Late Glacial and early Holocene geoarchaeology and terrestrial paleoecology in the lowlands of the middle Tanana Valley, subarctic Alaska.

摘要

This dissertation project focuses on three study areas in the middle Tanana Valley (mTV) to provide records of local terrestrial ecological contexts and environmental changes in lowland settings that dated to the Late Glacial and early Holocene (16,000 to 6,000 cal. years ago) in interior Alaska and Eastern Beringia. The archaeological record of the mTV provides a rich history of hunter-gatherer land use dating over 14,000 years old. This project is part of two larger projects focused on prehistoric human ecology and foraging behavior in Eastern Beringia: the Quartz Lake-Shaw Creek Flats Multidisciplinary and Upward Sun River Site Projects.;The study areas are spread out across a 4,000 km2 area in the mTV and contain the presence of archaeological sites that have records of well-developed stratification of sediments and soils and preserved macrofossils. Two of the study areas are dune fields: the Little Delta Dunes (including the Upward Sun River Site) and Rosa-Keystone Dunes Fields; the third area is Quartz Lake, one of the largest lakes within the region. As a whole they provide important information to understand the evolution of regional landscapes, paleoecological systems, and paleoenvironmental conditions dating back to 25,000 years ago, over 10,000 years prior to the currently accepted earliest human occupation of the region.;Late Glacial and early Holocene landscapes of the mTV were ones of moderate stability and landscape disturbance with high rates of loess and aeolian sand deposition, and the presence of early-to-middle successional vegetation communities (herbs and forbs, shrubs, and deciduous trees) that fostered the presence of diverse mammalian faunal communities that no longer coexist in the region. As the middle Holocene approached, landscapes became increasingly stable with the expansion of the boreal forest and aeolian deposition drastically decreased throughout the mTV. The disturbances that fostered the highly productive early-to-middle successional vegetative communities in the Late Glacial and early Holocene became progressively partitioned in the middle Holocene and primarily relegated to active floodplains. These local ecological contexts can be used to assess changes in Late Glacial and Holocene faunal diversity and in human ecology and foraging behavior in interior Alaska and Eastern Beringia.