Archaeological Geology of the Archaic Period in North America
Landscape development and the location of evidence of Archaic cultures in the Upper Midwest
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Published:January 01, 1995
Regional patterns of Holocene landscape evolution are superimposed on Archaic Period cultural patterns of settlement and material discard resulting in the archaeological record preserved today. In the Upper Midwest, Archaic remains are abundant on upland hillslopes and exhibit spatial and temporal patterning at scales of both individual hillslope components and interfluves in response to development of Holocene erosion surfaces. Broad upland divides exhibit a paucity of Archaic deposits; whether this is due to a lack of occupation or to shallow burial by eolian, sheetflood, or pedogenic processes has yet to be demonstrated. Intact Archaic deposits are rarely found on modern ground surfaces of colluvial slopes, alluvial fans, and flood plains, but are frequently found buried and well preserved within deposits comprising these landforms. Net aggradation of these landform-sediment assemblages occurred during the early and middle Holocene in response to climatic and vegetation change, and as internal response of the fluvial system to changes in water and sediment supply. Pulses of sediment delivered to the drainage network were genetically related to Holocene erosion surfaces developing on the valley slopes. Archaic deposits are buried in major river valleys of the region, except where they occur on late Wisconsinan terraces. Because of the myriad of interacting factors and often unique late Pleistocene history of large valleys, many of their landforms tend to be idiosyncratic details of morphology and evolution, both spatially and temporally.
Patterns of post-Archaic landscape changes also affected the record of the Archaic in systematic ways. Hillslopes were subject to only limited sheetflood erosion and sedimentation, whereas low- to medium-order drainages and their alluvial fans were incised in response to increased runoff and gully erosion. As a result, early and middle Holocene Archaic-bearing valley sediments were partially removed and the remaining flood plains and fan surfaces became relict landscape elements.
- alluvial fans
- archaeology
- Cenozoic
- clastic sediments
- colluvium
- erosion
- Great Plains
- Illinois
- Iowa
- land use
- landform evolution
- landforms
- landscapes
- Midwest
- Mississippi Valley
- Missouri
- North America
- Northern Great Plains
- paleoenvironment
- patterns
- pedogenesis
- Pleistocene
- Quaternary
- sediment supply
- sediments
- soils
- stratigraphy
- terraces
- United States
- upper Pleistocene
- upper Wisconsinan
- vegetation
- Wisconsinan
- Illinois Valley
- DeForest Formation
- Archaic
- Des Moines River valley