Late Quaternary lake records from the Anadyr Lowland, Central Chukotka (Russia)

Abstract

Three lake cores provide insight into the vegetation and climate history of the past ∼45,000 14C yr in the Anadyr Lowland, a key paleogeographic link between the Bering Land Bridge (BLB) and interior Western Beringia (WB). Although not without chronological issues, these records suggest that the Late Pleistocene interstade (approximating Oxygen Isotope Stage (OIS) 3) was a time of unstable environments consistent with previous interpretations for southern areas of WB and in contrast to more stable conditions inferred for northern WB. A hiatus in the records during OIS2 implies dry, frigid environments in the Anadyr Lowland. Previous research suggested that Chuktoka was a westward extension of relatively mesic environments of the BLB, which acted as a “filter” to intercontinental migrations. The Lowland data indicate that Chukotka may have been more of a transitional zone between mesic BLB and more xeric regions of western WB. A structurally novel biome dominated by deciduous forest and high-shrub tundra was proposed as occupying much of Beringia between ∼11,000 and 9000 14C yr BP. The unusual pollen assemblage that characterizes the Lowland suggests that perhaps a second biome was also present in Beringia, one that was dominated by meadows with Betula shrub thickets.