Big Eddy Site, Missouri
- PDF / 1,945,312 Bytes
- 30 Pages / 595.276 x 790.866 pts Page_size
- 90 Downloads / 210 Views
BERINGIA, GEOARCHAEOLOGY Joshua D. Reuther1,2 and Ben A. Potter2 1 University of Alaska Museum of the North, Fairbanks, AK, USA 2 Department of Anthropology, University of Alaska Fairbanks, Fairbanks, AK, USA
The Bering Land Bridge and Beringia: definitions and geography The relatively shallow Bering Sea continental shelf lies between the Arctic and Pacific Oceans separating the coasts of Alaska and Siberia (Figure 1); it was exposed during periods of extensive continental glaciation, as moisture was locked up in the glaciers and sea level dropped about 100 m below modern levels. The exposure of this shelf established what is referred to as the Bering Land Bridge, a nearly 1,000 km wide land-based connection between northeastern Asia and northwestern North America. This area, when exposed, forms the once 34 million acre continental mass known as Beringia (Hopkins, 1959; Hultén, 1968; Barber, 2005). During the major episodes of glaciation of the Pleistocene, the extensive northern North American Laurentide and Cordilleran ice sheets coalesced in the region of Alberta, Canada, creating barriers for biotic migration to the east and south. During this period, Alaska and portions of far northwestern Canada were effectively part of northeastern Asia, permitting the exchange of animals, flora, and humans between the two continents and forming the unique blend of Asiatic and North American biotic and cultural systems (Hultén, 1968; Hopkins et al., 1982; Guthrie, 1990; Hoffecker and Elias, 2007). Hultén (1968) first coined the term “Beringia” to refer to the Bering Land Bridge itself; however, its use has taken on a variety of geographic meanings. Others have
broadened the geographic boundaries for the term to include extensive portions of unglaciated Northeast Asia, Alaska, and the Yukon and Northwest Territories of Canada (see Hopkins et al., 1982; Hoffecker and Elias, 2007; and Dixon, 2013 for excellent discussions on the history of the concepts of the Bering Land Bridge and Beringia). Typically, Beringia has been subdivided into three regions: central, eastern, and western. The unglaciated areas of Northeast Asia, generally from the eastern Siberian Verkhoyansk Range to the western shores of the Bering Strait, comprise western Beringia, while those of Alaska, Yukon, and the Northwest Territories compose eastern Beringia. The area of the Bering Land Bridge itself is usually referred to as central Beringia (West, 1981; Hoffecker and Elias, 2007), consisting of the submerged lowlands of the Bering Sea continental shelf and the former highlands that are now the islands of the Bering and Chukchi Seas. Others have recently extended the definition of Beringia to include portions of southeastern Alaska and the northwestern coast of British Columbia that were once exposed unglaciated lands along coastlines during the Last Glacial Maximum (LGM: 23,000–19,000 cal BP; Dixon, 2013). The exposure of the Bering Land Bridge forced the oceanic moisture sources of the Pacific and Arctic Oceans farther away from interior regions of Ber
Data Loading...
