GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 227-3
Presentation Time: 2:15 PM

PLEISTOCENE-HOLOCENE EVOLUTION OF LANDSCAPES AND SUBSISTENCE OPPORTUNITIES AT BERING PIEDMONT GLACIER, NORTHERN GULF OF ALASKA


CROSSEN, Kristine J., Geological Sciences, University of Alaska, 3211 Providence Dr, Anchorage, AK 99508; Geological Sciences, University of Alaska, 21741 Woodcliff Dr, Chugiak, AK 99567-5381, YESNER, David R, Anthropology, University of Alaska, 3211 Providence Dr, Anchorage, AK 99508; Geological Sciences, University of Alaska, 3211 Providence Dr, Anchorage, AK 99508 and PASCH, Anne D, Geological Sciences, University of Alaska, 3211 Providence Dr, Anchorage, AK 99508; Geological Sciences, University of Alaska, 3211 Providence Dr, Anchorage, AK 99508, kjcrossen@alaska.edu

The Bering Glacier region experienced dramatic changes from 15,000 BP to the present. Following catastrophic glacier retreat, an embayed marine landscape was exposed and offered habitat for edible invertebrates and pinnipeds. The subseqent Little Ice Age (LIA) glacial advance buried this landscape with a broad outwash plain covered with forests surrounding a deep lake basin (Vitus Lake).

Late Pleistocene retreat of Bering Glacier resulted in a recession off the coastal plain and up Bering Fiord, leaving a landscape of elongated peninsulas and islands surrounded by various shorelines inhabited by edible invertebrates and populations of cryophilic pinnnipeds between 15.000 and 5,000 BP. Early Alaskan human inhabitants would have found bountiful shorelines and protected waterways. By 4,000 BP this marine environment changed to a terrestrial environment of forests, peat bogs and lakes likely due to regional uplift.

The LIA advance sometime after 1000 AD appears to be the most substantial Holocene advance of Bering Glacier and brought the ice margin to the Pacific shoreline by the late 1800s AD. Immense outwash plains filled the former fiords with gravel and buried the islands leaving a broad continuous shoreline.

Today post-LIA retreat reveals the deep narrow fiords and multiple basins now filled by the freshwater Vitus Lake. This lake currently occupies the older marine embayment and is sealed from the ocean by large continuous outwash plains topped by beach ridges. This produces a dangerous open coastline which presents far fewer possibilities for maritime subsistence and settlement.