Quaternary paleosols, tephra deposits and landscape history in South Kamchatka, Russia

Paleosols developed in various glacial and glaciofluvial deposits of potentially different ages in the southern Kamchatka peninsula of Russia are covered by multiple layers of volcanic ash and have been affected by permafrost. Weathering indices and iron fractionation data indicate slight differences in soil development between the paleosols on terminal moraines and associated terraces of two different ages in the central part of the region, suggesting that the two depositional phases were separated by an interstadial rather than an interglacial. According to the extent of weathering and the age of the oldest tephra overlying the paleosols (ca. 8000 BP), both sets of deposits are of Late Pleistocene age. Glacial deposits on the west coast of the peninsula differ from those on the east in containing ice-wedge casts. Also, the paleosol here is less developed and is covered by lake sediments as well as tephra units. The oldest tephra, dated to ca. 40,000 BP, is present only in the west, suggesting that the western glacial deposits date from an older (Middle Pleistocene?) glaciation.