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The trace molecular fossils identified in the Pleistocene vermicular red earth by using the gas chromatography-mass spectrometry (GC/MS) analysis include n-alkanes, n-alkanoic acids, n-alkanols and n-alkan-2-ones. The variations of the n-alkane parameters appear to bear signifi-cant climate information, in striking contrast to the oxygen-bearing molecules (n-alkanoic acids and n-alkanols) believed to be more easily reworked by post-depositional processes. Of importance in paleoclimate reconstruction are the ratios of C27/C31 n-alkane indicative of the replacement of woody plants by grassy vegetation, and C15—21/C22—33 n-alkane representative of the relative abun-dance between microorganisms and higher plants. The profile trends of the two n-alkane ratios are comparable to the marine oxygen isotope record among stages 4—20. These molecular fossil re-cords implicate that the Pleistocene vermicular red earth widespread in South China was formed in coupling to the global climatic change and could be an important climate carrier.
The trace molecular fossils identified in the Pleistocene vermicular red earth by using the gas chromatography-mass spectrometry (GC / MS) analysis include n-alkanes, n-alkanoic acids, n-alkanols and n-alkan-2-ones. the n-alkane parameters appear to bear signifi-cant climate information, in striking contrast to the oxygen-bearing molecules (n-alkanoic acids and n-alkanols) believed to be more easily reworked by post-depositional processes. Of importance in paleoclimate reconstruction are the ratios of C27 / C31 n-alkane indicative of the replacement of woody plants by grassy vegetation, and C15-21 / C22-33 n-alkane representative of the relative abun-dance between microorganisms and higher plants. The profile trends of the Two molecular alkane ratios are comparable to the marine oxygen isotope record among stages 4-20. These molecular fossil re-cords implicate that the Pleistocene vermicular red earth widespread in South China was formed in coupling to the global climatic cha nge and could be an important climate carrier.