Biomarkers and the related global change

Biomarkers occurring at a variety of geological environments have been shown to be effective in the exploitation of past global changes. Reconstructions of paleo vegetation, paleo temperature, paleo precipitation, paleo atmospheric CO2 concentration, paleo monsoon were conducted in various sediments using the distributions and isotopic compositions of biomarkers. Here we present a 40cm long peat record based on the analyses of biomarker distribution and compound specific δ D using gas chromatography (GC), GC mass spectrometry (MS) and GC thermal conversion isotope ratio MS. The preliminary result shows that both the distribution and isotope composition of biomarkers are capable of reflecting the variations of paleoclimate. Specifically, The profile trends of the carbon preference index of n alkanoic acids, the ratio of C 23 /C31 n alkanes and δ D of C23 n alkane are comparable with the documented temperature record of the period the peat core spans