Freshwater ostracodes in Quaternary permafrost deposits from the Siberian Arctic

Ostracode analysis was carried out on samples from ice-rich permafrost deposits obtained on the BykovskyPeninsula (Laptev Sea).A composite pro file was investigated that covers most of a 38-m thick permafrostsequence and corresponds to the last ca.60 kyr of the Late Quaternary.The ostracode assemblages aresimilar to those known from European Quaternary lake deposits during cold stages.The ostracode habitatswere small,shallow,cold,oligotrophic pools located in low centred ice wedge polygons or in small ther-mokarst depressions.In total,15 taxa,representing 7 genera,were identi fied from 65 samples.The studiedsection is subdivided into six ostracode zones that correspond to Late Quaternary climatic and environ-mental stadial-interstadial variations established by other paleoenvironmental proxies:(1)cold and dryZyrianian stadial (58 53 kyr BP);(2)warm and dry Karginian interstadial (48 34 kyr BP);(3)transitionfrom the Karginian interstadial to the cold and dry Sartanian stadial (34 21 kyr BP);(4)transition fromthe Sartanian stadial to the warm and dry Late Pleistocene period,the Allerød (21 14 kyr BP);(5)transition from the Allerød to the warm and wet Middle Holocene (14 7 kyr BP);and (6)cool and wetLate Holocene (ca.3 kyr BP).The abundance and diversity of the ostracodes will be used as an additionalbioindicator for paleoenvironmental reconstructions of the Siberian Arctic