Strontium isotopic composition in late Pleistocene mammal bones from the Yakutian region (North-Eastern Siberia)

Isotopic strontium composition of several bones, for which 14C data are available, retrieved from latest Pleistocene deposits of the Yakutian region has been analysed. Three different groups have been detected, corresponding to samples from great maritime (Yana-Indigirka interfluve, Kolymian lowland) lowlands covered by thick Pleistocene sediments, from areas where Palaeozoic and Precambrian complex and Mesozoic granites crop out, and from Arctic coasts and Siberian Islands. Preliminary results highlight the difficulty in discriminating among resident, temporary migrant or long-distance newcomers if the sampling is not consistent. Taking into account global changes of sea level, the Laptev Sea shelf was mainly drained during the sea level lowering in the Late Pleistocene. Herbivores, and especially mammoths, did not utilise this shelf pastures. Therefore, the results pose several questions: what is the reason for herbivores not visiting the shelf? Was the shelf occupied by other mammal populations whose remains lie on the sea bottom? Was the territory too boggy for large animals? Why did mammals prefer vegetation from inland over shelf landscapes? The ongoing research might clarify some issues.