A Postglacial Pollen Record from Western Kodiak Island, Alaska

Abstract

Excavation of organic deposits in a seasonally dry depression atop a moraine crest near the village of Karluk, on the west side of Kodiak Island, has provided a more detailed paleoenvironmental record than hitherto available for this part of the island. Radiocarbon dating indicates that the base of the section is approximately 4260 14C years in age. Seven minor volcanic ashes are recognized prior to the onset of seasonal drying of the basin at about 2330 B.P. A major ash fall (2 cm thick in section) is recorded at about 1625 B.P. The only significant woody taxon indicated in the pollen record is alder (Alnus); all other important taxa are herbaceous. This vegetation record indicates alders and ferns dominated the landscape immediately following substrate stabilization, which apparently was delayed in this area until well into the Holocene. Alder became relatively less important as soils matured and other taxa (mostly grasses) invaded. The overall record is one of vegetational and climatic stability since landscape stabilization in this area. Volcanic ashfalls have apparently had no significant long-term impact on the vegetation at the site.

Key words: Alaska, Holocene, Karluk, Kodiak Island, Quaternary, geology, glaciation, paleoenvironments, palynology, radiocarbon dating, tephra