泥炭分子化石单体碳氢同位素的古气候意义  

Paleoclimate Implication from Compound-Specific δ^(13)C and δD of Molecular Fossils in Peat Deposits

作　　者：谢树成[1] 易轶[1] 梁斌[1] 郭建秋[1] Richard P.Evershed 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]School of Chemistry,University of Bristol

出　　处：《矿物岩石地球化学通报》2003年第1期8-13,共6页Bulletin of Mineralogy, Petrology and Geochemistry

摘　　要：为了查明泥炭分子化石记录的古植被状况与古植物学分析结果的差异,并进一步探讨这些分子化石所记录的古气候信息,本文利用气相色谱仪(GC)、气相色谱 质谱联用仪(GC MS)、气相色谱 燃烧 同位素比质谱仪(GC C IRMS)、气相色谱 热转换 同位素比质谱仪(GC TC IRMS)详细分析了一个40cm(约220年)长的泥炭岩芯中的分子化石及其单体碳、氢同位素组成。正构烷烃分子化石的主峰化合物(C23)及其碳、氢同位素组成与温度有很好的对应关系,工业革命以来化石燃料的燃烧效应也在单体碳同位素上反映出来。这些结果反映了泥炭分子化石具有很好的古气候和古环境意义。It is known that peat deposits have the potential in the reconstruction of paleoclimate and paleovegetation, though deviation between molecular fossils and paleobotany record was reported previously. In order to elucidate this deviation and to extract the paleoclimate signals, molecular fossil distribution and compoundspecific δ13C and δD in a 40?cm long (spanning 220 years) peat deposit in England were systematically investigated through the analyses of gas chromatography (GC), GCmass spectrometry (MS), GCcombustionisotope ratio MS (IRMS) and GCthermal conversionIRMS. The maximum compound of nalkanes and its δ13C and δD values display a similar trend with the documentary record of summer temperature in England in recent 200 years. Anthropologic activity including the fossil fuel combustion also left an imprint in the compoundspecific δ13C values. This preliminary result shows the potential to use the peat molecular fossils as paleoclimate proxy.

关 键 词：碳同位素 氢同位素 古气候 生物标志化合物 泥炭分子化石 古环境 温度 

分 类 号：P593[天文地球—地球化学]