Geochemical features of organic components in lake sediments and algal mats from the Lützow-Holm Bay region, Antarctica

Summary

Geochemical features of hydrocarbons and fatty acids in lake and pond sediments from the Lützow-Holm Bay region, Antarctica were studied in relation to source organisms. Unusually, long-chain n-alkanes and n-alkanoic acids (> C₁₉) were detected in certain samples, together with short-chain alkanes and alkenes, and alkenoic and branched acids. Also, triterpenes, such as hop-22(29)- ene and steranes were found in some samples. These compounds may be derived form diatoms, green algae and/or cyanobacteria, with some influences of bacteria. However, the specific organisms are not yet clear. Further biogeochemical and physiological studies of pure cultured Antarctic algal and cyanobacterial mat communities should be fruitful. Normal alkenoic acid/n-alkanoic acid ratios are probably reflecting the degree of destruction of organic matter.