION
OF KAMCHATKA PENINSULA, USSR

By

Bruce F. Watson

Kamchatka Peninsula is composed of ten tectonostrati-
graphic suspect terranes of oceanic origin which developed
during Mesozoic and Cenozoic time. Seven of the terranes
consist of an oceanic crustal layer overlain by volcanic
arc and sedimentary facies (Kvakhon, Omgon, Sredinny Range,
Eastern Ranges, Central Kamchatka Basin, Cape Kamchatka and
Southern Kamchatka) while the other three terranes are
represented by different facies. The Malkinsk terrane
consists of granites and pelitic schists and is probably a
metamorphic fragment of a volcanic arc. The Ganal terrane
consists of mafic schists, the parent rocks of which were
oceanic basalts. The Kronotsky terrane consists of a
basaltic sequence of rocks similar in many respects to high
alumina island arc basalts. The terranes of Kamchatka are
stitched together by several Mesozoic and Cenozoic volcanic
arcs while tectonic activity has been controlled by the
directions of motion of the Farallon, Izanagi, Kula and

Pacific plates.

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ACKNOWLEDGEMENTS

I would like to thank Dr. Kazuya Fujita, the Chairman
of my thesis committee, for encouragement and guidance
throughout the duration of my endeavor.

Thanks also to Dr. Tom Vogel and Dr. Bill Cambray for
useful comments and criticisms during the preparation of
the manuscript.

I thank Dr. David C. Engebretson for relative motion
calculations and Dr. Kensaku Tamaki for data prior to
publication.

I would also like to thank my parents, brothers and
sisters who were behind me all the way, and fellow students
and colleagues, Dave, Gary, Don, Jody, Cindy, Tim, Soo-
Meen, Jim, Jeff, Jean and Rebecca for their helpful
discussions, suggestions and friendship.

This research was supported, in part, by NSF grant
EAR 80-25267 and a teaching assistantship from Michigan

State University.

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TABLE OF CONTENTS

PAGE NO.

List of Figures ..................................... iv
List of Tables ............ . ......................... vii
Introduction........ ..... ..... ....... ......... ...... 1
Geographic Overview...... ..... ... ................... 6
Methodology........ ....... .............. ............ 13
Sources of Uncertainty... ..... . ....... .... ........ .. 15
Terrane Analysis.................................... 24
Kvakhon Terrane .................................... . 36
Omgon Terrane. ............... . ........... . ....... ... 48
Sredinny Range Terrane.............................. 6O
Malkinsk Terrane.......... .......................... 69
Central Kamchatka Basin Terrane ..... . ............... 88
Eastern Ranges Terrane ......................... ..... 96
Ganal Terrane........... ....... ..................... 110
Southern Kamchatka Terrane ............ .... .......... 119
Cape Kamchatka Terrane ...... ..... ................... 126
Kronotsky Terrane................................... 134
Eastern Kamchatka Basin............................. 142
Geologic Relations of Kamchatka With the

Kuril and Aleutian Arcs and Features of the

Sea of Okhotsk.................................... 151
Plate Motions... ...... .............................. 155
Tectonic Evolution of Kamchatka Peninsula ........... 168
Conclusions....... ......... . ............ . ........... 192
References.......... ...... .................. ..... ... 194

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LIST OF FIGURES

Figure 1. Regional map of northwest Pacific Ocean... 4
Figure 2. Geographic map of Kamchatka Peninsula .....
Figure 3. Tectonic features of the Sea of Okhotsk... 12
Figure 4. Quaternary geology map of Kamchatka

Peninsula ................................. 18
Figure 5a. General geological map of Kamchatka

Peninsula ......... . ....................... 21
Figure 5b. Geological nomenclature .................. 23
Figure 6. Terrane map ............................... 27

Figure 7. Geologic symbols for the stratigraphic

columns.... .............. . ................ 31
Figure 8a. Estimated locations of important

formations ................................ 33
Figure 8b. List of formations ........................ 35
Figure 9. Stratigraphy of the Kvakhon terrane ....... 38
Figure 10. Cross-section of the Kvakhon and

Malkinsk terranes.... ..... ...... .......... 41
Figure 11. Stratigraphy of the Omgon terrane ......... 50
Figure 12. Structural features of the Omgon terrane.. 52
Figure 13. Stratigraphy of the Sredinny Range

terrane ................................... 62
Figure 14. Stratigraphy of the Malkinsk terrane ...... 71
Figure 15. Potassium - argon radiometric dates

from Kamchatka Peninsula .................. 78
Figure 16. Age estimate of metamorphism of the

Malkinsk terrane based on argon
retention potential of various minerals... 83

Figure 17. Stratigraphy of the Central Kamchatka

Basin terrane ............................. 90
Figure 18. Magnetic anomaly map of Kamchatka
Peninsula .................. . .............. 93

iv

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24.
25.

26.

27.

28.

29.

Figure 30.

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31.

Figure 32.

LIST OF FIGURES Continued

Stratigraphy of the Eastern

Ranges terrane ............. . .............. 98
Cross-section of eastern Kamchatka ........ 107
Stratigraphy of the Ganal terrane. ........ 112

Stratigraphy of the Southern Kamchatka
terrane........... .............. . ......... 121

Stratigraphy of the Cape Kamchatka
terrane.......................... ......... 128

Stratigraphy of the Kronotsky terrane ..... 136

Stratigraphy of the Eastern
Kamchatka Basin ........................... 144

Gravity anomaly map of Kamchatka
Peninsula ................... . ............. 148

Tectonic/geologic summary of the
terranes of Kamchatka Peninsula ........... 150

Plate motion data of the Farallon,
Izanagi, Kula and Pacific plates .......... 157

Late Jurassic to Late Cretaceous
tectonic evolution of Kamchatka

Peninsula ................................. 171
a. Late Jurassic to Early Cretaceous ..... 171
b. Hauterivian to Aptian ................. 171
c. Albian.. ................. . ..... . ...... 171
d. Cenomanian ............................ 171

Santonian to Maastrichtian tectonic
evolution of Kamchatka Peninsula .......... 177

Early Paleocene tectonic
evolution of Kamchatka Peninsula .......... 180

Paleocene to Eocene tectonic
evolution of Kamchatka Peninsula .......... 183

a. Subduction of the Kula/Pacific ridge.. 183

LIST OF FIGURES Continued

b. Transcurrent motion between the

Pacific plate and Kamchatka ........... 185
Figure 33. Oligocene to Miocene tectonic evolution
of Kamchatka Peninsula .................... 188
Figure 34. Pliocene to recent tectonic evolution
of Kamchatka Peninsula .................... 191

vi

LIST OF TABLES

Table 1. General characteristics of the terranes
of Kamchatka Peninsula..... ............... 29

Table 2. Potassium/argon radiometric age
dates from the Kolpakova series of
the Malkinsk terrane ...................... 81

Table 3. Potassium/argon radiometric age dates
from the Canal terrane.... ................ 115

Table 4. Correlations between tectonic events

of Kamchatka Peninsula and relative
motions of oceanic plates ................. 160

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INTRODUCTION

Recent studies have demonstrated that large portions of
the Circum-Pacific region, including Japan, Northeast
Siberia and western North America, are composed of
accretionary tectonostratigraphic terranes (e.g., Coney et
al., 1980; Csetjey et al., 1982; Fujita and Newberry, 1983;
Taira et al., 1983; Jones et al., 1982: McWilliams and
Howell, 1982; and many others). Utilizing, the concepts of
terrane analysis (Jones et al., 1983; Schermer et al.,
1984) these studies delineate individual terranes of a
region by the examination of a wide range of information.
Geological data concerning paleontology, stratigraphy,
lithology and structural geology combined with geophysical
data derived from magnetic, gravity and seismic surveys,
are used to delineate and to outline the geologic history
of each terrane.

Directly related to the events that determined the
current configuration of the Circum—Pacific terranes are
vectoral directions of motion and velocity of oceanic
crustal plates that exist or once existed in the Pacific
Basin. Recent models concerning these motions (esp.
Engebretson, 1982) are being related to periods of
orogenesis including volcanic arc activity and quiescence,
extensional rifting, emplacement of allochthonous crustal
fragments onto continental margins, etc. (Wallace and

Engebretson, 1984; Engebretson et al., 1984; Henderson et

2
al., 1984; Page and Engebretson, 1984; and others).
Finally, combining the information about the geologic
histories of each terrane with the plate motion vector data
allows for the determination of a tentative geologic model
that describes the plate tectonic evolution of the region
of interest.

Kamchatka Peninsula, located in the northwest Pacific
Ocean (fig. 1) is a part of the Circum—Pacific region that
has not yet been interpreted in the terms of accretionary
tectonics. Kamchatka is part of northeast Siberia and has
been examined in detail by Soviet geologists who have
described volcanic arc, oceanic and continental facies
within the boundaries of the peninsula. The rocks are
predominantly of Cretaceous and Tertiary age, although
Jurassic, and possibly Devonian, assemblages may be present
(figs. 5a and 5b). The origins of the various rock types
are commonly explained in the terms of the formation and
development of geosynclinal regimes (e.g., Avdeiko, 1971;
Cnibidenko et al., 1974; Shapiro, 1981).

Preliminary examination of the geological and
geophysical data concerning Kamchatka Peninsula reveals
several different geological provinces, each of which
represents a suspect tectonostratigraphic terrane. It is
the purpose of this thesis to examine in detail the
available data on Kamchatka Peninsula in order to determine
the character and extent of the suspect terranes and to

develop a plate tectonic model outlining the tectonic

 

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evolution of Kamchatka Peninsula. The methodology used in
the analysis is outlined in a following section.

The study of Kamchatka Peninsula is important for two
primary reasons. First, because of the structural position
of the peninsula, an understanding of how Kamchatka deve-
loped through time is important for constraining models for
the tectonic development of nearby areas. These areas
include in particular, the Kuril and Aleutian arcs, the Sea
of Okhotsk and northeastern Siberia. Secondly, determin-
ation of the sequence of plate tectonic events will provide
constraints for motions of oceanic crustal plates in the

northwestern Pacific Basin.

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GEOGRAPHIC OVERVIEW

Kamchatka Peninsula is dominated by two major mountain
ranges. The Sredinny (Central) Range extends through the
center of the peninsula, from the Malkinsk block in the
south to the Koryak Highlands in the north (fig. 2). A
wide variety of rock types are exposed along the length of
the Sredinny Range. The Malkinsk and Kozyrevsk Ranges are
often included as part of the Sredinny Range (fig. 2).

The Malkinsk Range is predominantly a metamorphic terrain
of silicic rocks with large exposures of granitic
batholiths. The Kozyrevsk Range consists of mafic and
intermediate igneous rocks of oceanic and volcanic arc
origin. The majority of the Sredinny Range north of the
Kozyrevsk Range consists of exposures of young volcanic and
sedimentary rocks. Rocks similar to those found in the
Kozyrevsk Range are exposed in the Sredinny Range in the
neck of Kamchatka. Many volcanoes are found in the central
and northern regions with maximum altitude reaching 4570
meters.

The Eastern Ranges lie in the eastern portion of the
peninsula (fig. 2) and can be subdivided, from south to
north, into the Canal, Valaginsk, Tumrok and Kumroch
Ranges. Rock types exposed along the length of the ranges,
except for the Canal Range, are very similar and consist of
volcanic and sedimentary facies. The Ganal Range is a
metamorphic terrain of mafic rocks.

Between the Sredinny Range and the Eastern Ranges lies

6

 

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the Central Kamchatka Basin, a relatively flat area that is
filled in with young alluvial and fluvial sediments. The
largest volcanoes of Kamchatka are found in the central
area of this basin. Mount Klyuchevsk reaches a height of
4750 meters and is currently active.

The West Kamchatka lowlands lie between the Sredinny
Range and the Sea of Okhotsk (fig. 2). The lowlands extend
along the entire western coast of Kamchatka to a northerly
latitude of 60 degrees north. Young marine and alluvial
sedimentary rocks are common. Most of the river drainage
from the Sredinny Range flows west across the lowlands and
into the Sea of Okhotsk.

Finally, the South Bystrinsk Range is located on the
eastern coast of the southern tip of Kamchatka (fig. 2).
The range is geologically and morphological distinct from
the Eastern Ranges and is therefore not included as part of
them. The rock types exposed are identical to what is
found in the central and northern regions of the Sredinny
Range. Because of the facies similarities, the South
Bystrinsk Range is sometimes included as the southerly
continuation of the Sredinny Range.

Several geographic features in the vicinity of the
northwestern Pacific Basin and northeastern Siberia are
directly or indirectly related to Kamchatka Peninsula. Two
currently active island arcs, the Aleutian and the Kuril,
are located to the east and south of Kamchatka,

respectively (figs. 2 and 3). The Aleutian arc separates

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the Bering Sea from the Pacific Ocean and extends from the
Alaska Peninsula to Cape Kamchatka. The eastern two-thirds
of the arc is presently underthrust by the Pacific plate
while transcurrent motion with oblique underthrusting
occurs along the western one-third of the arc (Cormier,
1975; Newberry, 1983). The Kuril arc extends from north of
Hokkaido Island onto the southeastern margin of Kamchatka
Peninsula and is currently being underthrust by the Pacific
plate. The northern extent of the arc on Kamchatka
correlates with the junction of the Aleutian arc and Cape
Kamchatka, i.e., at the Kuril-Kamchatka trench junction.

To the north of Kamchatka lies the Koryak Highlands of
northeastern Siberia (fig. 2). Morphologic features of
Kamchatka, in particular, the Sredinny Range, extend into
the Highlands. This area is mountainous and has a very
complex and diverse geology, consisting of predominantly
oceanic and volcanic arc facies.

West of Kamchatka lies the Sea of Okhotsk. Interpreted
results of seismic reflection and refraction work and
dredgings indicates many structural features are present,
several of which are believed to be related to features on
Kamchatka (Cnibidenko and Khvedchuk, 1982). The most
relevant features include the Academy of Sciences Rise, the
Lebed Swell, the Bolsheretsk uplift and the Institute of

Oceanology Rise (fig. 3).

 

11

Figure 3 - Tectonic features of the Sea of Okhotsk
(after Cnibidenko and Khvedchuk, 1982)

 

12

 

 

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NORTHEAST SIIERIA

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Figure 3

METHODOLOGY

The methods used to determine the character and extent
of the terranes of Kamchatka are found in Jones et al.
(1983) and are summarized below. Terranes are defined as
"fault bounded geologic entities of regional extent, each
characterized by a geologic history that is different from
contiguous terranes" (Jones et al., 1983). The uniqueness
of the stratigraphic column, therefore, is the main
criterion by which a terrane is identified.
Paleontological, stratigraphic and lithologic data are used
to determine the stratigraphic sequence of a terrane while
geophysical data and data on major faults or suture zones
are used to delineate the extents of a suspect terrane.
The clarity with which a terrane or group of terranes is
identified is dependent upon the amount and quality of the
aforementioned controls.

The methodology used in the thesis for the terrane
analysis consisted of three steps. First, the literature
was studied to determine the stratigraphy of the regions of
Kamchatka, allowing for a tentative delineation of
terranes. Next, data on major faults, fault zones and
suture zones in conjunction with available gravity and
magnetic data allowed for the determination of the
boundaries of the terranes. Finally, general examination
of the geology and geophysics of tectonic features

surrounding Kamchatka provided the final constraints on the

13

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14
character and extent of the terranes. This final step also
involved the development of a tentative model for the plate
tectonic evolution of Kamchatka Peninsula. Constraints for
the model are provided not only by the elements of the
tectonic history of each individual terrane considered as a
whole but also by models for the relative motion of oceanic
plates in the Pacific Basin during Mesozoic and Cenozoic
time. Figure 27 is a tectonic/geology correlation chart
that summarizes the age, geology and tectonic activity of
the terranes and is presented after the geological

discussion.

as

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SOURCES OF UNCERTAINTY

Several factors limit the precision of the conclusions
reached in this study. Since the majority of the geologi-
cal data on Kamchatka are extracted from Soviet references,
an important element affecting the accuracy of conclusions
presented in this thesis are the differing methods of
interpretation of geologic data by Soviet and western
geoscientists. Commonly, there is a tendency by Soviet
geoscientists to describe geological phenomenon in the
terms of geosynclines, the concepts of which were outlined
by Aubouin (1965) and Kay (1951), a distinct contrast to
conventional plate tectonic theory originally outlined in
detail by Heirtzler et al. (1968), Isacks et al. (1968), Le
Pichon (1968) and Morgan (1968). The major difference in
these two approaches to the development of regional
tectonic models is the basis of geosynclinal theory on only
vertical crustal motions in contrast to horizontal crustal
plate motions that provide the basis for modern plate
tectonic theory. The emphasis is thus placed on vertical,
and not horizontal stress regimes and motions, in Soviet
interpretations. Consequently, data on geological
structures that resulted from horizontal maximum stresses
(esp., thrust faults) are not always described in the
literature, or are described from a vertical stress regime
and motions point of view. Information regarding them can

only be obtained indirectly by interpretation which can

15

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16
lead to inaccuracies.

Secondly, it is often difficult to separate raw data
collected in the field or the laboratory from conclusions
and extrapolations drawn in the paper or by other workers
referenced in the paper. In addition, scales and
directions usually left off of geological maps can render
otherwise good information unreliable and possibly
unuseable.

Lack of geological and paleomagnetic data increases the
uncertainties of the tectonic model. Available geologic
data density varies greatly throughout Kamchatka Peninsula,
ranging from sparse in the northern and western areas to
adequate in the central and eastern areas. Thus, terrane
boundaries are not always determined with precision and
some terranes may actually be composite terranes.

Extensive Quaternary volcanic and elastic deposits found
throughout the peninsula (fig. 4) obscure the older
formations and thus limit exposures of important geological
features. Paleomagnetic pole data that could very usefully
be used to determine relative motions, if any, between
various regions of Kamchatka or between these regions and
associated areas of geological interest have not been
determined. Thus, it is possible that relative motions
between various regions have occurred. These possible
motions include, in particular, syn- and post- accretionary
terrane translation, similar to what is observed to have

occurred in certain western North American terranes, e.g.,

 

17

Figure 4 - Quaternary geology map of Kamchatka Peninsula

 

 

 

19
Wrangellia (Jones et al., 1977).

The data sources used in the study include Soviet
literature and maps, primarily in translation but some in
Russian, and several international geological journals.
The major sources of literature include Doklady Akademii
Nauk USSR, International Geology Review, Geotectonics,
Lithology and Mineral Resources, Tectonophysics, Marine
Geology and Pacific Geology. Translations have also been
obtained from the United States Geological Survey. Several
different geological and tectonic maps were also

referenced.

 

20

Figure 5a - General geologic map of Kamchatka Peninsula

 

22

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a: «Cy
A. a 94' VIC . hit»
..1 u . . Y .Hu 1.. l 4
. . a: m_. w,‘ Wm AJ A: ”W. was. «a u .. 5““. NH nu.“ a. a. Md .‘1‘ .hU A: - .. i s O A. J
a . . l a . . . h: -. . .. a. .4 3 ..u . , «C a
l. n 0 . . T. n L n . . x u . — . "J a V. ... . . . . . a . .i. ... . all. Ti . n .. ~11 u w... a ... ‘4‘ w 3... WI.“ T x hwy. RN.”
. . I a .r .Ifi. L Ir . I... I r
‘ . E A 1“.

Figure 5b - Geological nomenclature

 

23

 

TERTIARY

clastics

Qs - Quaternary

Tmp - Miocene and Pliocene

Tm - Miocene

Tom - Oligocene and Miocene

To — Oligocene

Te - Eocene

Tpo - Paleocene to Oligocene

Tpe - Paleocene and Eocene

volcanics

Qv — Quaternary andesite and basalt

Tmpv - Miocene and Pliocene andesite and basalt

Tmu - Miocene undifferentiated volcanics

va - Miocene andesite and basalt

Tomv - Oligocene and Miocene andesite and basalt

Tou - Oligocene undifferentiated volcanics

Toi - Oligocene andesite

Tob — Oliogocene basalt

Tpeb - Paleocene and Eocene high alumina basalt

JURASSICLCRETACEOUS

Kl - Late Cretaceous clastics

Kli - Late Cretaceous andesite

Klo — Late Cretaceous ophiolite/upper oceanic layer

Ke - Early to middle Cretaceous clastics

JK - Late Jurassic arc volcanics and Early Cretacous
clastics

MESOZOIC

Mps - Mesozoic pelitic schist with abundant granitic
intrusions

Mgs - Mezozoic greenschist

Figure 5b

TERRANE ANALYSIS

Ten terranes are delineated in Kamchatka through
terrane analysis. The terrane map of Kamchatka (fig. 6)
and general characteristics (table 1) outline the extent
and nature of the terranes.

In this thesis, descriptions of the character and
extent of the terranes proceed generally from west to east,
in the approximate order of age and appearance in the
tectonic model, and are organized as follows.

First, the diagnostic characteristics of the terrane
will be given followed by a detailed description of the
stratigraphic column, starting with sedimentary suites and
followed by igneous formations. The geologic symbols used
on the columns are given on Figure 7. An estimate of the
approximate location of exposures of the important forma-
tions is given on fig. 8a with a list of the formations
given in Fig. 8b. Any paleontologic and/or radiometric age
data are included in this part of the section. Description
of the extent and character of the boundaries of the ter-
ranes and the relations of each terrane and surrounding ter-
ranes will be discussed. Each section will be concluded
with a review of the tectonic history of the terrane. After
the discussion of the geology of Kamchatka, the geology of
surrounding features of relevant interest and relative plate
motion data on oceanic crustal plates of the Pacific Basin

will be discussed. The final section will be devoted to the

24

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25
presentation of the model for the plate tectonic evolution

of Kamchatka, based on the presented data.

 

26

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Figure 6

Table 1

28

- General characteristics of the terranes of
Kamchatka

1

Tab I (’

29

 

 

 

 

 

 

 

 

 

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ocoo Cu 0» ozooogdz on Issac ou .mwao sucq Ca.>aacm o» zmgcm Ca naoocmr
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.Aawca ..odo> .o~o> .Aeucw .Avbcw CECE .Loucfi Cause ..e~c> .ACacq oxooz
\oamme .Caucfi Cause \OAQCE \owmas IonvzaEd .ouHHAQn .owudoh Cause \owmwe quCHEocCL;
. . . . mass mass A I mass mafia mafic mcwamc
ooqc; coda; ooamc IhooocH IntoCcH < x ItcoocH L< I x Ihmosch ILtCCCH he
"CCHCL "coda; "coda; "Coda; "ooqdm bongo:
mscooa .
rsooom «w nsooom «assoc w unococ w nsccom msoooc chcwc Iu;Lo .aopo mmoc:
Isaac zhc_unoe Iacgo Iucuo Iuogo Iucnc Igogo Io>oav hfiumm >~Lam gramme
Cam; hflscm Cad; Cum: CBC: mud; mama owmcmLSS ..H mama ..3 can; we ou<
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cxawcosm xacnode nomad: xumnoECx . chdz 0 . c> Louomcszo
taco .mta:;; snuococx cacsnmm caucuson Hmcmc xccwutcm x::_xadz cease conx x sewage?

 

 

 

 

 

 

 

 

 

 

 

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30

Figure 7 — Geologic symbols for the stratigraphic columns

 

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31

Siltstones, shales
Sandstones
Conglomerates

Tuff

Andesitic volcanics

Undifferentiated volcanics

Basalt

Granite

Diorite

Figure 7

x:
\
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//

Gabbro

Ultramafics

Pelitic schist

Greenschist

Thrust Fault (teeth on

upper plate)

Unconformity

Inoceramus age date

 

Radiometric age date

32

Figur
e 8a
- Estim
ated l
ocations of i
mportan
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mations

34

A.“ 2 «.(J ..% .../(O 7: «fly nJ/AJ 4II al\ ..a/

1474 1111

Alll 1|

Figure 8b - List of formations

4.

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4

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\OCDQO‘WbWN—HO

1O

35

Quaternary volcanics and sediments
Kvakhon/Kikhchik series'
Voyampol/Kavran series'
Omgon series

Tigil series

Kovacha series

Cape Kinkilsky suite
Iruney series

Lesnovo series
Kirganik suite

Anavgay series

Alney series

Kolpakova series
Malkinsk series
Khavyven series
Kelmenskaya suite
Yelovsk/Kavran series'
Valagin series
Stenovaya series
Khapitsk suite
Drozdovsk suite
Stanislavsk suite
Osipov series

Ganal series
Alney/Golyga series
Afrika series
Stolbovsk series
Tyushevka series

Cape Kamenistyy suite
Kronotsky series
Bogachevka/Chazhmin series

Figure 8b

Early

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KVAKHON TERRANE

The Kvakhon terrane, located between the Malkinsk
terrane and the Sea of Okhotsk (fig. 6), is a Late Jurassic
to Early Cretaceous island arc overlain by Late Cretaceous
and Tertiary sedimentary sequences (fig. 9). The terrane
is bounded on the east by an overthrust zone along which
exposures of blueschist mineral assemblages are found and
on the north by the "Diagonal suture" (Rotman, 1964).

The basement of the terrane is represented by the
Kvakhon series. Outcrops of the lower section of the
series are composed of mafic and ultramafic igneous rocks,
accompanied by serpentinite, and are exposed along the
eastern margin of the terrane. Blueschist metamorphism is
indicated by the presence of glaucophane and stilpnomelane
(Sidorchuk and Khanchuk, 1981; Shul'diner et al., 1980).
The upper section of the series consists of tuffs, shale
and sandstone with interbeds of intermediate and mafic
volcanics up to 200 meters thick (Cnibidenko et al., 1974;
Smirnov and Sinitsa, 1975), which are locally metamor-
phosed up to the greenschist facies level (Cnibidenko et
al., 1974). The age of the Kvakhon series is based on
fragments of a Late Jurassic to Early Cretaceous mollusk,

Inoceramus (Sidorchuk and Khanchuk, 1981; Smirnov and

 

Sinitsa, 1975). Various species of Inoceramus are often

 

used to date other Cretaceous sedimentary formations

throughout Kamchatka Peninsula.

36

37

Figure 9 - Stratigraphy of the Kvakhon terrane

 

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NEOGENE

PALEOGENE

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38

GUATERNARY

GAKHA
SUITE

KOVACHA SERIES

SNA'TOL
SUITE

NAPANA
SUITE

KIKHCHIK

SERIES

KVAKHON

SERIES

 

Figure 9

 

 

 

 

 

 

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a nu ... 7.1 p1 -..”. h. ea Q» 0 .1. a. «4. pa L. r
1 I. rt. a; S of; «q/ . n... r!» n 3 G. . 9.. E) -n . 1r .. a. .14 .p .. P.
at» ...I: fi\» rd «av .11. n1. 3. q ..1‘ - ~ ~4 flu 4| . . I e . Cu .- v ¢ ... t 4

39

The Kikhchik series, a middle Cretaceous to Santonian
terrigenous sequence, overlies the Kvakhon series and
consists of at least 300 meters of sandstones, siltstones
and shales that often contain siliceous material (Sidorchuk
and Khanchuk, 1981; Smirnov and Sinitsa, 1975). The age is
based on floral remnants only. The presence of pebbles of
glaucophane schist in the Kikhchik series suggests an
unconformity separates the Kikhchik and Kvakhon series.
Smirnov and Sinista (1975), however, describe the contact
as being conformable. Greenschist metamorphism of portions
of the Kikhchik series has occurred (Cnibidenko et al.,
1974) but no data are available concerning the
characteristics and the areal extent of the metamorphism.
Both the Kvakhon and Kikhchik series are thrust, possibly
in more than one thrust sheet, to the east over the western
margin of the Malkinsk block (fig. 10) with the blueschist
metamorphic rocks exposed at the base of the thrust sheet.
West of the thrust zone, the series dip westerly, 10° to
15° under the Tertiary deposits of the Bolsheretsk basin
with a slightly steeper dip towards the northern part of
the basin (fig. 10).

Tertiary sequences unconformably overlie the Cretaceous
sequences and consist predominantly of marine and
continental clastic facies. They are found to the west of
the Cretaceous exposures, in the area of the Kvakhon
terrane designated as the Bolsheretsk Basin (Cnibidenko et

al., 1974; Dmitriyeva, 1981; Fedynsky and Levin, 1970) and

 

 

40

Figure 10 — Cross-section of the Kvakhon and Malkinsk
terranes

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41

 

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42
are well constrained in terms of age by abundant faunal and
floral remains. In the southern and central portions of
the basin, sequences of Miocene to Quaternary age overlie
the Cretaceous rocks and have a thickness of 200 to 1000
meters. However, from the central part of the basin to its
northern extents, the Tertiary sedimentary column increases
in thickness up to 3500 to 4000 meters and includes Eocene
to Quaternary aged rocks. Eocene and Oligocene sequences
are therefore exposed only in the northern part of the
basin and wedge out in a southward direction.

The Napana and Sna'tol suites, the middle and upper
suites of the Tigil series, are exposed only in the
northern part of the basin. The lowest suite of the Tigil
series, the Khulgun suite, is not found in the Kvakhon
terrane but is identified in terranes to the north and east
of the Kvakhon terrane. The Napana suite is Early to
Middle Eocene in age and consists of sandstones and
argillites containing coal beds. The Sna'tol suite, Late
Eocene to Early Oligocene in age, consists of sandstones
and conglomerates with tuffaceous horizons. The combined
thickness of the Napana and Sna'tol suites is 1000 to 1500
meters. The middle to Late Oligocene Kovacha series
conformably overlies the Tigil series and consists of
siltstones, sandstones and argillite 300 meters thick.
Generally, the rocks of the Kovacha series are found in the
northern part of the basin but portions of the upper

section of the series are found further south,

43
transgressively overlying the older rocks (Dmitriyeva,
1981).

An unconformity separates the Voyampol series from the
underlying Kovacha series. The lowest suite of the
Voyampol series, the Gakha suite, consists of sandstones
and interbedded argillites containing calcareous members
and tuffaceous horizons. Conglomerate layers and basaltic
volcanic rocks are occasionally found. The suite is 200 to
600 meters thick and of Early to Middle Miocene age. The
Middle Miocene Utholok suite, 200 to 400 meters thick,
consists of siltstones and argillites with tuffaceous
members. The Middle to Late Miocene Viventek and Kuluven
suites consist of argillites and siltstones with
interbedded tuffs and calcareous horizons, 150 to 800
meters thick.

An angular unconformity separates the Voyampol series
from the Kavran series. The Il'insk and Kakert suites, the
base of the Kavran series, consists of sandstones,
siltstones and shales with layers of tuffs and
conglomerates. The thicknesses of the suites ranges from
200 to 500 meters and are Late Miocene to Early Pliocene in
age. The Etolon and Erman suites are middle to Late
Pliocene in age and consist of 200 to 600 meters of
sandstones with interbedded clays, coals and
conglomerates. Tuffaceous horizons are also present.
Throughout the Kavran series, pebbles of the underlying

Cretaceous and Tertiary series are found in conglomerates.

44

Quaternary fluvial deposits complete the stratigraphic
column of the Bolsheretsk Basin and hence, the Kvakhon
terrane. Structurally, the Tertiary rocks of the terrane
are almost horizontal, with only slight dips to the west,
and are gently folded. Intrusives consist solely of
Miocene granites located along the east-central margin of
the terrane.

The unconformable contact between the Cretaceous and
Tertiary sequences exposed along the eastern margin of the
terrane is traceable in the subsurface as a refracting
horizon (Fedynsky and Levin, 1970; Smirnov, 1971). The
horizon dips westward at angles not greater than 10° to 15°
but has a slightly steeper dip to the north (Marakhanov and
Potap'ev, 1981). The velocity of the refractor ranges from
5.2 to 5.7 km/sec but sometimes reaches 5.9 to 6.0 km/sec
(Smirnov, 1971). The range of velocities is indicative of
the presence of igneous and/or metamorphic rocks. Smirnov
(1971) has noted that no reflecting or refracting horizons
are visible in the seismic data beneath the refractor,
suggesting again that only igneous and/or metamorphic rocks
are present beneath the horizon. One drill hole in the
Ust—Bolsheretsk area penetrated an amphibolized gabbro at a
depth of 534 meters (Cnibidenko et al., 1974). The
association of the gabbro with a particular series cannot
be done with certainty. However, the depth correlates with
the general position of the refracting horizon in the area.

A major basement uplift, the Bolsheretsk Uplift, is

 

 

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45

located in the southern area of the terrane (fig. 10). It
has been identified from seismic and drilling work in the

area and is structurally contiguous with features located

in the Sea of Okhotsk (Cnibidenko and Khvedchuk, 1982).

The eastern boundary of the Kvakhon terrane is the
blueschist/thrust zone that extends along the length of the
Malkinsky block. South of the block, the boundary of the
Kvakhon terrane becomes buried under Tertiary deposits and
may be continuous with the Central Kamchatka Basin (fig.
6). The northern boundary of the Kvakhon terrane is the
"Diagonal geosuture" first described by Rotman (1964). The
"suture" is a zone of northwesterly trending faults
extending from the northern point of the Malkinsk block,
northwest into the Sea of Okhotsk just west of the town of
Moroshechnoye (fig. 2). Both strike-slip and normal faults
are found in the zone. In addition to the presence of the
faults, Rotman (1964) indicates other data for the
identification of a structural feature. The thickness of
Tertiary sequences is much thicker and includes Paleocene
strata north of the boundary, as compared to thinner Eocene
and younger strata found to the south of the boundary.
Cretaceous rocks are found at greater depths north of the
boundary than south of the boundary. Strike of folds north
of the boundary trend northeast and along the boundary
trend northwest while the strike of folds south of the
boundary in the Bolsheretsk Basin trend north. In

addition, alkaline basalt volcanoes of Neogene age common

7'“

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46
in western Kamchatka are absent south of the zone.

In summary, the tectonic history of the Kvakhon terrane
commences in Late Jurassic time with the onset and
development of island arc activity, designated as the
Kvakhon arc. The are associated volcanic and sedimentary
rocks, the Kvakhon series, were deposited onto oceanic
crust that is now exposed along the eastern margin of the
terrane. Taking into account the Late Jurassic to Early
Cretaceous age of the arc formations, the oceanic layer is
Jurassic, or older, in age. Arc activity ceased in Early
to middle Cretaceous time and was followed by a period of
uplift. Deposition of the Kikhchik series occurred during
middle Cretaceous to Santonian time. Late Cretaceous
uplift produced an unconformity between Cretaceous and
Tertiary rocks. Deposition of shallow marine and
continental facies commenced in the northern part of the
basin in Eocene time. Southward transgression of the
depositional environment occurred in Late Oligocene
through Miocene time and was the period of greatest
subsidence of the basin. These formations, including the
rest of the Miocene strata and the Pliocene strata, were
deposited in the Bolsheretsk basin. The presence of tuffs
in the Neogene sequence indicates the basin was in close
proximity to an active island arc during this time. This
fact, in addition to the lack of tectonic activity in the
Kvakhon terrane at this time (i.e., a quiet period of

sedimentation), suggests the Bolsheretsk basin may have

Ir.

Cw

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47
been a back arc basin, with an arc trench system located to
the east. During Late Pliocene or Quaternary time, the
terrane was uplifted above sea level, leading to the

current fluvial sedimentation.

OMGON TERRANE

The Omgon terrane lies to the north of the Kvakhon
terrane, across the "geosuture". The terrane has a thick
Cretaceous and Tertiary sedimentary column overlying either
oceanic or island arc igneous suites of Mesozoic age (fig.
11). The terrane is bounded on the south by the "diagonal
suture", on the east by an overthrust zone indistinctly
exposed, and extends north into the Kamchatka Isthmus.

Sparseness of available data on this region of
Kamchatka prevents a conclusive determination of the true
nature of the basement rocks. The oldest referenced rocks
are Early Cretaceous (Barremian or older) "volcanic rocks"
beneath the sedimentary column at Omgon Point whose
specific nature is not described (Voronkov and Smirnov,
1971). An unconformity separates the volcanic rocks from
the overlying sedimentary rocks. Krasny (1964) lists
outcrops of diorite and granite, both of Cretaceous age, at
Omgon Point and in the Moroschechnyy Range, respectively.
Cretaceous diabase outcrops one to two kilometers east of
the exposures of the granite. Neither the nature of the
contact between these rocks and overlying sedimentary
sequences nor the method of their dating is given. Exposed
in the basement of the Kinkilskaya anticline, located along
the western margin of the isthmus of Kamchatka (fig. 12),
is a sequence of Early Cretaceous mafic effusives
(Cnibidenko et al., 1974). The method of dating of these
basement rocks is not stated but is probably inferred from

48

49

 

Figure 11 - Stratigraphy of the Omgon terrane

 

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51

Figure 12 - Structural features of the Omgon terrane

 

52

 

 

 

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53
the middle Cretaceous age of the overlying sediments.

Exposed in at least three localities of the Omgon
terrane is an Albian to Santonian clastic sedimentary
sequence that unconformably overlies the igneous basement
rocks (Voronkov and Smirmov, 1971; Cnibidenko et al.,
1974). Voronkov and Smirnov (1971) name the sequence the
Omgon series and describe its exposures in two localities.
In the Moroschechnyy Range, the Tal'niki suite, the lower
suite of the Omgon series, consists predominantly of 1100
meters of shales with interbeds of siltstone and
sandstone. The unconformably overlying Maynachskaya suite
has a basal conglomerate and consists predominantly of 500
to 600 meters of sandstone with interbeds of siltstone and
shale. The suite is late Turonian to Santonian in age.

The beds of sandstone and shale are 150 to 200 meters thick
and often contain pyroclastic material. Conglomerate units
0.5 to 4 meters thick are sporadically found in the
sandstone units.

At Omgon Point, the series is nearly identical, with
shales predominating in the Tal'niki suite and sandstones
predominating in the Maynachskaya suite. One difference to
note between the exposures of the series at the two
localities, however, is the presence of somewhat more shale
and siltstone throughout the section at Omgon Point as
compared to the section exposed in the Moroschechnyy
Range. In addition, the Omgon series is dated by findings

of fragments of the middle and Late Cretaceous mollusk,

54

Inoceramus.

 

Exposed in the isthmus of Kamchatka, west of the
Kinkilskaya anticline zone, is the Lesnovo series, a
Cenomanian to Turonian sandstone and shale sequence, 3000
meters thick, (Krasny, 1964; Shapiro, 1981) that is
considered an eastern extension of the Omgon series
(Avdeiko, 1971). The lower portion of the series and the
base upon which it was deposited is not exposed. But
basement material is suggested to consist of rocks similar
to basement material exposed elsewhere in the Omgon terrane
(Avdeiko, 1971).

Other references to middle Cretaceous clastic sequences
in the Omgon terrane are Cnibidenko et al. (1974) who
briefly mention an Albian to lower Senonian (Santonian?)
terrigenous sequence exposed in the limbs of the
Kinkilskaya anticline and Smirnov (1971) who mentions
exposures of early Albian marine deposits found at Cape
Khayryuzov. Unfortunately, neither reference gives further
details, such as the method of dating of the rocks nor a
more precise stratigraphic and compositional description.
The general references do, however, demonstrate the
widespread occurrence of Early to Middle Cretaceous clastic
sequences throughout the Omgon terrane.

The Tertiary stratigraphy of the Omgon terrane is
essentially identical to the contemporaneous deposits of
the Kvakhon terrane in the terms of age, stratigraphic

division and composition. Two differences, however,

55
do exist. The Khulgun suite, the lowermost suite of the
Tigil series not found in the Kvakhon terrane is exposed in
the Tigil region of the Omgon terrane. The suite is
Paleocene in age and unconformably overlies Cretaceous
rocks. The suite consists of interlayered sandstones and
conglomerates, with a conglomerate sequence at the base,
and is up to 70 meters thick. The Early Eocene to Early
Oligocene Napana and Snatol' suites of the Tigil series
conformably overlie the Khulgun suite and consist of the
same facies in both the Omgon and Kvakhon terranes.
However, the middle and Late Oligocene rocks of the Omgon
terrane differ in the southern and northern regions. In
the southern region, the Kovacha series described in the
Kvakhon terrane section is identical to the contemporaneous
rocks of the Kvakhon terrane. However, in the northern
part of the Omgon terrane, the middle and Late Oligocene
rocks consist of the Cape Kinkilsky suite, made up of tuffs
and greenish sandstones overlain by undifferentiated lavas
and tuff breccias. The suite is up to 2500 meters thick
and contains an Oligocene flora (Nalivkin, 1973; Krasny,
1964). The rest of the Tertiary section, from the Early
Miocene through the Quaternary, is similar throughout the
terrane and consists of coarse and fine clastics in
addition to tuffaceous material. The series names are
referenced as the Voyampol and Kavran series, the same as
in the Kvakhon terrane. The sequences are generally

thinner in the Omgon terrane but are essentially

56
identical.

The Omgon terrane can be divided into several uplifts
and basins (fig. 12) that trend in a general north/south
direction. Cretaceous and Paleogene rocks are commonly
exposed along the axes of the uplifts. The Moroschechnyy
Range is a basement uplift bounded by faults and has middle
Cretaceous strata exposed in its central portions. The
Ambon anticlinorium is located at Ambon Cape and has Early
Tertiary strata exposed in the core. The Omgon
anticlinorium passes thru Omgon Point and has Cretaceous
and Tertiary sequences exposed in the axis and limbs. Only
middle Tertiary and younger strata are exposed in the
center of the Napana anticline. To the west and east of
the Omgon anticlinorium lies the Khayryuzov and Napana
basins, respectively, that are filled in with thick
Tertiary sedimentary column up to 3,000 meters thick
(Smirnov, 1971). Along the west coast of the isthmus of
Kamchatka lies the Kinkilskaya anticline, with Early
Cretaceous volcanic rocks exposed in the core and
Cretaceous sedimentary sequences exposed in the limbs.

As previously mentioned, the southern boundary of the
Omgon terrane is the "Diagonal geosuture" across which lies
the Kvakhon terrane. The suture is a zone of faults
trending northwest/southeast. The eastern boundary of the
terrane is the Tigil uplift or anticlinorium (fig. 6).
Mafic and ultramafic volcanic rocks containing blueschist

metamorphic mineral assemblages are exposed along the

57
uplift (Sidorchuk and Khanchuk, 1981; Dobretsov and Kuroda,
1974) and are suggested to be associated with steep folds
accompanied by thrust faulting described in the same area
(Dmitriyeva, 1981; Aprelkov and Zhegalov, 1972; Volynets et
al., 1965). This suture zone is a direct extension of the
Kvakhon/Malkinsky suture zone located to the south
(Sidorchuk and Khanchuk, 1981).

The continuation of the eastern boundary of the Omgon
terrane north from the Tigil region cannot be determined
precisely from the available data. The problem of the
position of the boundary occurs due to a lack of data on
the geology of the rocks exposed in the isthmus of
Kamchatka. Tentatively, the boundary is suggested to
extend approximately along the line that separates the
middle Cretaceous clastic outcrops to the west from
outcrops of Late Cretaceous oceanic crust to the east. The
highly deformed and thrust faulted character of the Late
Cretaceous rocks (Dmitriyeva, 1981; Aprelkov and Zhegalov,
1972) indicates that allochthonous layers of the oceanic
sequence may have been thrust in sheets for several
kilometers over the middle Cretaceous rocks located to the
west. The boundary zone is thus based on stratigraphic age
differences and the genetic origin of the rocks and not on
the presence of a major fault or suture zone.

The general tectonic evolution of the Omgon terrane is
as follows. Early Cretaceous arc activity is indicated by

the presence of pyroclastic material in the Omgon series

58
and by the Cretaceous diorite and granite found in the
Moroschechnyy Range and at Omgon Point. In addition, the
blueschist/thrust suture zone exposed in the Tigil uplift
is indicative of a Cretaceous (Jurassic?) subduction zone
and inferred island arc activity. The suture zone is a
direct continuation of the Kvakhon/Malkinsky suture zone
(Sidorchuk and Khanchuk, 1981) implying the arc facies of
the Omgon terrane may be the northern extension of the Late
Jurassic to Early Cretaceous Kvakhon arc.

The somewhat coarser clastics and the pyroclastic
material of the Omgon series found in the Moroschechnyy
Range as compared to the exposures of the Omgon series at
Omgon Point suggest the Moroschechnyy Range area may have
been located in closer proximity to the (active?) volcanic
arc during Cretaceous time than Omgon Point. The cessation
of arc activity is difficult to determine but most likely
occurred sometime in the Early Cretaceous, as evidenced by
the lack of abundant arc facies throughout the middle
Cretaceous Omgon series.

A break in the deposition of the fine clastics of the
Tal'niki suite occurred in Turonian time in response to a
general uplift. The event led to the unconformity that
separates the Tal'niki and Maynachskaya suites and to the
eastward transgression and deposition of the Lesnovo
series. The generally coarser clastics of the Maynachskaya
suite were deposited after the hiatus through Santonian

time.

59

A major unconformity from Campanian to Danian time,
approximately 20 Ma., separates the Cretaceous and Tertiary
sedimentary sequences. Deposition recommenced in Early
Tertiary time with the Tigil series, a sequence of shallow
marine and continental facies. The Khulgun suite, where
exposed, consists predominantly of conglomerates,
indicative of the onset of sedimentation.

The Tertiary strata are generally devoid of volcanic
material in the southern part of the Omgon terrane, except
for small amounts of Miocene and Pliocene tuffs and
Quaternary volcanics. In the northern part of the terrane,
clastic sedimentation occurred through Paleocene to Early
Oligocene time but middle and Late Oligocene rocks are
dominated by a sequence of undifferentiated volcanic
material. The period of volcanic activity had ceased by
Early Miocene time and was followed by a period of Miocene
to Quaternary sedimentation that also contains sporadic
volcanic material similar to what is found in the southern
part of the terrane. Uplift of the Tigil anticlinorium
occurred during Middle Miocene time while subsidence of the
Napana basin occurred in the Late Oligocene to Early

Miocene time.

SREDINNY RANGE TERRANE

The Sredinny Range terrane is located in central and

northern Kamchatka (fig. 6) east of the Omgon terrane and
west of the Central Kamchatka Basin. Generally, the
stratigraphy of the terrane includes the facies of two
island arc systems with basement rocks consisting of
oceanic crust (fig. 13). Extensive Neogene and Quaternary
volcanic cover obscures older formations, particularly in
the eastern and central regions of the terrane.

The basement of the terrane is the Iruney series, an
oceanic layer as indicated by abundant spilitic pillow
basalts, tuffs, jaspers, cherts, radiolarians and rare
limestone (Shapiro, 1981; Belyy, 1974). The series is
several kilometers thick and is exposed in the northern,
western and southern regions of the terrane but not in the
eastern and central regions. Occurrences of diabase,
gabbro, peridotite, pyroxenite and wehrlite amongst the
basalts are common (Cnibidenko et al., 1974; Belyy, 1974).
The Iruney series is equivalent to the "siliceous-volcan—
ogenous formation" commonly referred to in the Soviet
literature.

Conformably overlying the Iruney series is the Kirganik
suite of Campanian to Maastrichtian age. It consists of
coarse andesite and andesite-basalt volcanics with layers
of tuffs, tuffaceous sediments and chert and is up to 5000
to 6000 meters thick (Shapiro, 1981; Markov and Khotin,

1973). Exposures of the suite are found in the southern

6O

61

Figure 13 - Stratigraphy of the Sredinny Range terrane

62

 

 

 

     
 
  
   
  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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63
and northern parts of the terrane while exposures of the
suite in the central regions of the terrane are suggested
to be obscured, as with the Iruney series, due to abundant
Neogene volcanic and elastic cover.

The Iruney series and Kirganik suites are commonly
thrust faulted and highly deformed (Aprelkov and Zhegalov,
1972; Krasny, 1964). In the southern region of the
terrane, the rocks are considered allochthonous (Zhegalova,
1981) and are thrusted over the western margin of the
autochthonous Malkinsk block. Dunites, peridotites,
serpentinites and gabbros are exposed along the thrust
plane (Krasny, 1964). In the northern parts of the
terrane, the sequences are cut by numerous faults and are
steeply folded (Aprelkov and Zhegalov, 1972). In addition,
metamorphism up to the greenschist facies level has
occurred in response to the deformation of the rocks and to
the intrusion of Late Cretaceous, Early Tertiary and
Miocene granitic and gabbroic plutons (Dobretsov, 1975).

The Tertiary stratigraphy of the western portion of the
terrane differs from the stratigraphy of the remainder of
the terrane. Found along the Tigil uplift, in the western
part of the terrane, is the Paleocene to Early Oligocene
Tigil series made up of essentially identical facies as
described for the series in the Omgon terrane (Dmitriyeva,
1981). The middle and Late Oligocene Kovacha series
overlies the Tigil series and is also equivalent to

contemporaneous formations found in the Omgon terrane. The

64
Early to Late Miocene section of the region, the Voyampol
series, unconformably overlies the older rocks and consists
of interlayered tuffaceous sandstones and tuffs with
calcareous horizons generally containing more pyroclastic
material (tuffs), than the contemporaneous rocks of the
Omgon terrane. Completing the Neogene section in the
western region is the Late Miocene to Pliocene Kavran
series, made up of the Il'insk and Kakert suites consisting
of siltstones and tuffaceous sediments and the Etolon and
Erman suites consisting of sandstones, siltstones and
tuffaceous horizons. The Quaternary section consists of
plateau basalts and pyroclastics.

In the northern, central and southern regions of the
terrane, the Late Oligocene to Middle Miocene Anavgay
series unconformably overlies the Cretaceous rocks. The
Krapivninsk suite, the lower suite of the series, is 2500
meters thick and of Late Oligocene to Early Miocene age.
The base of the suite consists of alternating conglomerate,
sandstone and tuff that gradually change up the section
into andesite-basalt, andesite and tuff breccias with
layers of tuffite and tuffaceous sandstone (Rotman, 1960;
Shantser et al., 1965). The Berezovka suite, the upper
suite of the series, unconformably overlies the Krapivninsk
suite and is Middle Miocene in age. The suite consists
predominantly of tuff—breccias, tuffites, andesites and

dacites and ranges in thickness from 1100 to 1300 meters.

65
Both suites of the Anavgay series are dated by abundant
floral and faunal remains (Shantser et al., 1965).

Unconformably overlying the Anavgay series in the Alney
series, Late Miocene to Late Pliocene in age, that consists
of andesite-basalt, andesite, tuff—breccia and tuffs with
layers of fine to coarse grained clastic sediments. The
series is 1000 meters thick and has a basal conglomerate.
Completing the section of this region of the terrane are
abundant Quaternary basalt and andesite—basalt flows,
ranging in thickness from 500 to 1000 meters.

Many different lithological types of intrusives are
found in the Sredinny Range terrane. Late Cretaceous to
Early Tertiary intrusives consist of gabbros, diorites and
granites that intrude Late Cretaceous sequences
(Dmitriyeva, 1981; Krasny, 1964; Volynets et al., 1965).
These intrusives are found mostly in the northern portions
of the terrane. More extensively developed along the
entire length of the terrane are gabbro, diorite,
granodiorite and granite intrusives of Miocene age. Erlich
(1979) reports ten K-Ar radiometric age dates form the
granitoids of the Sredinny Range that have an average age
of 16 Ma (late - Early Miocene).

The Palana Basin is a major structural feature located
along the western margin of the Sredinny Range Terrane,
just east of the Tigil uplift (Dmitriyeva, 1981; Cnibidenko
et al., 1974). Exposed in the basin are Late Eocene

through Quaternary sediments and volcanics, with the

66
Miocene section being the thickest. Seismic data indicate
the thickness of the Tertiary deposits ranges from 1200 to
1500 meters, but sometimes reaches up to 3000 meters
(Dmitriyeva, 1981). The rocks of the basin are only
slightly tilted, 5 to 10 degrees, and are rarely folded
(Dmitriyeva, 1981).

The Sredinny Range terrane is bounded on the west by
the Tigil uplift and the tentative continuation of the
uplift to the north described in the Omgon terrane
section. The southwestern margin of the terrane is a
thrust faulted region where the oceanic crust of the Iruney
series and the overlying calc-alkaline volcanics of the
Kirganik suite are thrust in one, or several, sheets over
the Malkinsk block (Zhegalova, 1981). In this case the
Iruney series and the Kirganik suite are allochthonous.
Located along the eastern margin of the terrane is the
Central Kamchatka Basin (fig. 6). A geophysically
identified, elongate and narrow trough found along the
western margin of the basin is suggested to be related to
the subduction zone and trench system associated with the
eruption of the Late Cretaceous and Early Tertiary island
arc facies of the Kirganik suite (Rivosh, 1964).

The tectonic evolution of the Sredinny Range terrane
commenced in Santonian to Companian time with the
development of the calc—alkaline volcanics of the Kirganik
suite. The suite was deposited onto the Iruney series, a

pre-Santonian oceanic layer. Together, the Iruney series

67
and the Kirganik suite are referred to as the Iruney arc
(Belyy, 1974). The period of activity of the arc lasted
through Maastrichtian, possibly Danian, time. The trench
and subduction zone of the arc were located to the east, at
the present site of the trough identified by gravity and
magnetic anomaly lows found along the western margin of the
Central Kamchatka Basin. Thrust faulting and deformation
of the Cretaceous rocks occurred in latest Cretaceous or
earliest Tertiary time in response to accretion of the
terranes of eastern Kamchatka to the Iruney arc and the
terranes of western Kamchatka.

Deposition of elastic sequences commenced in Paleocene
time with initial subsidence of the Palana Basin occurring
in Late Eocene time. In Late Oligocene to Early Miocene
time, are activity of the middle Tertiary Sredinny Range
arc commenced. Contemporaneously, subsidence of the Palana
Basin continued but at an increased rate (Smirnov, 1971).
The trench and subduction zone associated with the arc were
located at the site of the Eastern Kamchatka Basin (fig.
25). The factors determining the tectonic relations
between the two areas are given in the section on the
geology of the Eastern Kamchatka Basin.

The rocks of the Sredinny Range are are located along
the entire length of the terrane. The Palana Basin,
located westward of the arc, is considered to be a back arc
basin that filled in with clastic and pyroclastic material

from the active volcanic arc. The period of activity had

68
ceased by Late Miocene or Pliocene time although sporadic
volcanism continued to occur. Plateau basalt flows of

Quaternary age conclude the tectonic sequence.

MALKINSK TERRANE

The most controversial area of Kamchatka is the
Malkinsk block, sometimes referred to in the literature as
the Central Massif. The problem arises because of the
inconclusive and contradictory radiometric and
paleontologic age data used to date the rocks of the
terrane, estimates of which range from Precambrian to Late
Cretaceous. The rocks in question generally consist of
felsic igneous intrusives and metamorphosed sedimentary and
igneous rocks (fig. 14). The complex tectonics of the
terrane and the high metamorphic grade of the rocks adds
uncertainty to the interpretation of the geological data.

The exposed basement of the terrane is the Kolpakova
series, a high grade metamorphic unit consisting of
migmatite, gneiss, crystalline schists and phyllites, the
parents rocks of which were a pelitic unit (Cnibidenko et
al., 1974; Lebedev et al., 1967; Krasny, 1964).
Plagioclase rich granitic plutons found in the series are
also metamorphosed. Overlying the Kolpakova series is the
Malkinsk series, a moderate grade metamorphic unit
containing three suites. The lowest suite, the Shikhtinsk
suite, consists of schist, gneiss and meta-pelite and has a
basal arkose conglomerate layer containing clasts of the
underlying metamorphosed granite and gneiss of the
Kolpakova series (Shul'diner et al., 1980; Shul'diner et
al., 1979). The Andrianovka suite overlies the Shikhtinsk

suite, and in some places, the Kolpakova series, and

69

 

70

Figure 14 - Stratigraphy of the Malkinsk terrane

71

 

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Figure 14

 

 

 

 

 

72
consists of greenschists with interbeds of coarse clastics
and tuffs (Cnibidenko et al., 1974; Shul'diner et al.,
1980). The volcanic rocks of the suite are at least
partially of intermediate composition (Krasny, 1964). The
suite has a basal tuff conglomerate layer exposed where it
directly overlies the Kolpakova series. The Shikhtinsk and
Andrianovka suites, and sometimes the Shikhtinsk suite
alone, are referred to as the Kamchatka series (Mokrousov
and Marchenko, 1964). The uppermost suite of the Malkinsk
series, the Kheivan suite, consists of micaceous
sandstones, phyllites and schists. The entire Malkinsk
series is 5000 to 5500 meters thick. Late Mesozoic to
Tertiary granites that intrude the series also intrude the
Kolpakova series and are not metamorphosed (Shul'diner et
al., 1980). The nature of the contact between the
Kolpakova and Malkinsk series is uncertain but is either
described as a thrust contact (Zhegalova, 1981) or an
unconformity (Shul'diner et al., 1980).

Tertiary sequences of the Malkinsk terrane consist of
isolated outcrops of the Barabskaya suite which contains a
Paleocene flora (Shtempel, 1957), and limited Quaternary
basalts and andesite volcanics and clastics. Several
Soviet authors (e.g., Cnibidenko et al., 1974; Zhegalova,
1981) include the Kvakhon and Kikhchik series of the
Kvakhon terrane and the Iruney and Kirganik series of the
Sredinny Range terrane in the stratigraphic column of the

Malkinsk terrane. Because these series are in tectonic

73

contact with the Malkinsk terrane and consist of different
lithofacies than the Kolpakova series, they are inferred to
be associated with their respective, separate terranes.

The metamorphic characteristics of the Kolpakova and
Malkinsk series differ considerably. The Kolpakova series
has undergone two phases of metamorphism. Mineral
assemblages that originated during the first phase increase
in grade moving west to east across the northern exposure
of the Kolpakova series, the area of the Khangar gneiss
dome (Shul'diner et al., 1980). The lowest grade
assemblage contains the minerals garnet, kyanite, biotite,
muscovite, plagioclase, potassium feldspar and quartz. To
the east lies assemblages consisting of garnet, kyanite,
biotite, plagioclase, potassium feldspar, quartz and
cordierite. Some of the K-spar is orthoclase. Another
assemblage consists of garnet, hypersthene, biotite,
plagioclase, potassium feldspar and quartz. These mineral
assemblages developed under high pressure and temperature
conditions of at least 6 to 8 kilobars of pressure and 600
to 750 degrees celsius and are indicative of amphibolite
grade metamorphism and possibly, granulite facies,
metamorphism (Shul'diner et al., 1980). In addition, the
event was not a contact metamorphic event because of the
increase in the metamorphic grade moving west to east over
a distance of several kilometers. This event, therefore,

most likely was a regional metamorphic event.

74

The second metamorphic event occurred under different,
lower grade conditions such that mineral assemblages of the
first event are altered to lower grade assemblages
(Shul'diner et al., 1980). Garnet is replaced by fine
grained biotite and muscovite. Kyanite is replaced by
muscovite and andalusite. Primary biotite is replaced by
muscovite and chlorite while cordierite is replaced by
spinel, muscovite, andalusite or sillimanite. The
secondary muscovite extends through the exposures of the
gneiss dome (Kolpakova series) while andalusite occurs
along the periphery and sillimanite occurs towards the
central regions of the dome. The abundance of andalusite
from the secondary metamorphism indicate an event of low
pressure (Shul'diner et al., 1980).

In contrast to the poly-metamorphic character of the
Kolpakova series, the Malkinsk series was metamorphosed
only once. The characteristics of the Malkinsk metamor-
phism are similar to the second event of the Kolpakova
series (Shul'diner et al., 1980). Characteristic mineral
assemblages found in the Shikhtinsk suite, the metamorphic
grade of which increases towards the base of the suite, in-
clude garnet, staurolite, biotite, muscovite, chlorite,
plagioclase and quartz found away from the contact with the
underlying Kolpakova series, and garnet, sillimanite, bio-
tite, muscovite, plagioclase and quartz found near the
contact (Shul'diner et al., 1980). Mineral assemblages of

the Andrianovka suite include chlorite, actinolite and

75

albite, and of the Kheivan suite, biotite, garnet,
staurolite and andalusite (Gnibidenko et al., 1974). The
mineral assemblages of the Malkinsk series developed under
moderate conditions of 2 to 4 kilobars pressure and
temperature of 450° to 600° celsius and are indicative of
greenschist facies metamorphism (Shul'diner et al., 1980).
In addition, the event occurred under conditions of a high
geothermal gradient and is most likely the result of a
regional metamorphic event. Generally, the metamorphic
rocks of the Malkinsk terrane consist of the amphibolite,
possibly granulite, facies rocks of the Kolpakova series
surrounded by the greenschist facies rocks of the Malkinsk
series, the metamorphic grade of which slightly increases
moving toward the Kolpakova/Malkinsk series' contact.

Paleontological dates from the Malkinsk terrane are
sparse and some may be questionable. The only dates
considered potentially reliable are indicated by the finds
of a Devonian and Carboniferous spore assemblage that is
considered very representative of spore complexes of that
age (A. Cross, pers. comm.). The assemblage is reported to
have been found in a biotite schist and a dark shale, both
from the Kheivan suite of the Malkinsk series (Sivertseva
and Smirnova, 1974). The report of a similar assemblage
from both metamorphosed and un-metamorphosed rocks lends
uncertainty to the validity of the finds since spores are
generally destroyed during metamorphic events over 150

degrees celsius (Tschudy, 1969). However, spores are very

76

durable in terms of weathering and reworking of older
rocks. The possibility therefore exists that the spores
may have been transported from the dark shale into
microfractures in the schist after the metamorphic event
occurred or from other blocks of Paleozoic age that are
present in the Central Massif. Aksenovich et al. (1964)
has described finds of Devonian, Carboniferous, Triassic
and Jurassic spores and Triassic flora from the Kikchik
series of the Kvakhon terrane, all of which are poorly
preserved. These data are confusing, conflicting and tend
to question the validity of any Paleozoic floral or faunal
remains in the Malkinsk series or Kamchatka. If Paleozoic
rocks are present, it is possible that blocks of Paleozoic
rocks exist or once existed in the Malkinsk terrane but
lack of geologic data on the area precludes this determination.

Radiometric age dates from the metamorphic rocks of the
terrane are numerous, but, their variety obscures a
determination of the age of the original rocks of the
terrane. Several dates from the metamorphic basement of
the terrane, either the Kolpakova or the Malkinsk series
have been obtained using the K—Ar isotopic method (Erlich,
1979; Kuz'min and Chukonin, 1980) (fig. 15). The ages
range from 314 to 15 Ma with three dates in the range from
103 to 90 Ma and with six dates in the range from 64 to 46
Ma. Three U-Pb dates averaging 1.36GA (Precambrian) have
been obtained from a biotite gneiss of the Kolpakova series

(Kuz'min and Chukonin, 1980). However, since only a few

 

77

Figure 15 - Potassium - argon radiometric dates from
Kamchatka Peninsula

78

 

 

NUMBER

I T
CAPE KAMCHATKA

I I
EASTERN RANGES

 

I I
SREDWNY RANGE

GANAL
I I '
SEA OF OKHOTSK

#4."!-
LJ-q- I . .

I I 1
MALHNSK BASEMENT

 

 

I r I -
MALMNSK GRANWES

   

 

0 TOTA L
5
0 I I I -I I I l 1
o ICC 200 300 400 500
AGE (Ma)

 

Figure 15

 

79
milligrams of zircon were available for testing, a method
of measuring Pb 207/Pb 206 ratios through thermionic
emission (Chukonin, 1978) was used. The method and
consequently, the results, are considered questionable due
to the unconfirmed method of isotopic measurement in
conjunction with the small amount of zircon used in the
study. Kuzmin and Chukonin (1980) also provide several
K—Ar radiometric age dates from the Kolpakova series and
indicate the rock type or mineral that was tested (table
2). Utilizing the data of Hyndman (1972, pg. 328)
indicating which minerals best retain the radioactive decay
daughter isotope, argon, during metamorphism, a plot is
obtained (fig. 16) that reveals an upper age limit of 78 Ma
for the metamorphic event. In summary, the metamorphism of
the Kolpokova series occurred around or before 78 Ma
(Campanian) indicating an older age for the deposition of
the parent rocks of the series. No radiometric data are
available on the Malkinsk series.

Intrusions into the Malkinsk terrane consist
predominantly of granite and granodiorite of Mesozoic and
Cenozoic age. Granite intruding only the Kolpakova series
are metamorphosed but those intruding both the Kolpakova
and Malkinsk series are not. Ages of the granites are
determined by the K-Ar isotopic method and range from 192
to 30 Ma, with 70% of the dates clustering in the period
from 50 to 40 Ma (Cnibidenko et al., 1974).

The characteristics of the boundaries of the Malkinsk

terrane with the Kvakhon and Sredinny Range terranes has

 

80

Table 2 - Potassium — argon radiometric dates from the
Kolpakova series of the Malkinsk terrane

81

 

 

 

Table 2
ROCK TYPE NO. OF DETERMINATIONS AVERAGE AGE (Ma)
gneiss 8 78
gneissoid granite 5 85
biotite - from a 2 53
gneissoid granite
plagiogranite 12 57
biotite - from a 4 47
plagiogranite
biotite 3 44
muscovite — from a 3 53
pegmatite
feldspar - from a 3 45
pegmatite
biotite - from a 1 41
biotite gneiss
plagioclase - from a 1 74

biotite gneiss

 

82

Figure 16 - Age estimate of metamorphism of the Malkinsk
terrane based on argon retention potential of
various minerals

83

  
  

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84

already been described in preceding sections. The
southeastern boundary of the Malkinsk terrane is the normal
faulted, narrow graben of the southern portion of the
Central Kamchatka basin. This boundary also extends along
the entire eastern margin of the Sredinny Range terrane.

The tectonic evolution of the Malkinsk terrane is as
follows. Deposition of the pelitic rocks that were the
parent rocks of the Kolpakova series occurred in late
Paleozoic or early Mesozoic time, possibly on oceanic
crust. This age is based on the Early Jurassic radiometric
age dates from granites of the terrane that indicate an
upper age for their formation, and consequently, for the
deposition of the parent rocks of the Kolpakova series.
High grade metamorphism throughout Jurassic time related to
subduction zone activity transformed the pelitic unit into
the amphibolite grade crystalline schists and gneisses of
the Kolpakova series. This metamorphic activity was
probably accompanied by the intrusion of granitic and
granodioritic plutons that were subsequently deformed by
continued tectonic activity. Post—orogenic emplacement of
the plutons probably also occurred. The origin of the
volcanics of the Andrianovka suite and the clastics of the
Kheivan suite is uncertain. Possibly, the Andrianovka
suite was deposited (erupted) during the period of
subduction that metamorphosed the Kolpakova series.
Subsequent subsidence of the block led to the deposition of

the Kheivan suite. A later period of uplift, erosion and

85
metamorphism, possibly due to an accretionary event,
exposed the metamorphic core of the Kolpakova series and
removed all but the outer margins of the Malkinsk series.
An alternate, although still tenuous, hypothesis is the
Andrianovka and Kheivan suites are allochthonous sheets
that developed separately from the Kolpakova series but
were thrust over and obducted onto the series in Jurassic
or Cretaceous time. The metamorphism of the series, and
the second period of metamorphism of the Kolpakova series,
would result from the dynamothermal processes of the
accretionary Obduction event. Development of Late
Cretaceous and Tertiary granitic plutons in response to the
nearby volcanic are activity of the Late Cretaceous Iruney
arc and the Neogene Sredinny Range arc may also have
metamorphosed to a certain extent the Kolpakova and
Malkinsk series. At any rate, the obduction hypothesis
would explain the metamorphic grade differences between the
Kolpakova and Malkinsk series, the increase in grade of
metamorphism towards the Kolpakova/Malkinsk contact, i.e.,
at the base of the Shikhtinsk suite, and the rubble found
at the base of the Malkinsk series.

Obduction of the Kvakhon terrane onto the Malkinsk
terrane is suggested to have occurred by 97 Ma
(Cenomanian), one of the clustering ages of radiometric
dates from the Kolpakova series. Other evidence favoring a
period of uplift in western Kamchatka at this time is the

late Cenomanian to Turonian unconformity separating the

86
Tal'niki and Maynachskaya suites of the Omgon series of the
Omgon terrane and the thick clastic section of the Lesnovo
series found in the eastern and northern regions of the
Omgon terrane. Cnibidenko et al. (1974) has pointed out
stratigraphic similarities between the Kvakhon and Kikchik
series of the Kvakhon terrane and the Andrianovka and
Kheivan suites and suggests the two units are the same,
except that a regional metamorphic event altered the
Malkinsk series. It is possible then that the Malkinsk
series is an allochthonous thrust sheet of the Cretaceous
rocks of the Kvakhon terrane. Lack of paleontological
remains in the Malkinsk series that are described in the
Cretaceous rocks of the Kvakhon terrane does not support
this idea although the metamorphic grade of the Malkinsk
series may explain their obscurity.

The clustering around 40 to 50 Ma of radiometric age
dates from both the metamorphic rocks and the granitic
plutons corresponds to a major Early Tertiary accretionary
and consolidation episode, including the thrusting of the
Iruney are over the eastern margin of the Malkinsk
terrane. It is suggested that the metamorphic conditions
induced by a thermal disturbance during this time released
argon from the granitic and metamorphic rocks of the
terrane. The K-Ar dates consequently reflect the date of
the accretionary event.

Neogene and Quaternary igneous activity led to the

development of Miocene granites and Quaternary volcanics

87
and clastics.

The Eifelian (Middle Devonian) age of spores in the
Khievan suite reported by Sivertseva and Smirnova (1974) is
identical to that of fauna found in sediments overlying the
Ust-Belaya ophiolite complex found to the north of
Kamchatka in the Koryak Highlands (Fujita and Newberry,
1983). In addition, Devonian rocks are also found in a
Mesozoic subduction complex in southwestern Japan that are
suggested to have been emplaced during a period of
transcurrent motion or oblique subduction in Mesozoic time
(Taira et al., 1983). The possibility therefore exists
that fragments of Devonian aged blocks have been rafted
northward along the Mesozoic Asiatic margin in a manner
similar to what has been observed in certain western North
American terranes, such as Wrangellia (Jones et al., 1977),
leading to the emplacement of the Paleozoic rocks along the

Japanese and Northeast Siberian coasts.

CENTRAL KAMCHATKA BASIN

The Central Kamchatka Basin is bounded by the Eastern
Ranges and Karaginsky Island on the east and by the
Sredinny Range and Malkinsk terranes on the west (fig. 6).
The basin extends from the Ganal Range in the south, north
through Litke Strait and into the Koryak Highlands. The
width of the basin is approximately 60 kilometers from its
northernmost extent to the central region and from there,
south to the Ganal Range, the basin narrows to a thin
graben, varying in width from two to eight kilometers.
Generally, the basin is underlain by oceanic crust overlain
by Oligocene, possibly Paleocene and Eocene, and younger
volcanics and clastics (fig. 17). Extensive Quaternary
volcanic and elastic cover obscures the older formations.

Evidence for an oceanic layer underlying the terrane is
as follows. The Khavyven Uplift is located southwest of
Ozernoy Peninsula and is suggested to represent an outcrop
of metamorphosed basement rocks (Gnibidenko and Marakhanov,
1973). The rocks consist of greenschists and
microquartzites, 1000 to 1500 meters thick, containing
mafic and ultramafic intrusives (Gnibidenko and Marakhanov,
1973; Shul'diner et al., 1979). Characteristic minerals
include chlorite, epidote, actinolite, albite, quartz,
biotite, muscovite and tremolite and are indicative of
epidote-amphibolite facies metamorphism. Garnet is also
present but rare. The parent material of the complex was

a mafic volcanic and sedimentary complex, indicated by the

88

 

Figure 17 — Stratigraphy of the Central Kamchatka Basin
terrane

90

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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91
composition of the metamorphic rocks. K-Ar radiometric age
dates ranging from 122 to 92 Ma have been obtained and most
likely indicate a metamorphic event (Gnibidenko and
Marakhanov, 1973).

Seismic velocities of 5.7 to 6.5 km/sec from a
refracting boundary lying at depths of 3 to 7 kilometers
determined in a refraction profile across the central
region of the basin are indicative of an oceanic layer
(Utnasin et al., 1975). On the basis of high gravity
( A g) and magnetic anomalies (A Ta) trending along the
eastern half of the basin, Rivosh (1964) concluded that
dense material (e.g., mafic effusives) lies at depths of
1.5 to 2 kilometers in the basin. The magnitude of the
anomalies decrease (fig. 18) corresponding to a general
increase in depth to basement in the same direction
(Rivosh, 1964). Low magnitude anomalies extend along the
entire western margin of the basin as a narrow band and
indicates the position of an elongate and narrow, sediment
filled, trough (Rivosh, 1964). The oceanic crust of the
basement, therefore, lies at shallow depths in the eastern
and central parts of the basin and at greater depths along
the eastern margin of the Sredinny Range terrane.

The sequences filling the basin are 2000 to 5000 meters
thick and are of Oligocene to Quaternary age. The
Paleogene and Neogene rocks are exposed only in the
northern part of the basin, west of Ozernoy Peninsula.

These formations, and/or other Paleogene or Cretaceous

92

Figure 18 - Magnetic anomaly map of Kamchatka Peninsula
(after Gnibidenko et al., 1974)

93

 

 

 

 

 

r
NETE

 

 

posmve ANOMALY
~ -NEGATIVE ANOMALY
0 q) ‘wOKm

 

Figure 18

 

94

sequences are obscured by Quaternary cover in the remainder
of the basin.

The lowermost suite overlying the basement is unnamed
and consists of andesites, basalts, tuffs, tuffaceous
sandstones and conglomerates. There are no age data on
this sequence. Overlying the unnamed suite is the
Kelmenskaya suite consisting of 1000 meters of interbedded
tuffaceous sandstones and siltstones. Paleontologic data
indicate a tentative Oligocene age (Mironoba, 1982). The
Yelovsk suite, conformably overlying the Kelmenskaya suite,
is Miocene in age and consists of 2500 meters of tuffaceous
sandstones, siltstone and argillites with interbedded
conglomerates. The unconformably overlying Kavran series
of Late Miocene to Pliocene age consists of 500 to 600
meters of tuffs and tuffaceous sandstones. Quaternary
andesites, basalts and their associated pyroclastics in
addition to elastic deposits complete the section of the
Central Kamchatka Basin.

The western boundary of the terrane, across which lie
the Sredinny Range and Malkinsk terranes, is the
geophysically identified, elongate and narrow trough often
accompanied by normal faulting. The eastern margin of the
terrane, across which lies the Eastern Ranges, Ganal and
Southern Kamchatka terranes (fig. 6), is a zone of thrust
and/or normal faults. The boundary separates the uplifted
Eastern Ranges from the downdropped Central Kamchatka

Basin. Seismic refraction data indicate the basement of

95
the basin is downdropped 1500 meters with respect to the
Late Cretaceous formations of the Eastern Ranges (Potap'yev
and Marakhanov, 1974).

The tectonic evolution of the Central Kamchatka basin
terrane is tentatively proposed to be related to the
development of the Iruney arc of the Sredinny Range terrane
and the Eastern Ranges arc of the Eastern Ranges terrane in
Late Cretaceous time. Initiation of activity of the two
arcs is proposed to have entrapped a fragment of Late
Mesozoic oceanic crust. As subduction activity continued,
the basin narrowed until in latest Cretaceous time, the
accretion of the arcs compressed the entrapped oceanic
fragment leading to metamorphism of the upper portion of
the oceanic layer, an example of which is exposed in the
Khavyven Uplift. The axis of the gravity and magnetic
anomalies extending through the basin corresponds to the
axis of the folded, uplifted and deformed oceanic layer.

Paleogene and Neogene calc-alkaline volcanics in the
basin are probably volcanic products of the Oligocene to
Miocene Sredinny Range arc. Volcanic activity in the basin

continued through Quaternary time.

EASTERN RANGES TERRANE

The Eastern Ranges include the Valaginsky, Tumrok and
Kumroch Ranges and the northern part of the Ganal Range
(fig. 2) and are collectively referred to as the Eastern
Ranges terrane. The stratigraphy is continuous along the
entire length of the ranges and is consistent with it being
one tectonic structure. The important features of the
terrane are the oceanic crust of the basement overlain by
Late Cretaceous to Early Tertiary arc facies. Tertiary
sequences are exposed only along the eastern margin of the
terrane and consist predominantly of clastics (fig. 19).
Extensive Quaternary volcanic cover obscures the older
formations.

The basal sequence found in the Valaginsk and Tumrok
Ranges is named the Valaginsk series whereas in the Kumroch
Range the Vetlovsk and Khapitsk suites are the equivalent
of the Valaginsk series. The Khapitsk suite is commonly
the name given to the uppermost of four suites of the
Valagin series. The Stenovaya series, described in the
northern part of the Ganal Range along the southern margin
of the Eastern Ranges terrane, is a metamorphic outcrop of
the lower sections of the Valagin series. Each of the
three basement formations of the various portions of the
terrane are considered separately.

The Valagin series has four stratigraphic levels with
the lower three being unnamed while the uppermost is called

the Khapitsk suite (Rotman et al., 1973). For clarity, the
96

 

97

Figure 19 - Stratigraphy of the Eastern Ranges terrane

98

   
 
 
    
   
    
    
 
 
    
    
  

OUATERNARY

OSIPOV
SERIES

  

CHAZMIN
SUITE

STANISLAVSK
SUITE

 

BUSHUYKA
SUITE

 

PALEOGENE

     
     
  

.<

   

     
   
   
    
  
   
   

5

KHAPITSK
SUITE

UPPER
SUITE

MIDDLE
SUITE

   

 
 

g
S
2

LATE

CRETACEOUS

  
  

LOWER
SUITE

2%?

E
El

JURASSIC

Figure 19

 

 

 

 

99
lower three suites will be called the lower, middle and
upper suites in ascending order. The rocks of the lower
suite are represented by basalts, spilites, tuffs and
cherts containing small amounts of argillite, siltstone,
and limestone (Gnibidenko et al., 1974). Diabase and
gabbroic rocks are commonly found. This sequence is the
equivalent of the "siliceous—volcanogenous formation" term
also used to describe the Iruney series of the Sredinny
Range terrane, and is an outcrop of oceanic crust. The
middle suite consists of sandstones and black argillites
with subordinate amounts of tuffaceous material. The upper
suite consists of sandstones, tuffs and cherts. The middle
and upper suites have a combined thickness that may reach
up to 6 to 7 kilometers. The Khapitsk suite, the uppermost
suite of the Valagin series, consists of andesite and
basalt volcanics, with layers of tuffs, tuffaceous clastics
and cherts (Shapiro, 1981; Markov et al., 1969). Thickness
of the suite is at least 2500 kilometers. Each suite of
the Valagin series grades into the others.

The metamorphic rocks of the Stenovaya series are
exposed in the southernmost region of the terrane and
contains three suites (Herman et al., 1978). The lower
suite is about 1000 meters thick and consists of
meta-volcanic rocks, tuffs, lavas and breccias of quartz
keratophyre composition, with interbeds of mafic schists,
phyllites and quartzites. The middle suite contains

interbedded felsic and mafic meta-volcanics 700 to 800

100
meters thick. The upper suite consists entirely of mafic
schists with some phyllites and is at least 1500 meters
thick. Generally, the rocks of the series are of
epidote-amphibolite metamorphic grade at the Ganal/Eastern
Ranges contact. North of the contact, the metamorphic
grade of the Stenovaya series decreases (Herman et al.,
1978) and grades into unmetamorphosed rocks of the
Valaginsk Range (Lebedev et al., 1967), presumably the
Valaginsk series. Although the rocks of the Stenovaya
series are described as containing a predominance of quartz
keratophyre in the lower sections, the genetic association
of the keratophyre and the mafic schists, commonly found in
upper oceanic layers, correlates with the oceanic crust
exposed at the base of the Valaginsk series. Therefore,
based on the genetic association and the metamorphic
gradient, the Stenovaya series is suggested to be the
southernmost exposure of the Valaginsk series that became
metamorphosed during an accretionary episode.

In the Kumroch Range, the Vetlovsk suite, as described
by Markov et al. (1969), may be divided in three
sub-suites. For clarity, the suites will be called the
lower, middle and upper sub-suites. The lower sub—suite is
represented by diabases, spilites, cherts and tuffs. The
middle sub-suite is a sequence of interbedded sandstones
and silty argillites, containing calcareous sandstones,
limestones and chert. The upper sub-suite consists of fine

clastics and limestones with chert interbeds that changes

101
up the section into coarse grained sandstones and
conglomerates. The Vetlovsk suite has a total thickness of
3700 to 4000 meters and is conformably overlain by the
Khapitsk suite. Rocks of the Khapitsk suite exposed in the
Kumroch Range are identical in composition to the exposures
of the same suite in the Valaginsky and Tumrok Ranges. The
exposures of the Khapitsk suite in the Kumroch Range are,
however, 1500 to 1800 meters thick compared to the 2500
meter thickness of the Valaginsk and Tumrok Range
exposures.

Thus, comparison of the stratigraphy in the northern
Ganal Range, and the Valaginsk, Tumrok and Kumroch Ranges
reveals their similarities in that basement material
consists of an oceanic layer (the lower suite of the
Valaginsk series, the genetic association of the Stenovaya
series, and the lower sub-suite of the Vetlovsk suite)
overlain by a sequence of fine to coarse clastics (the
middle and upper suites of the Valaginsk series and the
middle and upper sub-suites of the Vetlovsk suite). Along
the entire length of the ranges, these formations are
overlain by the intermediate volcanics of the Khapitsk
suite.

Ultramafic rocks of various composition are exposed
amongst the volcanics of the Khapitsk suite in the Tumrok
and Kumrock Ranges (Pushcharovskiy et al., 1983; Rotman et
al., 1973; Seliverstov and Tsikunov, 1974; Markovskiy and
Rotman, 1971; Krasny, 1964). Rotman et al. (1973)

102

describes two exposures of the ultramafic rocks in the
Tumrok Range. To the northwest and west of the lake lies
the "Tolbachinsk" complex consisting of pyroxenites,
wehrlites, serpentinites and olivinites. Outcrops of
gabbro and gabbro-syenite are common. The "Ostantsovsk"
complex lies to the west of the lake and consists of
gabbro, gabbro-diorite, harzburgite and dunite. A K-Ar
radiometric age date of 8OMa was obtained from the
ultramafics of this complex (Rotman et al., 1973). In both
complexes, the rocks are described as dikes, sills and
pyroclastics although no metamorphic contact zones are
described. In addition, the presence of blocks of
limestone in the vicinity of the ultramafics (Rotman et
al., 1973) indicates the rock association may represent a
subduction zone melange complex.

The age of the Valaginsk series and the Vetlovsk suite
is based on only a few observations. Fragments of Late

Cretaceous Inoceramus found in the upper suite of the

 

Valaginsk series (Rotman et al., 1973) constitute the only
paleontological data from these formations. A Late
Cretaceous age is also implied by the Paleocene age of the
overlying Drozdovsk suite.

The age of the Stenovaya series is also considered to
be Late Cretaceous, based on the genetic similarities with
the Late Cretaceous Valaginsk series. However, several
authors (e.g., Herman et al., 1978; Shul'diner et al.,

1979) contend the series is Ordovician, or older, in age,

103
based on one Rb-Sr radiometric age date of 487 Ma obtained
from the center of the "least altered plagiogranite
porphyry" stock intruding the series. The date is
considered questionable due to the genetic relations
between the Stenovaya and Valaginsk series that indicate a
common tectonic origin and a consequent, inferred Late
Cretaceous age for the Stenovaya series. A K-Ar
radiometric age of 60 Ma obtained from the same rock
(Herman et al., 1978) suggests an Early tertiary age for
the granite and a Late Cretaceous or Early Tertiary age for
the Stenovaya series.

The Drozdovsk series overlies the Khapitsk suite and
consists of alternating beds of sandstones and argillites
containing calcareous and sometimes tuffaceous, horizons.
Thickness of the suite ranges from 1000 to 2500 meters
(Rotman et al., 1973; Markov et al., 1969). The contact
between the Drozdovsk and Khapitsk suites is described as
both conformable and unconformable (Rotman et al., 1973).
The age of the suite is defined by the remains of a Danian
to Paleocene benthonic foraminifer assemblage found in the
Tumrok Range and a planktonic foraminifer assemblage of
Early Paleocene age found in the Valaginsk Range (Serova et
al., 1970). The fossils date the Drozdovsk suite and imply
a Late Cretaceous age for the underlying Valaginsk series
and Vetlovsk suites.

Overlying the Drozdovsk suite with only a minor

unconformity, and found only in the areas of the Gamchen

104
Range, along the eastern margin of the Eastern ranges
terrane (fig. 2), are the Bushuyka and Stanislavsk suites.
The Bushuyka suite consists of 400 meters of andesitic
tuffs and cherts while the conformably overlying
Stanislavsk suite consists of 1500 meters of sandstones and
siltstones (Shapiro and Seliverstov, 1975). Both suites
are devoid of paleontological remains, preventing an
accurate dating although a Paleogene age is inferred from
the underlying Paleocene Drozdovsk suite and the overlying
fine clastics of the Early Miocene Chazhmin suite.

The Late Miocene to Pliocene Osipov series overlies the
Chazhmin suite and consists of 2500 meters of elastic
sediments. Extensive Quaternary andesite and basalt
volcanics in addition to clastics of the same age complete
the stratigraphic section of the Eastern Ranges terrane.

It should be noted that volcanic arc facies of Late
Oligocene and Miocene age, most likely related to
contemporaneous deposits found on the Sredinny Range, Canal
and Southern Kamchatka terranes, are found along the
southern margin of the Eastern Ranges terrane. Their
description is found in the Sredinny Range and Southern
Kamchatka terrane sections.

Along the western margin of the terrane lie several
large thrust faults dipping southeast 30° to 40° with a
displacement of 10 to 12 kilometers (Tsikunov and Petrov,
1973; Tikhonov, 1968). The faults have thrust the

Drozdovsk suite over the Khapitsk suite and the Khapitsk

105

suite over the lower sections of the Valaginsk series
(Tsikunov and Petrov, 1973; Florenskiy and Florenskiy,
1972). The age of development of the faults is suggested
to be Late Cretaceous or Early Tertiary to Middle Miocene,
determined on the basis of the faulted Paleogene and Early
Miocene rocks but relatively undeformed Late Miocene and
younger rocks (Tsikunov and Petrov, 1973; Pushcharovskiy et
al., 1983). Folds in the Late Cretaceous to Early Miocene
rocks of the terrane trend generally north—south to
northeast-southwest (Gnibidenko et al., 1974; Shapiro and
Seliverstov, 1975). Along the southern margin of the
terrane, the folds trend northwest to southeast,
paralleling the Eastern Ranges/Ganal terrane boundary.

The Eastern Ranges terrane is bounded by large faults.
The western boundary is described specifically as a normal
fault (Legler and Florenskiy, 1976; Florenskiy and
Florenskiy, 1972) or generally as a large fault (Tsikunov
and Petrov, 1972; Potap'yev and Marakhanov, 1974;
Suprunenko, 1976; Erlich, 1979) lying immediately to the
west of the previously described system of thrust faults
(fig. 20). This fault zone separates the Eastern Ranges
terrane from the Central Kamchatka Basin. The southern
margin of the Eastern Ranges terrane is a southwesterly
dipping thrust fault along which the Ganal terrane is
thrust to the north—northeast over the rocks of the
Valaginsky Range (Herman et al., 1978). The fault extends

from the Central Kamchatka Basin, southeast to the northern

106

Figure 20 - Cross—section of eastern Kamchatka

107

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108
shore of the Avacha Inlet (Gnibidenko et al., 1974;
Gnibidenko and Svarichevskaya, 1984). Finally, the eastern
boundary of the terrane is the highly deformed and faulted
Eastern Kamchatka Basin, the geology of which resembles the
characteristics of an accretionary wedge (fig. 25).

The tectonic evolution of the Eastern Ranges terrane
commenced in Late Cretaceous (Cenomanian-Turonian?) with
the deposition of the shales and sandstones (turbidites?)
on Mesozoic oceanic crust. Coarsening of the clastic
sequences higher in the section indicates the oceanic crust
had moved into closer proximity to the source terrane of
the detritus, possibly the amalgamated terranes of western
Kamchatka. Development and activity of the Eastern Ranges
arc occurred in Late Cretaceous time and lasted through
latest Cretaceous, possibly earliest Tertiary, time, a
period that coincides with the activity of the Iruney arc.

Cessation of activity of the are led to the deposition
of the elastic Drozdovsk suite in Paleocene time. Absence
of Eocene and Oligocene formations, except possibly along
the eastern margin of the terrane, indicates the Eastern
ranges were uplifted and subjected to erosion during this
time period. The cause of the uplift may have been related
to the accretion of the Eastern Ranges to western
Kamchatka, an event which led to the deformation and
metamorphism of a portion of the oceanic basement of the
terrane, the Stenovaya series.

Minor clastic sedimentation and volcanic activity

109
occurred from Eocene through Early Miocene time. Middle
Miocene time was a period of uplift accompanied by
extensive thrust faulting and folding of the pre—Middle
Miocene rocks of the terrane and was followed by a period
of Late Miocene to Pliocene sedimentation. This orogenic
activity is related to the accretion of the Kronotsky
terrane to the eastern margin of the Eastern ranges and to
the development of a new subduction zone at the site of the
present day Kuril-Kamchatka trench. Volcanic activity
associated with this trench commenced in Pliocene time, but

was most extensive during Quaternary time.

GANAL TERRANE

The Ganal terrane, located between the Eastern Ranges
and Southern Kamchatka terranes, consists of mafic schists
of various metamorphic grades overlain by Tertiary volcanic
and elastic sequences (fig. 21).

The exposed basement of the terrane consists of the
Ganal series, outcrops of which extend southeast from the
Central Kamchatka basin to the northern shoreline of the
Avacha Inlet (Gnibidenko et al., 1974; Erlich, 1979). The
series is 2500 to 3000 meters thick and is represented by
moderate to high grade metamorphic mafic schists containing
intercalcations of pelitic schists, quartzites and marbles
(Shul'diner et al., 1979). Petrological analyses of the
schists indicate the parent rocks of the Ganal series were
alkalic to tholeiitic basalt of oceanic origin (Rozen and
Markov, 1973). In addition, Tararin (1977) and Gnibidenko
et al. (1974) suggest the parent rocks consisted of
diabase, spilite, tuffs, andesite porphyry, dacite,
siliceous-volcanics, sandstones and limestone. The
Oligocene to Quaternary volcanic-sedimentary suites of the
Sredinny Range and Southern Kamchatka terranes overlie the
Ganal series unconformably and are described in detail in
those sections. They include the Oligocene to Middle
Miocene Anavgay series, the Late Miocene to Early Pliocene
Alney series, the Pliocene Golyga suite and Quaternary
sequences. Generally, the rocks of the Ganal series are

exposed in the western half of the terrane while the middle

110

Figure 21 - Stratigraphy of the Canal terrane

112

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

 

 

 

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113
and late Tertiary rocks are found in the eastern part of
the terrane.

Metamorphic grade of the Ganal series varies from
epidote-amphibolite to greenschist facies, exemplified by
mineral assemblages found throughout the exposures of the
series (Herman et al., 1978; Tararin, 1977; Gnibidenko et
al., 1974). Mineral assemblages indicative of
epidote—amphibolite facies metamorphism include hornblende,
albite, quartz, and epidote. Some of the minerals of the
amphibole group are the result of high pressure
metamorphism, i.e., blueschist facies (Dobretsov and
Kuroda, 1970; Herman et al., 1978; Gnibidenko et al.,
1974). Mineral assemblages indicative of greenschist
facies metamorphism include albite, epidote, chlorite,
quartz, actinolite and biotite. Mineral assemblages of
both epidote-amphibolite and greenschist facies
metamorphism found in pelitic rocks include biotite,
garnet, cordierite, sillimanite, kyanite and staurolite.
These minerals are found in pelitic schist, gneisses and
marbles.

The age of the Ganal series is constrained only by
several K-Ar radiometric age dates. An upper age limit for
the series may be assigned as Oligocene, the age of the
unconformably overlying Sredinny Range volcanic arc
formations. A list of the radiometric and the rock type
from which they came is listed in Table 3. Eleven of the

dates obtained from granulite, gneiss and gabbro are

114

Table 3 — Potassium - argon radiometric dates from the
Ganal terane

115

Table 3

 

 

 

ROCK TYPES AGE (Ma)
granulites
hypersthene - biotite - garnet gneiss 188,283
biotite - hypersthene gneiss 172
plagiogranite 138
schist 120,121

Ganal Series

 

biotite gneiss 94,188

amphibolite 65,95,95

gneiss - 69,88

granite 65
gabbro

gabbro pegmatite 270,314

gabbro norite 93,283

cortlandite 234

116

scattered throughout the Phanerozoic, from Early
Pennsylvanian time to middle Early Cretaceous time and are
too varied to suggest a meaning for them. However, five
dates, four from the rocks of the Ganal series and one from
a gabbro-norite, average 93.2 i 2.9 Ma, a middle Cenomanian
age. In addition, three dates obtained solely from the
rocks of the Canal series average 66.3 i 1.9 Ma, at the
Late Cretaceous/Paleocene time boundary. Unfortunately
neither the location of the sample nor the sample types,
whether whole rock or mineral, are given in the reference.

Intrusive rocks found in the terrane are predominantly
gabbro-norites but also include diabase and plagiogra-
nites. The Yurchik Massif, a major intrusive body of
medium grained gabbro-norite, is surrounded by a
metamorphic contact aureole along which granulites,
consisting of biotite—garnet-cordierite-hypersthene-quartz
- plagioclase gneisses and hornfels that also contain
clinopyroxene and orthopyroxene, are found. The contact
aureole is a few meters up to 30 to 40 meters in width.
Grain size of the gabbro—norite pluton becomes fine towards
the margins and coarsens towards the center (Herman et al.,
1978). Tertiary intrusive rocks include diorite and
granodiorites of Miocene age (Krasny, 1964; Lebedev et al.,
1967).

The structural features of the Ganal terrane trend
northwest-southeast and parallels the contact with the

Eastern Ranges terrane. These features include folding,

117
metamorphic fabric and zones of shearing. The Ganal series
itself is intensely foliated and strongly schistose, and
accompanied by abundant zones of shearing and crushing
(Lebedev et al., 1967; Tararin, 1977). The contact with
the Eastern Ranges terrane is described as a thrust fault
along which intense foliation of the associated rocks and
mylonites are present (Herman et al., 1978). The thrust
plane dips southwest 40° to 50°, parallel to folds in the
Stenovaya series of the southern margin of the Eastern
Ranges terrane. The western margin of the terrane is the
narrow, southern extremity of the Central Kamchatka Basin,
commonly described as a graben in this region and bounded
by normal faults (Erlich, 1979). The southern margin of
the terrane is bounded by a large fault of undetermined
character exposed in the Nachikinsk anticline (Gnibidenko
et al., 1974). Across this fault lies the Southern
Kamchatka terrane.

On the basis of the available data, the basement of the
Canal terrane, the Ganal series, is suggested to represent
a portion of an oceanic layer of Early to middle Cretaceous
age, based on the upper age limit set by the middle
Cretaceous (Cenomanian) grouping of K-Ar age dates.
Metamorphism of the series into moderate and high grade
metamorphic schists occurred during two primary events.

The events are dated by the clustering of dates at 93 and
66 Ma, middle Cenomanian and latest Cretaceous/earliest

Tertiary time. The first event is related to the

118
intrusion of the majority of the gabbro-norites and
diabases found throughout the Canal series. A mechanism
for this event is unknown, but due to the suggested oceanic
character of the rocks, may be related to the formation of
the rocks at a ridge crest or hot spot volcanic center, or
subduction zone/island arc igneous activity. The second
event, a regional metamorphism (Tararin, 1977; Herman et
al., 1978), occurred in response to the accretion of the
Ganal and Eastern Ranges terranes. Compressive and shear
stresses applied to the Ganal series during the
accretionary episode resulted in intense shearing and
deformation of the rocks. This event also affected the
southern margin of the Eastern Ranges terrane producing the
metamorphic Stenovaya series.

Uplift and erosion of the Ganal terrane occurred during
Paleocene, Eocene and Oligocene time as evidenced by the
lack of formations of this age. Development of the middle
Tertiary Sredinny Range arc in Oligocene time led to the
eruption and deposition of volcanic and sedimentary
suites. Miocene igneous plutons in the Ganal terrane are
related to this period of arc activity. Volcanism and

sedimentation continued through Quaternary time.

SOUTHERN KAMCHATKA TERRANE

The southern part of Kamchatka Peninsula, bounded by
the Ganal terrane to the north and the Malkinsk and Kvakhon
terrane to the west, is the Southern Kamchatka terrane.
Late Cretaceous arc formations that overlie deep water
sediments are unconformably overlain by middle and late
Tertiary volcanic rocks (fig. 22). The Tertiary
stratigraphic column of the terrane is very similar to the
column of the Sredinny Range terrane and suggests the
possibility that these regions have been one continuous
feature since at least Oligocene time.

The basement of the terrane is indicated to be oceanic
crust by exposure of a deep water sedimentary sequence of
sandstones, siltstones and argillites with layers of tuffs,
siliceous shales, jasper and calcareous sandstone, that are
exposed in the northwest part of the terrane (Krasny, 1964;
Gnibidenko et al., 1974). Calc-alkaline volcanics of Late
Cretaceous age overlie the sedimentary sequence and are
exposed in the same region of the terrane (Herman et al.,
1978; Krasny, 1964). The volcanics are dated by fossil
remains of the mollusc Inoceramus Schmidti Mich., of
Santonian to Campanian age (Herman et al., 1978). Herman
et al. (1978) names the sequence the Iruney series.

Because the Iruney series is an oceanic layer in western
Kamchatka, the calc-alkaline arc formations of Late
Cretaceous age in the Southern Kamchatka terrane are more

properly correlated with either the Kirganik or Khapitsk
119

120

Figure 22 - Stratigraphy of the Southern Kamchatka terrane

 

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122
suites of the Sredinny Range and Eastern Ranges terranes,
respectively.

Tertiary sequences are exposed throughout the terrane
in contrast to the limited outcrops of Late Cretaceous
rocks. The Anavgay series unconformably overlies the older
formations and can be divided into three separate suites.
The Vilyucha suite is of Late Oligocene to Early Miocene
age and consists of sandstones, argillites and
conglomerates, sometimes interbedded in a flysch—like
manner, with layers of tuffs in the upper part of the
suite. The base of the suite is not exposed but its
visible thickness is 2500 meters (Aprelkov, 1971). Pebbles
found in the conglomerates consist of fragments of
greenschists, phyllites and granites and are erosional
remnants of the Canal terrane (Aprelkov, 1971). The
Paratun suite, about 2200 meters thick, unconformably
overlies the Vilyucha suite and consists of basalt,
andesite and dacite flows alternating with beds of tuff and
tuffaceous sandstones and conglomerates. Again, the
pebbles of the conglomerates commonly consist of fragments
of greenschists, phyllites and granites. The Middle
Miocene Berezovsk suite, the uppermost suite of the Anavgay
series, unconformably overlies the Vilyucha suite and is
about 1500 meters thick. The suite consists of dacitic and
andesitic pyroclastics with subordinate amounts of
sandstone and siltstones. Abundant faunal remains date

each of the suites of the series. The Late Miocene to

123
Pliocene Alney series unconformably overlies the Anavgay
series and is represented by basalts, andesites and their
associated pyroclastics. Acidic (felsic) volcanics are
common in the upper part of the suite. The suite is dated
by floral and faunal remains and has an observed thickness
of up to 1500 meters. The unconformably overlying Golyga
suite conists of ignimbrites and tuffs, up to 300 meters
thick. Radiometric age dates of the volcanics range from
to 12 Ma (Aprelkov, 1971), Late Miocene to Pliocene age.
Quaternary volcanic deposits complete the stratigraphy of
the Southern Kamchatka terrane and consist of basalts,
andesites, dacites and associated pyroclastics.

The structural features of the terrane trend in two
primary directions. The Nachikinsk anticline, located in
the northern part of the terrane along the boundary with
the Canal terrane, contains numerous faults and folds
trending northwest to southeast, parallel to the Southern
Kamchatka/Ganal boundary zone (Aprelkov, 1971). Along the
eastern margin of the terrane, structural features of the
South Kamchatka anticlinorium trend in a northeasterly
direction, parallel to the coastline and the Kuril-
Kamchatka trench (Aprelkov, 1971).

Dioritic and granodioritic plutons of Miocene age and
granitic plutions of Miocene and Pliocene age are
widespread in the northern, central and eastern regions of

the terrane (Aprelkov, 1971; Krasny, 1964). They intrude

124
the Oligocene and Miocene formations, primarily the Anavgay
series.

The northern boundary of the Southern Kamchatka
terrane, the Nachikinsk anticline, contains a major fault
zone, across which lies the Ganal terrane. The zone
extends southeast and reaches the coast south of the Avacha
Inlet. To the northwest, the fault separates the high
grade metamorphic rocks of the Ganal series from the Late
Cretaceous calc-alkaline volcanics and is described as a
normal fault (Herman et al., 1978). The western margin of
the terrane is a narrow basin, the Golyga trough, that
trends northeast and is filled with 5000 to 6000 meters of
Late Paleogene to Quaternary volcanic and clastic sequences
(Smirnov, 1971). The trough continues south into the Sea
of Okhotsk (Gnibidenko and Khvedchuk, 1982) and may
possibly extend north to connect with the trough located
along the western margin of the Central Kamchatka Basin.
West of the trough lies the Kvakhon terrane.

The northwestern margin of the terrane is the southern
extension of the Central Kamchatka Basin, in this region, a
normal faulted graben feature across which lies the
metamorphic complex of the Malkinsk terrane. Although no
direct evidence of a major fault zone is found along the
western margin of the Southern Kamchatka terrane, the
existence of a suture/boundary zone may be inferred from
the contrasting rock types found on the opposite sides of

the Central Kamchatka Basin.

125

The development of the Southern Kamchatka terrane
commenced with the deposition of deepwater sediments of
Late Cretaceous age possibly on oceanic crust, and are
overlain by formations of a Late Cretaceous arc. The
presence of the arc formations of the same age in the
Sredinny Range, Eastern Ranges and Southern Kamchatka
terranes indicates that either the Iruney or Eastern Ranges
arcs extended into the region of Southern Kamchatka. Lack
of Paleocene and Eocene formations in the terrane are the
result of a period of Early Tertiary uplift. Transgression
and development of the Oligocene to Miocene arc formations
were contemporaneous with the development of the Sredinny
Range volcanic arc and indicates the continuity between
these regions. In addition, the arc volcanics of this
period and their related intrusives are also found in the
Canal terrane and the southern area of the Eastern Ranges
terrane. Volcanic activity in the Southern Kamchatka

terrane continued through Quaternary time.

CAPE KAMCHATKA TERRANE

The Cape Kamchatka terrane is a Late Cretaceous or
Early Tertiary oceanic sequence overlain by Tertiary
volcanic and sedimentary sequences (fig. 23). A Late
Cretaceous ophiolite suite is thrust over the southern
margin of the cape and may represent a fragment of the
basement of the terrane. Structural and stratigraphic data
indicate the Cape Kamchatka terrane is distinct from the
Eastern ranges terrane but is continuous with the
Komandorskie Islands of the western Aleutian Island arc.

Cape Kamchatka may be divided into separate northern
and southern geological provinces. Exposed in the northern
two—thirds of the terrane is the Stolbovsk series that
includes, from bottom to top, the Tarkhovsk, Vereschchagin,
Rifovsk and Baklanov suites (Markov et al., 1969). The
Tarkhovsk suite consists of pillow basalts, tuffs and
cherts and tuffaceous and siliceous argillites, with a
thickness of 1300 to 1600 meters. Lack of paleontological
data on the suite prevents an accurate age estimate but,
the Paleocene age of the conformably overlying Vereshchagin
suite suggests a Late Cretaceous or Paleocene age for the
Tarkhovsk suite. The Vereshchagin suite consists of
alternating coarse and fine clastics with conglomerates and
pyroclastic material. Siliceous tuffs are found at the
base of the suite. The suite is up to 4000 meters thick
and is dated as Paleocene to Eocene on the basis flora and

fauna found at the top of the section. The conformably
126

127

Figure 23 - Stratigraphy of the Cape Kamchatka terrane

LATE

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NEOGENE

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128

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129
overlying Rifovsk suite, 2000 to 3000 meters thick,
contains fine to medium grained clastics, marls, tuffs and
coal. A basal conglomerate reaches a thickness of 320
meters in the northern regions of the cape. Faunal remains
date the suite as Early Eocene (Mironoba, 1982) or Late
Eocene to Early Oligocene (Markov et al., 1969). The
Baklanov suite consists of abundant volcanic rocks with
layers of elastic and carbonate rocks. The suite is up to
3000 meters thick and is dated by faunal remains of Middle
to Late Eocene (Mironoba, 1982) or Oligocene (Markov et
al., 1969) age. The volcanic material of the Vereshchagin,
Rifovsk and Baklanov suites are generally coarser and
thicker towards the northern region of Cape Kamchatka and
include both basaltic and andesitic types (Markov et al.,
1969; Krasny, 1964). Early to Middle Miocene rocks consist
of conglomerates, sandstones, siltstones and argillites
with tuffaceous layers. Late Miocene to Pliocene rocks
consists of conglomerates, sandstones and argillites.
Quaternary rocks consist of fluvial and lake deposits and
are entirely devoid of volcanic material. The Neogene and
Quaternary sequences are thin and separated by numerous
unconformities (Markov et al., 1969).

Exposed in the southern one-third of the terrane is an
ophiolite sequence with overlying sedimentary rocks. The
lower section of the suite includes dunites, gabbros and
serpentinites overlain by gabbros and pillow basalts that

are extensively intruded by gabbro and diabase dikes

130
(Markov et al., 1972). Serpentinites and serpentinization
of the ultramafics is common. The upper section of the
ophiolite suite is named the Afrika series and is divided
into the Smaga and Pikezh suites (Khotin, 1972). The Smaga
suite, approximately 1400 meters thick, consists of
argillaceous and silty tuffs with layers and lenses of
cherts, carbonates and basalts, spilites and tuffs. The
Pikezh suite may be subdivided into two subsuites with
differing character. The lower subsuite, 400 meters thick,
conformably overlies the Smaga suite and includes
tuffaceous and siliceous clastics with lenses of chert and
clastics. The upper subsuite, 400 meters thick, is
represented by fine and medium grained sandstones with
interbeds of black mudstone. Foraminifera from carbonate
rocks of the Afrika series and spores and pollen from the
Pikezh suite indicate a Late Cretaceous age for the series
and a Cretaceous age for the underlying ophiolite
sequence. Tertiary sequences in the southern region of the
terrane consist only of Miocene, Pliocene and Quaternary
rocks of the same composition of the contemporaneous
deposits of the northern part of the terrane. Paleocene
through Oligocene aged rocks are absent.

The Pikezh fault zone separates the terrane in its
northern and southern provinces. The zone is seven to
eight kilometers wide on the southeast coast of the cape,
where it is identified geologically, but narrows to a width

of a few hundred meters to the northwest. The zone

131
continues northwest to the Ust-Kamchatka fault zone and is
identified by a linear zone of geophysical anomalies. A
small outcrop of ultramafics and gabbros exposed on the
northwest shoreline of Lake Nerpich'ye is suggested to be
related to the fault zone. Crushed, highly altered rocks
with a blue fault gouge and serpentinite inclusions are
found where the Pikezh fault zone is exposed.

Structurally, the southern and northern portions of the
cape differ markedly. In the southern region, several
thrust faults are found amongst the rocks of the ophiolite
suite and the Afrika series. The faults strike northwest
and vary in dip from 25° to nearly vertical. The fault
zones are 20 to 30 meters wide containing deformed, crushed
and altered rocks and blocks of serpentinized ultramafics.
Structural trends in the northern part of the terrane trend
generally in the same direction, northwest, but the degree
and intensity of faulting is less. Two reverse faults are
present that have planes dipping to the southwest.
Strike-slip faults of both left and right lateral motion
are common. Some fault planes are associated with gabbro
and gabbro—diabase dikes up to 3 meters in width. Strikes
of folds follow the northwest trends of the fault zones.

Radiometric age dates from the cape include a K—Ar (?)
date of 36 Ma (Early Oligocene) from a gabbroic dike found
in the northern part of the peninsula. Three dates form
the ophiolite exposure averaging 900 Ma were obtained by

using the K-Ar method (Vysotsky and Gracheva, 1981) and are

132
considered to be unreliable due to the Late Cretaceous age
of the deepwater sediments overlying the suite.

The western margin of the terrane is the Eastern
Kamchatka Basin (fig. 25), an accretionary wedge cut by
thrust faults (see Eastern Kamchatka basin section). The
basin and the major thrust fault associated with it, the
Grechishkin thrust, extend from southwestern Kronotsky
Peninsula north into the Komandorsky Basin of the Bering
Sea. The basin separates the Cape Kamchatka and Kronotsky
terranes from the Eastern Ranges terrane. The terrane is
bounded on the north by the Bering Sea and on the south by
the Pacific Ocean.

The development of the Cape Kamchatka terrane commenced
in Late Cretaceous or Early Tertiary time with the
formation of the oceanic crust exposed in the terrane. The
age of the oceanic basement of the northern block,
represented by the Tarkhovsk suite, is Late Cretaceous or
Paleocene, and is not too different from the Late
Cretaceous age of the Afrika series. Therefore, it is
difficult to determine whether the ophiolite exposure of
the southern part of the terrane is allochthonous in the
sense that it had a completely different place of origin
than the oceanic crust of the northern block or if it is
allochthonous in the sense that it is an uplifted block of
the oceanic crust of the northern block. If it is truly
allochthonous, it may be considered an individual terrane

but lack of data precludes this determination. Time of

133
uplift (or acretion) of the block cannot be constrained.
However, such an event may lead to the deposition of
abundant conglomerates, such as is observed at the base of
the Early Eocene Rifovsk suite.

Volcanic activity and sedimentation of the terrane
continued throughout Paleocene and Eocene time and was
followed by a Late Eocene or Early Oligocene to Late
Oligocene hiatus. Intrusion of gabbroic dikes occurred
towards the beginning of this period in Early Oligocene
time. Minor clastic sedimentation resumed in Miocene time

and continued through Quaternary time.

KRONOTSKY TERRANE

The stratigraphy of the Kronotsky terrane consists of

Late Cretaceous to Oligocene high alumina tholeiitic and
alkaline basalts indicative of an island arc overlain by
middle and late Tertiary sedimentary sequences (fig. 24).
The Cape Kamenistyy suite lies at the base of the
terrane and consists of layers of basalts, tuffs and
tuffaceous clastics with less common andesite and
andesite—basalt volcanics (Pushcharovskiy et al., 1983;
Sadreev and Dolmatov, 1965). The suite is broken into
lower and upper slabs by large thrust faults. Siliceous
tuffs of the lower slab contain Coniacian and Campanian
radiolaria while the upper slab contains Maastrichtian to
Early Paleocene radiolaria (Pushcharovskiy et al., 1983).
The basalts are high alumina tholeiitic basalts commonly
found in island arcs (Pushcharovskiy et al., 1983). A
serpentinite melange made up of harzburgites, wehrlites,
lherzolite, amphibolites, gabbro-norites and gabbros is
found along the fault planes and be ophiolite fragments.
Unconformably overlying the Cape Kamenistyy suite is the
Kronotsky series, divided into the Kubovsk and Kozlovsk
suites. The Kubovsk suite is further subdivided into lower
and upper subsuites. The lower subsuite consists of
basalts, tuffs and tuffaceous and calcareous clastics with
layers of chert and has a thickness of 1300 meters. Faunal
remains of foraminifera, radiolarians and mollusks are

Paleocene to Early Eocene age. The upper subsuite consists

134

135

Figure 24 - Stratigraphy of the Kronotsky terrane

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137
of basalts, tuffs and tuffaceous clastics containing chert
and carbonate layers and has a thickness of 1600 meters.
Faunal remains are lacking but an Eocene to Early Oligocene
age is inferred from the ages of the overlying and
underlying suites. The Kozlovsk suite, the upper part of
the Kronotsky series, overlies the Kubovsk suite with a
minor unconformity and consists of pillow basalts, tuffs
and tuffaceous clastics with a thickness of 1400 meters.
Alkali basalt flows are found at the top of the Kozlovsk
suite (Suprunenko and Markovskiy, 1973). Remains of
mollusks of Late Oligocene age found in elastic material at
the top of the section date the suite. Examination of the
chemistry of the basalts of the Kronotsky series indicate
their similarity to high alumina island arc basalts (Rotman
and Markovskiy, 1968; Suprunenko, 1972; Suprunenko and
Markovskiy, 1973). Dikes of gabbro and diabase intrude the
Kronotsky series and are, most likely, old feeder channels
for the extensive basalt flows found throughout the series
(Sadreev and Dolmatov, 1965). In addition, the number of
basalt flows increases from the bottom to the top of the
section.

Unconformably and transgressively overlying the
volcanic formations of the Kronotsky series is the
Rakitinsk suite of Early Miocene age. The suite consists
of sandstones, siltstones with chert layers, argillite,
tuff and conglomerate. Unconformably overlying the

Rakitinsk suite is the Early to Middle Miocene Tyushevka

138
series that includes the Tat'yana, Konusnaya, Olenin and
Valentinovsk suites (Mironoba, 1982). In the Kronotsky
terrane, the Tyushevka series is found in a narrow basin
trending generally north-south that is bounded by outcrops
of the Kronotsky series and Rakitinsk suite on the east and
by the Grechishkin overthrust belt to the west. The basin
extends from southwest of Kronotsky Peninsula to northwest
of Cape Kamchatka. The overthrust belt separates the
Kronotsky and Cape Kamchatka terranes from the East
Kamchatka Basin.

The lower portion of the Tat'yana suite is
predominantly sandstones and gravelites, with a thickness
of 1700 meters. The upper section of the suite is a flysch
sequence consisting of interbedded sandstones and
argillites with a thickness of 3000 meters. The lower and
upper sections of the Tat'yana suite are synonymous with
the Tundrovsk and Talovsk suites, respectively (Mironoba,
1982). The interbedded sandstones and argillites of the
Konusnaya suite have a thickness of 1200 meters and
conformably overlies the Tat'yana suite. The Olenin suite
is conformable on the Konusnaya suite and consists of a
rhythmic alternation of sandstone and siltstone, with
lesser amounts of argillite and tuff and a thickness that
varies from 200 to 1700 meters. The Valentinovsk suite,
the uppermost suite of the Tyushevka series consists of a
lower section of sandstones, 50 meters thick and an upper

section of argillite and diatomite, 140 meters thick. A

139

major unconformity separates the Tyushevka series from the
overlying, faunally dated Kavran series, of Late Miocene to
Pliocene age. The Kavran series consists of 500 meters of
argillites, conglomerates, sandstones sometimes interbedded
with lignites and tuff-breccias. Quaternary andesites,
andesite-basalts, basalts and their associted tuffs
complete the stratigraphic column of the Kronotsky terrane.

The bedding of the Kronotsky series and Rakitinsk suite
dips northwest 5 to 20 degrees in a monoclinal fashion.
Folds present are described as gentle but sometimes the
limbs dip 40 to 50 degrees when located near faults
(Shapiro and Seliverstov, 1975). Deformation of the
Tyushevka series is more intense, due to the proximity of
the exposures to the Grechishkin overthrust. Folds trend
northeast with their northwestern limbs dipping 30° to 35°
while the southeastern limbs have very steep dips or are
vertical. The folds are cut by reverse faults with beds
commonly overturned in the vicinity of the overthrust. In
contrast, the Late Miocene and Pliocene formations are
undeformed and horizontal (Shapiro and Seliverstov, 1975).

The regional extent of the Kronotsky terrane is
difficult to determine. Outcrops of blocks of basaltic
material found near the Tret'ya River mouth on the
Kamchatka Bay (fig. 2) in close proximity to the
Grechishkin overthrust zone are similar to the Kronotsky
basalts (Shapiro, 1980). In addition, clasts of basaltic

rocks found in the Tyushevka series in the same area are

140
also similar to the Kronotsky basalts. It is possible,
then, that the rocks of the terrane extend into this region
of the Kamchatka Bay. Geophysical data indicate a similar
situation (fig. 18 and 26). These data delineate the
Grechishkin thrust as a line separating low gravity (A g)
and magnetic (ALTa) anomalies on the west from high gravity
and magnetic anomalies on the east (Suprunenko, 1971). The
trace coincides with the geological exposure of the thrust
zone from Cape Kamchatka to just south of Kronotsky
Peninsula, but then veers sharply southeast and narrow
moving into Kronotsky Bay and into the Pacific Ocean. To
the north of Kronotsky Peninsula, the anomalies narrow up
to the vicinity of Cape Kamchatka. The western boundary of
the anomalies closely follows the coastline in the
Kamchatka Bay and thus, the trace of the Grechishkin thrust
belt. Therefore, assuming the geophysical anomalies
outline the mafic volcanic rocks of the Kronotsky series,
these data provide an approximation to the extent of the
Kronotsky terrane.

The tectonic evolution of the Kronotsky terrane
commenced in Late Cretaceous time with the eruption and
deposition of the Cape Kamenistyy suite. Basalts of the
suite are high alumina island arc basalts similar to the
overlying high alumina island arc basalts. The thrust
faulted structure of the Cape Kamenistyy suite suggests the
possibility that the suite, or the overlying Kronotsky

series, may be allochthonous.

141

Volcanic activity of the Kronotsky series lasted from
Paleocene to Oligocene time. Clastic layers in the series
indicate the rocks may have been above sea level and
subjected to erosion. Based on the geochemistry of the
basalts of the Kronotsky series, they represent high
alumina basalts of the type found in island arcs. Magnetic
anomalies outline the boundary of the Kronotsky series.
Volcanic activity ceased in Oligocene time and was followed
by a hiatus until Early Miocene time, when deposition of
the Rakitinsk and Tyushevka series occurred. A Middle
Miocene period of orogeny and uplift is indicated by the
deformation of the Tyushevka series and angular
unconformity separating the Tyushevka series from the
undeformed and horizontal overlying Late Miocene and
Pliocene deposits. The basin in which the Tyushevka series
was deposited and the major unconformity that separates
Early and Late Miocene rocks are the results of the
accretion of the Kronotsky and Eastern Ranges terrane in
Middle Miocene time. The Tyushevka trough is proposed to
be an inter-terrane basin that formed and filled in with
sedimentary rocks during the approach and accretion of the

two terranes.

EASTERN KAMCHATKA BASIN

The Eastern Kamchatka Basin lies between the Eastern

Ranges terrane on the west and the Kronotsky and Cape
Kamchatka terranes on the east (fig. 20). The basin
contains a thick, highly deformed sedimentary sequence of
Oligocene and younger age resembling an accretionary wedge
(fig. 25). The Grechishkin overthrust zone is located
along the eastern margin of the basin.

The oldest sequence of the basin consists of fine to
coarse Clastic sediments containing some tuff (Mironoba,
1982). Several names have been proposed for this
formation including the Tundrovsk suite (Shapiro and
Seliverstov, 1975), the Drozdovsk and Stanislavsk suites
(Suprunenko, 1977) and the Bogachevka series (Fedynskiy and
Levin, 1970). The name Bogachevka series will be adopted
in this paper due to its predominance in the Soviet
literature.

The age of the Bogachevka series is unknown but is
suggested to be Oligocene to Early Miocene (Shapiro and
Seliverstov, 1975). Paleontological remains are sparse or
absent. The Chazhmin suite unconformably overlies the
western exposures of the Bogachevka series and consists of
argillite, siltstone, sandstone, chert and tuff and is 2500
meters thick. Faunal remains of Early Miocene age date the
suite. The Early to Middle Miocene Tyushevka series

unconformably overlies the Chazhmin suite and includes each

142

143

Figure 25 - Stratigraphy of the Eastern Kamchatka Basin

   

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145
of the previously described suites except for the
Valentinovskaya suite (Mironoba, 1982; Shapiro and
Seliverstov, 1975). Late Miocene and Pliocene clastic
Kavran series and Quaternary volcanics and clastics
complete the stratigraphy of the Eastern Kamchatka Basin.

The structure of the eastern Kamchatka Basin is very
complicated. Each formation of the basin up to and
including the Middle Miocene suites of the Tyushevka series
are cut by numerous imbricate reverse and thrust faults,
the easternmost of the thrusts being the Grechishkin
overthrust zone (fig. 20). The fault planes dip northwest
20 to 35 degrees. Folds in the basin trend northeast and
are sometimes overturned to the southeast. The Grechishkin
overthrust zone itself is a consecutive series of reverse
faults and overthrusts that override and truncate one
another. Dips of the faults are generally 20 to 35 degrees
but sometimes are steeper. Thus, based on the lithology of
the rocks in the basin and their structural characteris-
tics, the basin an accretionary wedge.

As previously mentioned, the Eastern Kamchatka Basin
extends from southeast of Kronotsky Peninsula to north of
Cape Kamchatka. From Oligocene to Middle Miocene time, the
activity in this zone included continuous accumulation and
deformation of the predominantly clastic suites. Orogenic
activity ceased in Middle or Late Miocene time and was
followed by a quiet period of Late Miocene to Pliocene

sedimentation.

146

The period of activity of the accumulation and
deformation of the rocks in the basin, an accretionary
wedge, correlates with the period of activity of the Middle
Tertiary Sredinny Range volcanic arc and is proposed to
locate the site of the trench associated with the arc. The
Middle Miocene unconformity and the following period of no
tectonic activity is the result of the accretion of the
Kronotsky terrane to the Eastern Ranges in Middle Miocene
time. The ensuing Quaternary volcanic activity found
throughout Eastern Kamchatka is the result of the
development of the present day Kuril—Kamchatka subduction

zone.

147

Figure 26 - Gravity anomaly map of Kamchatka Peninsula
(after Gnibidenko et al., 1974)

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39V

GEOLOGIC RELATIONS OF KAMCHATKA PENINSULA
WITH THE KURIL AND ALEUTIAN ISLAND ARCS

Geologic data on the Kuril Island arc, extending from
the southern tip of Kamchatka Peninsula, south to Hokkaido,
and the Komandorskie Islands of the western Aleutian arc,
located east of Cape Kamchatka, suggest these features are
related tectonically to terranes of Kamchatka Peninsula.

The Kuril Islands may be divided into two separate
island chains referred to as the Lesser and Greater Kuril
Islands. Islands of the Lesser Kuirles are found only in
the southern part of the island chain, just north of
Hokkaido (fig. 3) but continues to the north as the
submerged Vityaz Rise (Savostin et al., 1983; Gnibidenko et
al., 1983). The stratigraphy of the islands include Late
Cretaceous (Campanian) to Early Tertiary andesites,
basalts, conglomerates, argillites and siltstone with
layers of sandstone, Oligocene to Miocene sandstones,
siltstone, argillites and volcanics and Pliocene to
Quaternary andesite and basalt volcanics (Savostin et al.,
1983; Markov and Khotin, 1973; Krasny, 1964). An
unconformity separates the Early and Middle Tertiary
rocks. Outcrops of spilite, diabase and gabbro at the base
of the Late Cretaceous rocks (Krasny, 1964; Gnibidenko et
al., 1983) indicates the presence of a Cretaceous oceanic
layer underlying the Lesser Kuril Islands. A similar
sequence of rocks is exposed in Eastern Hokkaido, the

southern end of the Lesser Kurils (Kimura and Tamaki, in

151

152
press). The major unconformity between early and late
Paleogene rocks on Hokkaido led Kimura and Tamaki (in
press) to suggest the Kula-Pacific ridge subducted there in
Early Tertiary time.

No rocks older than Oligocene age are exposed in the
Greater Kuril Islands. The stratigraphic column includes
Late Oligocene to Early Miocene andesites, basalts, cherts,
conglomerates and sandstones, Middle to Late Miocene tuffs
and clastics, Pliocene tuffs, conglomerates, dacites,
andesites and basalts and Quaternary basalts and andesites
(Belyy, 1974; Krasny, 1964; Savostin et al., 1983; Markov
and Khotin, 1973). A similar sequence is also exposed on
eastern Hokkaido (Kimura and Tamaki, in press).

In general, the stratigraphy of the Kuril Islands may
be correlated with geology of certain terranes of
Kamchatka. The Lesser Kuriles, although not physically
connected to Kamchatka, is geologically very similar to the
Eastern Ranges terrane. Both regions are characterized by
a period of Late Cretaceous to earliest Tertiary island arc
volcanism, a Paleocene to Oligocene hiatus and Miocene to
Quaternary volcanics and clastics. The period of Late
Cretaceous volcanism of these regions also correlates with
the period of activity of the Iruney arc, facies of which
are found in the Sredinny Range terrane.

The Oligocene to Miocene formations of the Greater
Kuril Islands are very similar to contemporaneous deposits

found in the Sredinny Range and Southern Kamchatka terranes

153

and suggests a continuous volcanic arc extended through
central and southern Kamchatka and into the Kuril Islands
during this time. From Pliocene to Quaternary time, the
stratigraphy of the Greater Kuril Islands is very similar
to contemporaneous formations found in the Eastern Ranges
and Southern Kamchatka terranes suggesting a continuous
volcanic arc extended through eastern and southern
Kamchatka and into the Kuril Islands at this time.

Several authors (e.g. Markov et al., 1969; Vlasov et
al., 1965) have linked Cape Kamchatka with the Komandorskie
Islands of the western Aleutian Island arc. The
stratigraphy of the Komandorskie Islands includes Late
Paleocene to Eocene pillow basalts, pelitic and silty
tuffs, tuffaceous clastics, argillite, chert, jasper and
limestone, Late Oligocene to Early Miocene tuffs,
andesites, basalts, tuffaceous clastics and coal, and
Pliocene tuff, clastics, andesites, dacites, and basalts
(Shmidt, 1978; Krasny, 1964). The basement rocks of the
Early Tertiary rocks resembles the top of an oceanic layer
(Shmidt, 1974). In addition, the structural trend of the
islands is northwest, parallel to the trend of the Aleutian
arc in this region.

The comparison of the geology of the Komandorskie
Islands with Cape Kamchatka demonstrates their similarity.
Both areas are characterized by a Late Cretaceous or Early
Tertiary oceanic basement overlain by middle and Late

Tertiary volcanic arc facies. Dating of the older

154
formations of both terranes is tentative (Markov et al.,
1969; Shmidt, 1978) but the general geologic characteris—

tics are very similar and it is therefore possible to

suggest these two areas were one continuous volcanic arc
during Tertiary time that developed on oceanic crust.
Geological similarities exist between the Sredinny
Range terrane and the Academy of Sciences Rise and the
Lebed Swell located in the Sea of Okhotsk. Rocks dredged
from these features include granite, granodiorite,
andesite, rhyolite and biotite schist of middle to Late
Cretaceous age as determined by K-Ar radiometric age
determinations (Burk and Gnibidenko, 1977). These rocks
and their ages are indicative of a Late Cretaceous island
arc system that may have been continuous with the Late
Cretaceous Iruney arc of the Sredinny Range terrane

(Savostin et al., 1983).

PLATE MOTIONS

The relationship between tectonic events, such as
island arc andesitic volcanism, orogenic uplift, ophiolite
emplacement, etc., and the characteristics of motion of
oceanic crustal plates, i.e., direction and velocity, that
determine angles of convergence between the oceanic plates
and a particular region, has been demonstrated for many
areas in the Circum-Pacific region (e.g., Wallace and
Engebretson, 1984; Engebretson et al., 1984; Henderson et
al., 1984; Page and Engebretson, 1984; and others).
Comparison of the postulated tectonic events of Kamchatka
Peninsula with plate motion data from Engebretson (1982)
indicates several tentative relationships. Examination of
the location of the plate boundaries (figs. 29 through 34)
with respect to the relative motion of the plates (fig. 28)
since the end of the Jurassic period, the approximate time
of the initiation and development of the terranes of
Kamchatka, indicate that the Izanagi, Farallon, Kula and
Pacific plates interacted with Kamchatka during Cretaceous
and Tertiary time. Specifically, the relative motion
vector data were determined at 165° E longitude, 65° N
latitude, located north of Kamchatka in northeast Siberia.
Due to the proximity of this point with Kamchatka, it will
be assumed that the relative motion data are valid also for
the region of Kamchatka Peninsula.

Four different oceanic plates interacted with the

region of Kamchatka Peninsula during Mesozoic and Cenozoic

155

156

Figure 28 - Plate motion data of the Farallon, Izanagi,
Kula and Pacific plates showing direction
only. Shoreline of Kamchatka parallels the
north arrow (from Engebretson, 1982)

157

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158
time. They are, in order of appearance, the Farallon,
Izanagi, Kula and Pacific plates. There are five different
time periods during which these plates may have interacted
with Kamchatka (table 4). During three of the time
periods, interaction between Kamchatka and a single plate
occurred while during two transitional periods, both ending
with major plate reorganizations, it is difficult to
determine which of two plates interacted with Kamchatka due
to a lack of data on the location of plate boundaries
during these time periods.

The direction of motion of the four oceanic plates with
respect to Kamchatka since the beginning of the Late
Jurassic (fig. 28) and the characteristics of the major
plate reorganizations are as follows. From 165 to 115 Ma,
the Farallon plate was located in the vicinity of
Kamchatka. At the beginning of this period, the plate was
moving generally northeast with respect to Kamchatka but
from 145 to 135 Ma, the direction of motion changed from
N46°E to N348°E, a more north-northwest direction. A
northwesterly direction of motion was maintained through
119 Ma, the direction at 127 Ma being N355°E and at 119 Ma,
N317°E. From 119 to 115 Ma, the direction changed from
northwest to N37°E, northeast, and from 115 to 100 Ma, the
direction changed back to N307°E, northwest.

Around 100 Ma, the Farallon/Izanagi ridge passed
through the vicinity of Kamchatka and interaction of the

Farallon plate with Kamchatka ceased and interaction

159

 

 

Table 4 - Correlations between tectonic events of Kamchatka
Peninsula and relative motions of oceanic plates

160

 

 

 

 

 

 

 

 

 

 

 

 

  

 

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161

between the Izanagi plate and Kamchatka commenced. The
exact time of the event cannot be determined without a more
precise estimate of location of the Farallon/Izanagi ridge
and of the location of the middle Cretaceous Kamchatka
Peninsula. Because of this uncertainty, the motion vector
data for the Izanagi plate will be presented starting at
115 Ma, overlapping the Farallon motion vector data to
allow for the error in the location of the two regions.
Generally, the Izanagi plate moved north with respect to
northeast Siberia with the plate motion being N30°E at 115
Ma, N6°E at 100 Ma and N359°E at 95 Ma. From 165 to 95 Ma,
it is possible that a triple junction existed where the
Izanagi/Farallon ridge intersected the Eurasian coastline.
The motion data suggest convergence between the Farallon
plate and Eurasia occurred north of the triple junction
while transcurrent motion between the Izanagi plate and
Eurasia occurred south of the triple junction. In
addition, the position of the point, as indicated by the
position of the Izanagi/Farallon ridge crest, would have
been far south of northeast Siberia in Jurassic time but
migrated north in Jurassic and Early Cretaceous time.

Around 90 Ma, the first major plate reorganization
occurred. The Izanagi/Farallon ridge, trending
approximately north/south at this time, ceased spreading.
A new spreading center, the Kula/Farallon ridge, formed in
the eastern region of the Pacific Basin, adjacent to North

America. The reorganization split the Farallon plate into

162

two parts, with the southern portion remaining as the
Farallon plate and the northern half, in addition to the
entire Izanagi plate, becoming an enlarged Kula plate. The
Kula plate thus extended across the northern half of the
basin while the Pacific plate occupied the southwestern
area and the Farallon plate occupied the southeastern area
of the basin. The reorganization changed the direction of
motion of the Kula plate, which was the Izanagi plate, to a
more northwesterly direction. At 85 Ma, the Kula plate was
moving N293°E, to the northwest. Very consistent
northwesterly convergence continued through 48Ma, ranging
from N307°E to N325°E

Around 60 Ma, the Kula/Pacific spreading center entered
into the vicinity of the Early Tertiary Kamchatka
Peninsula. From 66 to 53 Ma, the direction of motion of
the Pacific plate changed from N333°E to N17°E and from 53
to 48 Ma, changed direction of motion to N357°E. During
this time period, from around 60 to 45 Ma, it is difficult
to determine which plate interacted with Kamchatka due to
imprecise knowledge of the location of the Kula/Pacific
spreading ridge and the location of Early Tertiary
Kamchatka Peninsula.

The second major plate reorganization occurred around
45 Ma and involved the cessation of activity of the Kula/
Pacific ridge and the formation of an enlarged Pacific
plate that included the unsubducted remainder of the Kula

plate. The Pacific plate thus occupied the western and

163
central regions of the basin while the Farallon plate was
located only along the North and South American coasts.
The Pacific/Farallon ridge trended north/south. The
reorganization was accompanied by a major change in the
direction of motion of the Pacific plate, from N357°E at 48
Ma to N325°E at 43 Ma. The change in motion from north to
northwest is indicated by the change in the trend of the
Hawaiian/Emperor seamount chain. Northwesterly motion of
the Pacific plate has continued from 43 Ma to the present,
with the direction consistently ranging from N293°E to
N305°E.

A correlation can be made between the periods of
northwesterly motion of the oceanic plates, corresponding
to convergence towards northeastern Siberia and Kamchatka
Peninsula, and periods of volcanic arc activity on
Kamchatka. Periods of no volcanic activity on Kamchatka
may either be related to no subduction activity, i.e., a
passive, transcurrent margin separating Kamchatka and the
oceanic plate, or to the subduction of a ridge crest.
Ridge crest subduction has been suggested to reduce or
completely eliminatevolcanic arc activity in the Kuril
Islands in Early Tertiary time (Kimura and Tamaki, in
press) and in the Aleutian Islands in Middle Tertiary time
(Delong et al., 1978). These periods are also accompanied
by uplift and erosion.

The Kvakhon/Omgon arc is proposed to have originated in

response to a shift in the direction of motion of the

164

Farallon plate around 165 Ma, the beginning of the Late
Jurassic epoch. The proposal is based on the fact that the
Farallon plate was in the vicinity of northeast Siberia at
this time and would have been responsible for any volcanic
arc activity in the region. Convergence towards northeast
Siberia persisted until around 110 Ma, when the
Farallon/Izanagi ridge passed through the vicinity of
Kamchatka causing interaction of the Farallon plate with
Kamchatka to cease and interaction of the Izanagi plate
with Kamchatka to begin. This period was one of
transcurrent motion between the Izanagi plate and
Kamchatka, an idea based on the northerly direction of
motion of the Izanagi plate, the lack of volcanics of
middle Cretaceous age on Kamchatka and the period of middle
Cretaceous sedimentation. Around 90 Ma, convergence
between the reorganized Kula plate and Kamchatka began and
resulted in the formation of the Iruney arc of the Sredinny
Range terrane and the Eastern ranges are of the Eastern
Ranges terrane. The two arcs may have formed along
transform faults found on the former Izanagi plate that
trended in a general north-south direction. The fracture
zones provided zones of weakness along which convergent
margins could form (Hilde et al., 1977) and led to a
situation that is similar to the present day Phillippine
Sea arc system.

Northwesterly motion of the Kula plate continued

through Paleocene and Eocene time. However, volcanism of

165
the Iruney and Khapitsk arcs had ceased by the beginning of
Paleocene time and was replaced by a period of uplift and
erosion, as evidenced by an unconformity of that age found
on all terranes of Kamchatka except the Omgon and
westernmost Sredinny Range terranes. In contrast, volcanic
arc facies of the Cape Kamchatka and Kronotsky terranes are
of Paleocene to Oligocene age and suggest convergent/
subduction activity commenced in the Early Tertiary. Plate
motion vector data suggest a scenario during this time that
differs from previous ideas. The Kula plate during this
time continued moving in a northwesterly direction of
convergence towards Kamchatka Peninsula. In contrast, the
Pacific plate at the beginning of this time interval
changed direction of motion from northwesterly to
north-northeast, and continued this direction of motion
until around 43 Ma. It is therefore possible that the Kula
plate did not extend as far west as Kamchatka in Early
Tertiary time and that the Pacific plate was located off
the coast of Kamchatka and did interact with the western
Aleutian Island arc, specifically, the Cape Kamchatka
terrane and the Komandorskie Islands. In this scenario,
transcurrent motion between the Pacific plate and the
Eastern Ranges occurred while underthrusting of the western
Aleutian arc occurred. This explains the lack of volcanic
material of any composition of this age throughout
Kamchatka except for the Cape Kamchatka terrane.

Alternatively, subduction of the Kula/Pacific ridge

166
crest in the Kuril Island arc system is suggested to have
occurred in Paleocene and Eocene time as evidenced by the
lack of magmatic activity of the arc and the period of
uplift and erosion (Kimura and Tamaki, in press). The
characteristics of no magmatism, uplift and erosion also
pertain to all of Kamchatka Peninsula except the Omgon,
Cape Kamchatka and westernmost Sredinny Range terranes. In
either case, it is difficult to reconcile these two events
occurring simultaneously, the Paleocene/Eocene unconformity
resulting from northwestward directed convergence of the
Kula plate and ridge subduction, and the development of the
western Aleutians, including Cape Kamchatka, in response to
northward directed convergence of the Pacific plate. Most
likely the presence of the ridge crest in the vicinity of a
subduction zone in conjunction with the small portion of
unsubducted plate remaining in Early Tertiary time led to a
complex oceanic plate/subduction zone interaction in which
forces other than those indicated by the plate motion
vector data were present. In addition, the presence of
other plates not accounted for in the plate motion vector
data in the vicinity of the northwest Pacific Basin at this
time would also complicate the situation.

By Late Eocene time, the second major plate
reorganization had occurred and the Kula plate had become
part of the Pacific plate due to the demise of the
Kula/Pacific spreading center. From 43Ma (Late Eocene) to

the present, the Pacific plate moved in a northwesterly

167
direction and converged towards
motion of the Pacific plate led
volcanics of the Sredinny Range

volcanic arcs. An accretionary

Kamchatka. The northwest
to the eruption of the

and the Greater Kuriles

event in Middle Miocene

time shifted the axis of the volcanism to the present day

Kuril-Kamchatka volcanic arc.

TECTONIC EVOLUTION OF KAMCHATKA PENINSULA

The tectonic evolution of Kamchatka Peninsula occurred
during Mesozoic and Cenozoic time, as inferred from the
ages of rocks of the peninsula, and was controlled by the
direction of motion of oceanic plates in the Pacific Basin
during the same time interval.

The oceanic plate configuration at the beginning of the
Late Jurassic period (165 Ma) consisted of two plates, the
Farallon plate, moving in a northeasterly direction and
occupying approximately the northern half of the Pacific
Basin, the vicinity of northeastern Siberia, and the
Izanagi plate, moving north and occupying the southwestern
portion of the Pacific Basin (fig. 29a). By 165 Ma,
direction of motion of the Farallon plate altered in such a
way as to initiate the subduction activity responsible for
the development of the Kvakhon/Omgon volcanic arc (fig.
29a), a correlation based on the similarities in timing of
the position of the Farallon plate and the paleontological
age dates obtained from volcanic arc facies of the Kvakhon
terrane. This age also correlates well with the abundant
Jurassic volcanic arc rocks found along the extent of the
Japanese Islands (Taira et al., 1983) indicating subduction
zone activity commenced in the Jurassic along a large
portion of the eastern Asiatic coast.

During the period of activity of the Kvakhon/Omgon arc,
from Late Jurassic to Early Cretaceous, the Farallon/

Izanagi ridge rotated in a clockwise direction and

168

 

 

 

 

-—.

169
swept along the eastern coast of Eurasia (figs. 29a, b, and
c). The Farallon plate continued convergence towards the
region of northeastern Siberia and the Izanagi plate
continued moving in a north to northeasterly direction
relative to Kamchatka. This scenario allows for the
possibility of a ridge-trench-transform triple junction
that existed during this time at the intersection of the
Farallon/Izanagi ridge with the Eurasian coast (figs. 29a
and b). Transcurrent motion between the Izanagi plate and
Eurasia occurred south of the triple junction and
convergent activity between the Farallon plate and Eurasia
occurred north of the triple junction. The location of the
triple junction migrated north along the Eurasian coast as
the Izanagi/Farallon ridge rotated clockwise in the Pacific
Basin.

The origin of the Malkinsk terrane and the reason for
its present location may be explained by the motion of the
oceanic plates and the presence of the triple junction.

The oldest ages of the granitic plutons of the terrane are
Jurassic and, taking into account their probable genetic
origin, indicates they originated during a Jurassic period
of subduction related plutonism, possibly in response to
underthrusting of the Farallon plate. The original
position of the terrane is unknown. The period of
transcurrent motion between Eurasia and the Izanagi plate
is proposed to have dislocated fragments of the Eurasian

margin onto the northward moving plate, including the

Malkinsk terrane, after passage of the triple junction to

 

170

 

 

Figure 29 - Late Jurassic to Late Cretaceous tectonic
evolution of Kamchatka Peninsula

a. Late Jurassic to Early Cretaceous
b. Hauterivian to Aptian

c. Albian

d. Cenomanian

171

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172
the north of the original location of the terrane (fig.
29b). Evidence favoring the idea is again found in Japan,
where Paleozoic and Mesozoic terranes have been emplaced as
a result of transcurrent plate motions and oblique
subduction (Taira et al., 1983). Some of the crustal
fragments in Japan are Devonian in age, corresponding to
the age of the spore assemblage found in the Malkinsk
terrane. In addition, Devonian aged rocks are also
reported from the Ust-Belaya ophiolite complex of the
Koryak Highlands and in northwestern Kamchatka (Fujita and
Newberry, 1983). The possibility therefore exists that
Devonian through Jurassic crustal fragments or blocks have
been rafted northward along the Mesozoic Asiatic margin in
a manner similar to what is observed in certain western
North American terranes, e.g., Wrangellia (Jones et al.,
1977), which led to the emplacement of Devonian blocks
along the Japanese and Siberian coast into Jurassic to
Early Cretaceous subduction zones.

Volcanic activity of the Kvakhon/Omgon arc is estimated
to have lasted until 115 Ma, Aptian (middle Cretaceous
time), the approximate time of change of direction of
motion of the Farallon plate from the northwest to
northeast. The lack of subduction related volcanic
activity on Kamchatka is indicated by Albian elastic
sediments found in several localities of the Omgon terrane
and by "middle Cretaceous" sediments found on the Kvakhon

terrane. Contemporaneously, the Malkinsk block was being

173
rafted northward on the Izanagi plate.

By 100 Ma, the Farallon plate had changed direction of
motion relative to northeast Siberia back to convergent,
i.e., to the northwest, and continued motion in such a
manner until around 90 Ma, the time of the first major
plate reorganization of the Pacific Basin oceanic plates.
In contrast, the Izanagi plate continued north to
northeasterly motion relative to Northeast Siberia from 115
Ma up to around 90 Ma. Based on the character of the
northward migrating triple junction and the lack of Albian
to Turonian volcanic rocks anywhere on chhatka, it may be
suggested that between 115 and 1OOMa, the junction had
passed the vicinity of Kamchatka Peninsula, an event that
would mark the end of Farallon/Kamchatka interaction and
the beginning of transcurrent Izanagi/Kamchatka interaction
(fig. 29c). A related event of importance is the
development of the Okhotsk-Chukotka volcanic arc in Aptian
time (around 116 Ma) and the duration of activity of the
arc, until Maastrichtian (around 70 Ma) time (Fujita and
Newberry, 1983). The arc rocks indicate a period of middle
to Late Cretaceous convergence, a time that coincides with
a period of only clastic sedimentation on the Kvakhon and
Omgon terranes of Kamchatka. Why arc volcanism did not
occur on these terranes at this time may be due to the
previously suggested period of transcurrent motion between
Kamchatka and the Izanagi plate. An interesting

alternative is that the Kvakhon/Omgon arc was not located

174
in its present position with respect to northeastern
Siberia, and may have been located to the south, away from
the convergent activity taking place to the north. Later
attachment of the arc to a northward moving plate brought
the arc to its present location.

One accretionary event of importance occurred during
this period of uncertain plate motions. The Malkinsk
terrane and the Kvakhon/Omgon arc, presumably juxtaposed
due to the northward motion of the Izanagi plate, accreted
in Albian or Cenomanian time (fig. 29d). The event thrust
the southern part of the arc over the Malkinsk terrane and
divided the are into the Kvakhon and Omgon terranes. The
"Diagonal geosuture", the boundary between the terranes,
may have originated at this time due to Obduction of only
the southern part of the arc. The timing of this event is
dated by radiometric age dates from metamorphic rocks of
the Kolpakova series of the Malkinsk terrane that average
97 Ma (early Cenomanian), the middle Cretaceous
unconformity of the Kvakhon terrane and the Cenomanian
unconformity of the Omgon terrane. In addition, the
deposition of the clastic Lesnovo series, a northeastern
extension of the Omgon series found in the Omgon terrane,
occurred at this time in response to the uplift and erosion
of the southwestern portion of the Omgon terrane. The
source terrane of both the Omgon and Lesnovo series is
suggested to have been the Kvakhon/Omgon arc and/or the
Malkinsk block.

 

175

Around 90 Ma, the reorganization that included the
cessation of spreading of the Izanagi/Farallon spreading
center and drastic changes in direction of motion of the
Kula plate, occurred. Northwesterly directed convergence
between northeast Siberia and the Kula plate commenced and
by 85 Ma, Santonian time, the volcanic arc activity of the
Iruney and Eastern Ranges arcs had commenced (fig. 30).
The arcs are may have formed along fracture zones located
on the Izanagi plate (fig. 29d) prior to the plate
reorganization episode.

Formation of the two arcs entrapped a fragment of
oceanic crust between them, presumably a portion of the
Izanagi plate, and marks the initial stage of development
of the Central Kamchatka Basin (fig. 30). The Late
Cretaceous arc system extended through the Sredinny Range
and Eastern Ranges terranes, through the Southern Kamchatka
terrane and into the Sea of Okhotsk, where Late Cretaceous
arc rocks are found on the Lesser Kuril Islands and on the
Academy of Sciences Rise.

The trench of each of the arcs is proposed to have been
located along their eastern margins based on the
predominance westward subducting active margins along the
western Pacific today. Specifically, the trench of the
Iruney arc may be identified as the narrow, elongate,
geophysically identified trough found along the western
edge of the Central Kamchatka Basin. No particular

geological or geophysical feature may be related to the

 

 

176

Figure 30 — Santonian to Maastrichtian tectonic evolution
of Kamchatka Peninsula

177

 

 

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178
trench associated with the Eastern Ranges arc but it was
probably to the east of the arc.

During the period of activity of the Iruney and Eastern
Ranges arcs, the parent material of the Ganal terrane, a
fragment of oceanic lithosphere, moved into the vicinity of
Kamchatka. A major Early Tertiary accretionary event (fig.
31) deformed and sheared the rocks into the
epidote-amphibolite metamorphic facies of the Ganal
series. The accretionary episode involved the amalgamation

of the Eastern Ranges arc and the Ganal terrane to western

 

Kamchatka, the thrusting of the allochthonous Iruney arc
facies over the eastern margin of the Malkinsk terrane, and
the compression and metamorphism of the Khavyven uplift, a
portion of the oceanic basement of the Central Kamchatka
Basin. The accretionary event may be attributed to the
collision of the Eastern Ranges arc to the Iruney arc, an
event that occurred when most or all of the oceanic crust
of the Central Kamchatka Basin had subducted under the
Iruney arc, thus closing the gap between the two arcs.
Continued northwesterly directed compressional stresses of
the Kula plate after the arcs juxtaposed were responsible
for the majority of the thrusting and metamorphic

activity. Deformation and metamorphism of the parent rocks
of the Ganal terrane occurred when a wedge of oceanic
lithosphere became entrapped between the accreting arcs and
was subjected to high pressure and temperature conditions.

The zone of shearing extended to the Avacha Inlet.

179

Figure 31 — Early Paleocene tectonic evolution of Kamchatka
Peninsula '

180

 

 

 

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181
Volcanic arc activity also ceased at the time of the
accretionary event, in Early Paleocene time, as evidenced
by the ensuing Paleocene to Oligocene period of uplift and
erosion devoid of the deposition of either Clastic or
volcanic facies.

Two possibilities exist for which plate interacted with
Kamchatka during the Early Tertiary. Either the Kula
plate, moving northwesterly with respect to northeast
Siberia or the Pacific plate, moving northerly with respect
to northeast Siberia, may have been located oceanward of
Kamchatka, although most likely a more complex plate system
occurred. The geology of Kamchatka in the Early Tertiary
consists of only minor clastic deposition and volcanic
activity and suggests either a Kula-Pacific ridge
subduction event, also suggested to have occurred in the
Kuril Islands during the same time interval (fig. 32a)
(Kimura and Tamaki, in press) or transcurrent motion
between Kamchatka and the Pacific plate (fig. 32b). The
presence of a northward migrating Kula/Pacific ridge in
this region of the Pacific Basin is uncertain as are the
oceanic plate boundaries at this time (Engebretson, 1982).
Two events that tend to support an interaction between a
northerly moving Pacific plate and Kamchatka are the
volcanic activity of the western Aleutian arc, including
the Komandorskie Islands and Cape Kamchatka, that commenced
in Paleocene or Eocene time and the emplacement of the

Olyutorsk terrane of the Koryak Highlands sometime

 

 

182

Figure 32a - Paleocene to Eocene tectonic evolution of
Kamchatka Peninsula with subduction of the
Kula/Pacific ridge

183

 

 

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Figure 32b — Paleocene to Eocene tectonic evolution of
Kamchatka with transcurrent motion between the
Pacific plate and Kamchatka

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186
in the same time interval (Fujita and Newberry, 1983).
Both these events, assuming the current spatial
relationships were also present in the Early Tertiary,
could be the result of northerly motion of the Pacific
plate.

In Eocene time, the second major plate reorganization
occurred that included the demise of the Kula/Pacific ridge
and the formation of a larger Pacific plate due to the
removal of the boundary separating the Kula and Pacific
plates. Following the reorganization, the Pacific plate
occupied the most of the Pacific Basin and moved in a
northwesterly direction of convergence with respect to
northeast Siberia. Portions of the Farallon plate
continued to exist but only along the western coasts of
North and South America.

The initiation of convergence between northeast Siberia
and the Pacific plate after the reorganization led to the
development of the Oligocene to Miocene Sredinny Range and
Greater Kuril volcanic arc (fig. 33). The trench
associated with the arc in the Kamchatka region was located
at the site of the present day Eastern Kamchatka Basin,
indicated by the presence of an accretionary wedge, and
continued south to connect with the Kuril trench off the
coast of the Southern Kamchatka terrane.

In the Greater Kuril Islands and the Southern Kamchatka
terrane, volcanism continued until Quaternary time without

change. However, in Kamchatka the axis of volcanic

187

Figure 33 - Oligocene to Miocene tectonic evolution of
Kamchatka Peninsula '

 

188

 

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ucuATKA 0L|GOCENE /

  

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Figure 33

189
activity changed in Pliocene time to the current observed
volcanic activity in the Eastern Ranges. The shift in the
axis of volcanism towards the Pacific Ocean was related to
the accretion of the Kronotsky terrane to Eastern Kamchatka
in Middle Miocene time (figs. 33 and 34). The Kronotsky
terrane, a Late Cretaceous or Paleocene to Oligocene
sequence of high alumina tholeiitic basalts, is inferred to
be separate from the Hawaiian/Emperor seamounts due to the
Maastrichtian age of the upper basalt layers of the Meiji
seamount, the northwesternmost end of the seamount chain,
found to the east of Kronotsky Peninsula. Although the
geochemical analysis of the basalts was obtained from only
five samples, it is interesting to note that the volcanic
rocks are of the same age as the volcanic rocks of the
western Aleutian arc.

The Kronotsky terrane approached the trench of the
Sredinny Range volcanic arc during Oligocene and Early
Miocene time with the Tyushevka Basin representing a narrow
sedimentary trough that formed between the accretionary
wedge and the approaching terrane. Deformation and thrust
faulting of the rocks of the Eastern Kamchatka Basin and
the Eastern Ranges occurred in Middle Miocene time when the
terrane accreted into the trench. The buoyancy and size of
the terrane, once introduced into the trench, led to a
shift in the locus of subduction from the Eastern Kamchatka
Basin and to the ensuing shift in the axis of volcanism to
the current observed position of the extensive Quaternary

volcanoes (fig. 34).

190

Figure 34 - Pliocene to recent tectonic evolution of
Kamchatka Peninsula

191

 

 

 
    

   
 
 

  

 

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Figure 34

CONCLUSIONS

Kamchatka Peninsula may be divided into ten
tectonostratigraphic terranes by utilization of the methods
of terrane analysis as outlined by Jones et al. (1983).
Each of the terranes formed as a result of plate tectonic
processes in oceanic tectonic environments. The primary
element of the terranes is oceanic crust, including
basalts, spilites and deepwater sediments sometimes
associated with ultramafic rocks, that is found at the base
of the stratigraphic sequence of seven of the ten terranes
(Kvakhon, Omgon, Sredinny Range, Central Kamchatka Basin,
Eastern Ranges, Southern Kamchatka and Cape Kamchatka).
The Kronotsky terrane is probably the result of volcanic
arc activity. The Ganal terrane is a fragment of oceanic
lithosphere, either a portion of oceanic crust or seamount
province, metamorphosed to a high degree. The Malkinsk
terrane, represented by abundant granitic plutons and
pelitic schists, is the result of subduction related
plutonism and metamorphism. Five different volcanic arcs
stitch together the terranes of Kamchatka. They are the
Late Jurassic to Early Cretaceous Kvakhon/Omgon arc, the
Late Cretaceous to earliest Tertiary Iruney and Eastern
Ranges arcs, the Oligocene to Miocene Sredinny Range arc
and the Quaternary Eastern Ranges/Southern Kamchatka arc.
In between the time periods of volcanic activity, erosion
and/or the deposition of clastic facies occurred. Ages of

the terranes, the dates of their formation and periods of

192

193
their development, occurred during Late Jurassic,
Cretaceous and Tertiary time with a distinct possibility
that some events may have occurred in Early and Middle
Jurassic time. The development of the Kvakhon/Omgon arc
and the Kolpakova series may have commenced in this time
interval. The tectonic evolution of Kamchatka occurred in
response to vectoral motions of oceanic plates in the
Pacific Basin during Mesozoic and Cenozoic time. The
oceanic plates include the Farallon, Izanagi, Kula and
Pacific plates. Although the boundaries of these plates
and Eurasia are not known with great accuracy as are the
positions of the terranes of Kamchatka through Mesozoic and
Cenozoic time, a correlation can be made between the
oceanic plate motions and events of the terranes of
Kamchatka. Finally, tectonic events of Kamchatka may be
related to tectonic events of adjacent areas, besides the
oceanic crustal plates, and include the Kuril and Aleutian

Island arcs and the Sea of Okhotsk.

LIST OF REFERENCES

LIST OF REFERENCES

Aksenovich, A. V., V. N. Bondarenko, G. M. Vlasov, I. F.
Moroz and L. I. Tikhomirov, 1964, Mesozoic
stratigraphy, in G. M. Vlasov, ed., Geology of the
USSR, v. 31, Kamchatka and the Kurile and
Komandorskie Islands: Moscow, Nedra Publishing
House, p. 79-103 (in Russian).

Aprelkov, S. E., and Y. V. Zhegalov, 1972, Volcanic belts
of Kamchatka: Geotectonics, v. 6, p. 123—126.

Aprelkov, S. Y., 1971, The tectonics and history of
volcanism in southern Kamchatka: Geotectonics, v.

5, p. 88-94.

Aubouin, J., 1965, Geosynclines (Developments in
geotectonics I), Amsterdam - London - New York,
Elsevier Pub. Co., 355 pp.

Avdeiko, G. P., 1971, Evolution of geosynclines on
Kamchatka: Pacific Geology, v. 3, p. 1—13.

Belyy, V. F., 1974, Comparative tectonics of volcanic arcs
in the western Pacific: Geotectonics, v. 8, p.
241-250.

Burk, C. A., and G. S. Gnibidenko, 1977, The structure and
age of acoustic basement in the Okhotsk Sea, in M.
Talwani and W. C. Pitman, III, eds., Island arcs,
deep sea trenches and back-arc basins: Washington,
DC, American Geophysical Union, M. Ewing Series 1,

p. 451-461.

Chukhonin, A. P., 1978, A mass—spectrometric study of the
forms taken by lead in zircon: Geochemistry
International, v. 15, p. 186—189.

Coney, P. J., D. L. Jones and J. W. H. Monger, 1980,
Cordilleran suspect terranes: Nature, v. 288, p.

329-333.

Cormier, V. F., 1975, Tectonics near the junction of the
Aleutian and Kuril-Kamchatka arcs and a mechanism
for middle Tertiary magmatism in the Kamchatka
Basin: Geological Society of America Bulletin, v.

86, P- 443-453-

Csetjey, B., Jr., D. P. Cox, R. C. Evarts, G. D. Stricker
and H. L. Foster, 1982, The Cenozoic Denali fault
system and the Cretaceous accretionary development
of southern Alaska: Jour. of Geophysical Research,

v. 87, B5, p. 3741-3754.
194

 

195

Delong, S. E., P. J. Fox and F. W. McDowell, 1978,
Subduction of the Kula ridge at the Aleutian
trench: Geological Society of America Bulletin, v.

89: p- 83-95-

Dmitriyeva, V. K., 1981, The tectonic nature of the
so-called marginal West Kamchatka trough:
International Geology Review, v. 23, p. 1266-1274.

Dobretsov, N. L., 1975, Metamorphic belts of the
northwestern Circum-Pacific region: Geological
Society of America, Special Paper 151, pp. 133-144.

Dobretsov, N. L., and I. Kuroda, 1970 Geologic laws
characterizing glaucophane metamorphism in
northwestern part of the folded frame of Pacific
Ocean: International Geology Review, v. 12, p.

1389-1407.

Engebretson, D. C., 1982, Relative motions between oceanic
and continental plates in the Pacific basin: PhD
Dissertation, Stanford University, 211 p.

Engebretson, D. C., A. Cox and G. A. Thompson, 1984,
Correlation of plate motions with continental
tectonics: Laramide to Basin-Range: Tectonics, v.

3, p. 115-119.

Erlich, E. N., 1979, Recent structures of Kamchatka and
position of Quaternary volcanoes: Bulletin
Volcanologique, v. 42, p. 13—43.

Florenskiy, I. V., and P. V. Florenskiy, 1972, Role of
paleovolcanic rocks in the structure of eastern
Kamchatka: Academy of Sciences of the USSR,
Doklady, Earth Science Sections, v. 205, p. 84-87.

Fujita, K., and J. T. Newberry, 1983, Accretionary terranes
and tectonic evolution of northeast Siberia, in M.
Hasimoto and S. Uyeda, eds., Accretion tectonics in
the circum-Pacific regions: Tokyo, Terra Scientific
Publishing Company p. 43-57.

Herman, L. L., S. A. Scheka and V. I. Shul'diner, 1978,
Metamorphic complexes of the Ganalsky Range,
Kamchatka: Pacific Geology, v. 13, p. 49-64.

Gnibidenko, H. S., T. G. Bykova, O. V. Veselov, V. M.
Vorobiev and A. S. Svarichevsky, 1983, The tectonics
of the Kuril-Kamchatka deep-sea trench in T.W.C.
Hilde and S. Uyeda, eds., Geodynamics of the Western
Pacific-Indonesian region: Washington, DC, American
Geophysical Union Geodynamics Series, v. 11, pp.

249-285.

196

Gnibidenko, H. S., S.Z. Gorbachev, M. M. Lebedev and V. I.
Marakhanov, 1974, Geology and deep structure of
Kamchatka Peninsula: Pacific Geology, v. 7, p.
1-32.

Gnibidenko, H. S., and I. I. Khvedchuk, 1982, The tectonics
of the Okhotsk Sea: Marine Geology, v. 50, p.
155-198-

Gnibidenko, H. S., and V. I. Marakhanov, 1973, Structure of
the east Kamchatka anticlinorium: Academy of
Sciences of the USSR, Doklady, Earth Science
Sections, v. 210, p. 74-77.

Gnibidenko, H. S. and L. V. Svarichevskaya, 1984, The
submarine canyons of Kamchatka: Marine Geology, v.
54, P. 277-308.

Heirtzler, J. R., G. O. Dickson, E. M. Herron, W. C.
Pitman, III, and X. Le Pichon, 1968, Marine magnetic
anomalies, geomagnetic field reversals and motions

of the ocean floor and continents: Journal of
Geophysical Research, v. 73, No. 6, p. 2119-2136.

Henderson, L. J., R. G. Gordon and D. C. Engebretson, 1984,
Mesozoic aseismic ridges on the Farallon plate and
southward migration of shallow subduction during the
Laramide orogeny: Tectonics, v. 3, p. 121-132.

Hilde, T. W. C., S. Uyeda and L. Kroenke, 1977, Evolution
of the western Pacific and its margin:
Tectonophysics, v. 38, p. 145-165.

Hyndman, D. W., 1972, Petrology of igneous and metamorphic
rocks: New York, McGraw-Hill, Inc., 533 p.

Isacks, B., J. Oliver and L. R. Sykes, 1968, Seismology and
the new global tectonics: Journal of Geophysical
Research, v. 73, No. 18, p. 5855-5899.

Jones, D. L., N. J. Silberling and J. W. Hillhouse, 1977,
Wrangellia - a displaced terrane in northwestern
North America: Canadian Journal of Earth Sciences,

v. 14, p. 2565-2577.

Jones, D. L., N. J. Siberling, W. Gilbert and P. Coney,
1982, Character, distribution and tectonic
significance of accretionary terranes in the central
Alaska range: Journal of Geophysical Research, v.
87, B5, p. 3709-3717.

197

Jones, D. L., D. G. Howell, P. J. Coney and J. W. H.
Monger, 1983, Recognition, character, and analysis
of tectonostratigraphic terranes in western North
America, in M. Hashimoto and S. Uyeda, eds.,
Accretion tectonics in the circum-Pacific regions:
Tokyo, Terra Scientific Publishing Company, p.

21-35.

Kay, G. M., 1951, North American geosynclines: Geological
Society of America Memoir no. 48, 143 pp.

Khotin, M. Y., 1972, Siliceous rocks in the Late Cretaceous
volcanic-tuffaceous-siliceous sequence at
Kamchatskii Cape: Lithology and Mineral Resources,

v. 7, p. 338-349.

Kimura, G. and Tamaki, K., Tectonic framework of the Kuril
arc since its initiation, in press.

Krasny, L. I., 1964, Geologic map of the northwestern part
of the Pacific mobile belt: Ministry of Geology of
the USSR, scale 1:1,SO0,000.

Kuz'min, V. K., and A. P. Chukhonin, 1980, Precambrian age
of gneisses of the Kamchatka pluton: Academy of
Sciences of the USSR, Doklady, Earth Science
Sections, v. 251, p. 61-63.

Lebedev, M. M., I. A. Tararin and E. A. Lagovskaya, 1967,
Metamorphic zones of Kamchatka as an example of the
metamorphic assemblages of the inner part of the
Pacific belt: Tectonophysics, v. 4, p. 445-461.

Legler, V. A. and I. V. Florenskiy, 1976, Structural
position of thrust faults of the Valaginsky Range,
Kamchatka: Academy of Sciences of the USSR,
Doklady, Earth Sciences Section, v. 226, p. 33—35.

Le Pichon, X., 1968, Sea-floor spreading and continental
drift: Journal of Geophysical Research, v. 73, No.
12, p. 3661-3705.

Levin, L. E., A. P. Milashin and Yu. G. Zorina, 1970, The
basins of the far eastern seas, in V. V. Fedynskiy
and L. E. Levin, eds., The tectonics and oil and gas
potential of the marginal and inland seas of the
USSR: NILZarubezhgeologiya, Issue No. 20,
Leningrad, "Nedra" Press, pp. 95-127.

Markov, M. S., V. A. Seliverstov, M. Y. Khotin and B. K.
Dolmatov, 1969, Junction of east Kamchatka
structures and the Aleutian island arc:
Geotectonics, v. 3, p. 314-319.

198

Markov, M. S., G. Y. Nekrasov and M. Y. Khotin, 1972,
Basement of the Cretaceous geosyncline on the
Kamchatka Cape Peninsula (eastern Kamchatka):
Geotectonics, v. 6, p. 246—249.

Markov, M. S. and M. Y. Khotin, 1973, Structures and
geologic history of the Kuril-Kamchatka island arc,
in P. J. Coleman, ed., The Western Pacific, Univ. of
Western Australia Press, Nedlands, p. 239—246.

Markovskiy, B. A. and V. K. Rotman, 1971, Geosynclinal
meymechite of Kamchatka: Academy of Sciences of the
USSR, Doklady, Earth Sciences Section, v. 196, p.
158-161.

McWilliams, M. O. and D. G. Howell, 1982, Exotic terranes
of western California: Nature, v. 297 p. 215-217.

Mironoba, L. V., 1982, Stratigraphic dictionary of the
USSR: Paleogene—Neogene—Quaternary systems:
Leningrad, Nedra, 616 p.

Mokrousov, V. P., and A. F. Marchenko, 1964, Precambrian
and Paleozoic stratigraphy, in G. M. Vlasov, ed.,
Geology of the USSR, v. 31, Kamchatka and the Kurile
and Komandorski Island: Moscow, Nedra Publishing
House, p. 55-79 (in Russian).

Morgan, W. J., 1968, Rises, trenches, great faults, and
crustal blocks: Journal of Geophysical Research, v.
73, No. 6, p. 1959-1982.

Nalivkin, D. V., 1973, Geology of the USSR: Univ. of
Toronto Press, Toronto, 855 p.

Newberry, J. T., 1983, Seismicity and tectonics of the far
western Aleutian Islands: M. S. Thesis, Michigan
State University, 93 p.

Page, B. M. and D. C. Engebretson, 1984, Correlation
between the geologic record and computed plate
motions for central California: Tectonics, V. 3, p.

133- 155.

Potap'ev, S. V. and V. I. Marakhanov, 1974, Subsurface
structure of eastern Kamchatka and the structure of
the Kumroch Range: Academy of Sciences of the USSR,
Doklady, Earth Sciences Section, v. 215, p. 205—207.

Pushcharovskiy, Ju. M., V. P. Zinkevich, A. O. Mazarovich,
A. A. Peyve, Yu. N. Raznitsin, A. V. Rikhter and N.
V. Tsukanov, 1983, Overthrusts and imbricate
structures of the northwestern Pacific margin:
Geotectonics, v. 17, p. 466-477.

199

Rivosh, L. A., 1964, Some geophysical data bearing on deep
structure of the Central Kamchatka trough:
International Geology Review, v. 6, p. 2009-2014.

Rotman, V. K., 1960, Neogene lahar deposits of Kamchatka:
Academy of Sciences of the USSR, Doklady, Earth
Sciences Section, v. 134, p. 914-916.

Rotman, V. K., 1964, Diagonal suture of western Kamchatka:
Academy of Sciences of the USSR, Doklady, Earth
Science Sections, v. 159, p. 61—63.

Rotman, V. K., and B. A. Markovskiy, 1968, Types of
geosynclinal basalt magmas in Kamchatka: Academy of
Sciences of the USSR, Doklady, Earth Science
Sections, v. 182, p. 70-72.

Rotman, V. K., B. A. Markovskiy and M. I. Khotina, 1973,
The Kamchatka ultrabasic province: International
Geology Review, v. 15, p. 1015-1024.

Rozen, O. M., and M. S. Markov, 1973 Origin of amphibolites
and the metamorphic melanocratic basement of island

arc (Ganal Range, Kamchatka): Geotectonics, v. 7,
p. 136-142.

Sadreev, A. M., and B. K. Dolmatov, 1965, New data on the
thickness and age of effusive-pyroclastic and
tuffogenic-sedimentary formations of Kronotski
Peninsula: Academy of Sciences of the USSR,
Izvesti a, Geology Series, n. 7, p. 122-126 (in
Russian).

Savostin, L., L. Zonenshain and B. Baranov, 1983, Geology
and plate tectonics of the Sea of Okhotsk, in T. W.
C. Hilde and S. Uyeda, eds., Geodynamics of the
western Pacific-Indonesian region: Washington, DC,
American Geophysical Union, Geodynamics Series, v.
11, p. 189-221.

Schermer, E. R., D. G. Howell and D. L. Jones, 1984, The
origin of allochthonous terranes: perspectives on
the growth and shaping of continents: Annual Review
of Earth and Planetary Sciences Letters, v. 12, p.
107-131.

Seliverstov, V. A. and A. G. Tsikunov, 1974, Meymechite in
the northern part of the Valaginsky Range, eastern
Kamchatka: Academy of Sciences of the USSR,
Doklady, Earth Sciences Section, v. 217, p. 60—62.

2OO

Serova, M. Y., V. M.Gundobin, V. K. Dimitriyeva and T. V.
Sverbilova, 1970, Rzehakina epigona zone in volcanic
terrigenous formations of the Eastern Range,
Kamchatka: Academy of Science of the USSR, Doklady,
Earth Science Sections, v. 190, p. 72-73.

Shantser, A. Y., A. I. Chelebayeva and A. R. Geptner, 1965,
More facts about the stratigraphy of sedimentary and
volcanic rocks of the Neogene of Kamchatka: Academy
of Sciences of the USSR, Doklady, Earth Sciences
Section, v. 162, pp. 116-118.

Shapiro, M. N. 1980, The Grechiskin overthrust on the
shores of Kamchatka Gulf: Geotectonics, v. 14, p.

234-240.

Shapiro, M. N., 1981, Relationship between geosynclinal and
island-arc regimes (as exemplified by Kamchatka):
Geotectonics, v. 15, p. 363-374.

Shapiro, M. N., and V. A. Seliverstov, 1975, Morphology and
age of folded structures in eastern Kamchatka, at
the latitude of the Kronotskiy Peninsula:
Geotectonics, v. 9, p. 240-244.

Shmidt, O. A., 1978,Tectonics of the Komandorskie Islands
and structure of the Aleutian Ridge: Mowcow, Nauka
Publishing House, 100 p. (in Russian).

Shtempel, B. M., 1957, Age of the conglomerates of the
metamorphic series of the central Kamchatka Range:
Academy of Sciences of the USSR, Doklady, Earth
Sciences Section, v. 114, p. 465-466.

Shul'diner, V. I., S. V. Vysotskiy and A. I. Kanchuk, 1979,
The crystalline basement of Kamchatka: structure
and evolution: Geotectonics, v. 13, p. 136-145.

, 1980, Two types of pre-Mesozoic metamorphism in
the Central Range, Kamchatka: Academy of Sciences
of the USSR, Doklady, v. 251, p. 96-99.

 

Sidorchuk, I. A., and A. I. Khanchuk, 1981, Mesozoic
glaucophane schist complex from western slope of
Central Range of Kamchatka: Geologi a i Geofizika,
v. 255, n. 3, p. 150-156 (in RussianI.

Sivertseva, I. A., and A. N. Smirnova, 1974, On the
discovery of Paleozoic spores in metamorphosed
deposits on Kamchatka: Soviet Geology and
Geophysics, v. 15, n. 6, p. 106-107.

201

Smirnov, A. M. and S. M. Sinitsa, 1975, Structural
relationships between Upper Cretaceious and
underlying rocks in the Central Range, Kamchatka:
Academy of Sciences of the USSR, Earth sciences
Section, v. 222, p. 107-109.

Smirnov, L. M., 1971, The tectonics of west Kamchatka:
Geotectonics, v. 5, p. 186-192.

Suprunenko, O. I., 1972, Relationship between the
structures of eastern Kamchatka and the Pacific
Ocean floor: Academy of Sciences of the USSR, Earth
Sciences Section, v. 206, p. 46-48.

Suprunenko, O. I., 1976, Time of formation and development
of the Kurile-Kamchatka deep-sea trench: Academy of
Sciences of the USSR, Doklady, Earth Science
sections, v. 227, p. 112-113.

Suprunenko, O. I., 1977, Possible association between
intensity of modern volcanism and horizontal
movements of the crust in eastern Kamchatka:
International Geology Review, v. 19, p. 947-950.

Suprunenko, O. I. and B. A. Markovskiy, 1973, Alkalic
volcanic rocks of the Kronoki Peninsula, Kamchatka:
Academy of Sciences of the USSR, Doklady, Earth
Sciences Section, v. 211, p. 172-175.

Taira, A., Y. Saito and M. Hasimoto, 1983, The role of the
oblique subduction and strike-slip tectonics in the
evolution of Japan, in T. W. C. Hilde and S. Uyeda,
eds., Geodynamics of the western Pacific—Indonesian
region: Washington, DC, American Geophysical Union,
Geodynamics Series, v. 11, p. 303—316.

Tararin, I. A., 1977, Origin of granulites of the
Ganal'skiy Range, Kamchatka: Academy of Sciences of
the USSR, Doklady, Earth Sciences Section, v. 234,
p. 200-203.

Tikhonov, V. 0., 1968, Overthrusts in eastern Kamchatka:
Geotectonics, v. 2, p. 185-190.

Tschudy, R. H., 1969, Relationship of palynomorphs to
sedimentation, in R. H. Tschudy and R. A. Scott,
eds., Aspects of palynology: New York,
Wiley-Interscience, p. 79-96.

Tsikunov, A. G. and V. S. Petrov, 1973, Overthrust in
Vostochnyy Khrebet (Eastern Range) Kamchatka:
International Geology Review, v. 15, p. 208-212.

202

Utnasin, V. K., A. I. Abdurakhimov, G. I. Anosov, S. T.
Balesta, Y. A. Budyanskiy, Y. K. Markhinin and V. I.
Fedorenko, 1975, Deep structure of Klyuchevskoy
group of volcanoes and problem of magmatic hearths:
International Geology Review, v. 17, p. 791-806.

Volynets, O. N., A. V. Koloskov, G. B. Flerov, D. I.
Frikh-Khar and N. L. Shilin, 1965, Differentiation
of the Tertiary plutonic volcanic rocks of central
Kamchatka into associations: Academy of Sciences of
the USSR, Earth Sciences Sections, v. 165, pp. 9-12.

Voronkov, Y. S., and V. N. Smirnov, 1971, New data on the
age of Cretaceous sediments of the Moroschechnyy
Range, southwestern Kamchatka: Academy of Sciences
of the USSR, Earth science Sections, v. 200, p.
52-53.

Vysotskiy, S. V., and A. A. Gracheva, 1981, Precambrian age
of the Olenegorskiy basement swell in the
eugeosynclinal zone of eastern peninsulas of
Kamchatka: Academy of Sciences of the USSR,
Doklady, Earth science Sections, v. 257, p. 101-103.

Wallace, W. K. and D. C. Engebretson, 1984, Relationships
between plate motions and Late Cretaceous to
Paleogene magmatism in southwestern Alaska:
Tectonics, v. 3, p. 295—315.

Zhegalova, G. V., 1981, Melange in the massifs of the
gabbro-norite-cortlandite complex of the Sredinnyy
(Middle) Range of central Kamchatka: Geotectonics,

V. 15’ p- 273-278.

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