通过C_(27)/C_(29)甾烷和有机碳同位素来判断早古生代和前寒武纪的烃源岩的生物来源  

BIOLOGICAL ORIGIN OF EARLY PALAEOZOIC AND PRECAMBRIAN HYDROCARBON SOURCE ROCKS BASED ON C_(27)/C_(29) STERANE RATIO AND ORGANIC CARBON ISOTOPE

作　　者：孟凡巍[1] 周传明[1] 燕夔[1] 袁训来[1] 尹磊明[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008

出　　处：《微体古生物学报》2006年第1期51-56,共6页Acta Micropalaeontologica Sinica

基　　金：国家自然科学基金(批准号:40472003;40372006);科学技术部重大国际合作项目(2003CB716805);国家重点基础研究发展规划项目(G2000077701);中国科学院知识创新项目(KZCXSW141)资助。

摘　　要：在早古生代与前寒武纪的石油与源岩中,经常出现令人困惑的C29甾烷优势,而在有机地球化学中C29甾烷优势被认为是陆相有机质输入的标志。作者通过对比文献中各种海相藻类的热模拟产物分析,提出了早古生代与前寒武纪的石油与源岩中C29甾烷优势主要来源于浮游绿藻的观点,并通过C27甾烷/C29甾烷的比值提出了区分早古生代及前寒武纪石油源岩沉积环境的方法,对中国南方前寒武纪和早寒武世黑色岩系的有机地球化学分析也支持上述推断。此外,本文还提出了用有机碳同位素来进一步区分C29甾烷优势生物来源的方法。The predominance of C29 sterane in early Paleozoie and Preeambrian rocks and crude oils is puzzling, because the predominance of C29 sterane is often taken as the result of high terrestrial plant input. Based on mainly the previously published investigations on various algae pyrolytic products , we proposed that the predominance of C29 sterane in early Paleozoic and Precambrian source rocks and crude oils may have come from planktonic green algae, and the different sedimentary environments can be distinguished through C27/C29 sterane ratios. The organic geochemistry results of Precambrian and early Cambrian black shales from South China support this conclusion. We also bring forward a new method to recognize the different biological source for C29 sterane predominance using organic carbon isotope.

关 键 词：C29 甾烷优势 生物来源 早古生代 前寒武纪 

分 类 号：P618.13[天文地球—矿床学]