The purpose of this dissertation is to (1) map relict deltas that formed between ≈21.0 and 13.0 cal ka BP in the Lower Peninsula of Michigan, and (2) group those that have similar geomorphic, sedimentologic, and environmental components. In the past, beach ridges, wave-cut bluffs, meltwater spillways, and spits have been the primary relict landforms used to document and analyze paleolakes and coastal conditions in Michigan. This study highlights how, in addition to simply providing evidence for a paleolake, relict deltas may also be important proxies for coastal and terrestrial conditions during deglaciation.Elevation data, stratigraphic information from well (water, oil, and gas) logs, along with surface and subsurface textural data derived from soil maps, enabled me to map 61 Pleistocene deltas in Lower Michigan. Of these, 27 had been known from previous works, whereas 34 are unique to this study. Most of the deltas are graded towards a known, ancestral, paleo-lake; however 16 deltas, many of which are kamic deltas, terminate into an unidentified and currently unknown or unstudied paleolake and/or lake stage.Results from a numerical grouping analysis of the deltas confirm that relict late-Pleistocene deltas – at least those in Lower Michigan - have topographic and sedimentologic characteristics that facilitate placing them into unique morphologic groups. The grouping analysis suggests that there are at least five different, distinct types of relict deltas in Lower Michigan. The majority of Group 1 deltas are relatively large, sandy, and arcuate-shaped, with sandy textured catchments. Group 2 deltas are also mostly sandy and arcuate-shaped but are relatively small; many of these deltas were sourced from a (likely) stagnant ice margin. Both Group 1 and 2 deltas are mostly located in northern Michigan. The bulk of Group 3 deltas are also sandy and arcuate-shaped, but unlike deltas in Groups 1 and 2, they have fine textured catchments and are more widely distributed. Most Group 4 deltas are relatively large, fine textured, arcuate-shaped, and have fine textured catchments; all Group 4 deltas are located in SE Michigan. The soils on these deltas are mostly fine-textured suggesting that these deltas were perhaps submerged by higher succeeding lake levels. Group 5 deltas are elongate-shaped, with multiple midchannel bars and interpreted as fluvial-dominated deltas. These deltas, all located in central Michigan, have formed at the mouths of major meltwater spillways. Arcuate-shaped deltas (Groups 1-4) are the most common type of relict delta in Lower Michigan; these deltas are interpreted as wave-dominated deltas. They are common on the eastern margins of the Lower Peninsula, in association with large lakes, where they confirm the strong, persistent and sustained winds and wave energies in the Great Lake region at this time. Several methods have been used to record paleo-water plane elevations from relict beach ridges, wave-cut bluffs, meltwater spillways, and spits. Future studies of these relict coastal features in conjunction with relict deltas will provide a proxy for both paleocoastal and paleoterrestrial conditions.By identifying and studying 61 relict deltas in Lower Michigan, I hope to promote further research on such systems within the Great Lakes region. Detailed and comprehensive investigations on Pleistocene deltas will advance our understanding of lake-level and landscape dynamics, along with wave and wind energies and directionalities during the late Pleistocene.
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