Molecular organic geochemical peculiarities of lacustrine core sediments in Fildes Peninsula, King George Island, Antarctica

The peculiarities of lipids in lacustrine core sediments from Fildes Penins ula, King George Island, Antarctica, are reported. The origin of high-molec ular-weight n-alkanes, alkenes, fatty acids, alcohols is supposed to be rel ated to the abundant moss occurring in the sediments. Abundant iso- and ant eiso-fatty acids that occur in the sediments indicate a relatively strong b acterial activity in non-ice-cover zone than in other regions in Antarctica . The C-18:2 unsaturated fatty acids mainly originate from autochthonous al gae in the sediment pool, and the C-18:2/C-18:0 ratios in the profile are c ontrolled more by paleotemperatures than source assemblies. Long-chain alke nones were identified in freshwater lacustrine sediment in Antarctica for t he first time, of which Prymnesiophyceae is assumed to be the source organi sm. High relative abundance of C-37:4 homologue in long-chain alkenone well correlates to the severely cold climate in Antarctica.