石油实验地质2016，Vol.38Issue(5)：647-651,5.DOI:10.11781/sysydz201605647
鄂尔多斯盆地南缘奥陶系露头沥青地球化学特征与意义
Geochemical characteristics and significance of bitumen of Ordovician outcrops at the southern margin of Ordos Basin
摘要
Abstract
Outcrop bitumen occurs in the limestone cracks in the Lower Ordovician Liangjiashan Formation at the southern margin of Ordos Basin. The cracks are nearly vertical. The bitumen zone is about 75 m high and 1-44 cm wide, and is wide at the bottom and narrow on the top. The carbon isotope value of the bitumen is-28‰. Equivalent bitumen vitrinite reflectance ranges from 1.829%-1.965%. The bitumen and the source rocks in the Upper Ordovician Beiguoshan Formation have low Pr/Ph values and high C24 tetracyclic terpane biomarker concentrations. Bitumen sam⁃ples with C29 sterane predominance and low gammacerane index reveal that hydrocarbon parent materials were formed in a low⁃brackish water environment from marine plankton. The composition of steroids is“V” type, and the biomar⁃kers such as C24 tetracyclic terpanes/C26 tricyclic terpanes and Tm/Ts are similar, indicating a genetic relationship. The geochemical characteristics and significance of bitumen of the Ordovician outcrops at the southern margin of Ordos Basin have helpful for the evaluation of the Lower Paleozoic carbonate source rocks.关键词
露头沥青/生物标志物/地球化学特征/奥陶系/鄂尔多斯盆地南部Key words
outcrop bitumen/biomarker/geochemical feature/Ordovician/southern margin of Ordos Basin分类
能源科技引用本文复制引用
金晓辉,孙润轩,陈霞,孙宜朴,张军涛,李淑筠..鄂尔多斯盆地南缘奥陶系露头沥青地球化学特征与意义[J].石油实验地质,2016,38(5):647-651,5.基金项目
国家科技重大专项（2011ZX05005）和中国石化科技部项目（2014P1067）资助。 （）
