Late Glacial and Holocene environmental change reconstructed from floodplain and aeolian sediments near Burdukovo, lower Selenga River Valley (Lake Baikal region), Siberia

Floodplain and aeolian sediments near Burdukovo reveal a detailed record of Holocene environmental change in the lower Selenga River Valley (Lake Baikal region, Siberia). During the late Pleistocene and early Holocene fine-grained alluvium accumulated on the floodplain followed by a period of increased landform stability and subsequent pedogenic formation. This part of the stratigraphical sequence yielded rich assemblages of terrestrial molluscs, which increase in species diversity from early pioneer communities with about ten taxa to levels containing over twice that number. The land snail assemblages also record an episode of relatively drier local habitats prior to ∼9.2 ka BP with subsequent wetter conditions lasting until ∼8.0 ka BP. This was followed by an abrupt and sustained change in floodplain deposition, shifting from overbank alluvium to aeolian sedimentation, within which a series of weakly developed soil horizons formed during the middle and late Holocene periods. The onset of aeolian processes and relatively drier conditions in the middle Holocene at Burdukovo coincides with major changes observed both in other regional palaeoenvironmental proxy records and in local archaeological sequences, although it is still not clear how the two are linked.