Late Cenozoic geology, Ancient Pacific Margin NATMAP Project, report 5: paleoecology and proxy climatic change records, south Klondike placer region, Yukon Territory

Abstract

Aproxy record of paleoclimates over the past three million years in west-central Yukon Terri-tory is emerging from numerous studies of fossil pollen, plants, and animals. As a part of the Late Cenozoic geology component of the ongoing Ancient Pacific Margin NATMAPProject, organic-rich sediments over-lying fluvial gravel have been routinely sampled in the south Klondike placer district to further detail this proxy record. Although several sites yielded rich assemblages of plant and invertebrate and vertebrate re-mains, only the Eddas Bench site along Thistle Creek yielded a datable record extending to the early Pleisto-cene. At least one Early Pleistocene glacial to interglacial cycle is recorded within it. A multidisciplinary investigation is underway.