气候变化领域集成服务门户

The early archaeological record of Beringia is complicated by the occurrence of several lithic industries. Site assemblages, dating from 14,000 to 12,800 years ago and located from the Yana-Indigirka Lowlands of Siberia to the upper Tanana River basin, contain artifacts characteristic of the Nenana technological complex. After 12,800 years ago, site assemblages contain artifacts diagnostic of the Denali technocomplex. To explain the variation in lithic industries, we first and foremost need well-stratified and well-dated sites with multiple components so we securely know their ages and depositional relationships. We present excavation results of one such site located in interior Alaska, Owl Ridge, with the goal of assessing site stratigraphy, radiocarbon chronology, and natural site formation processes. Owl Ridge was visited three times during the Pleistocene-Holocene transition with a Nenana-complex occupation at 13,380-12,800 years ago followed by two Denali-complex occupations at 12,540-11,430 years ago and 11,270-11,200 years ago. Assemblage change at Owl Ridge was diachronically patterned, as at the nearby Dry Creek archaeological site, and separated by two climatic events, a brief extremely windy Younger Dryas (lasting 300-250 years) and a very brief wetter period (lasting similar to 160 years). Our results indicate these climate and environmental conditions played a role in settlement of eastern Beringia.