广西崇左柳桥地区上二叠统礁灰岩中沥青的地球化学特征

Geochemical characteristics of bitumen in the Upper Permian reef limestone in Liuqiao(Chongzuo)area,Guangxi province

邱振 王清晨 贾望鲁 韦恒叶 彭平安

Qiu Zhen Wang Qingchen Jia Wanglu Wei Hengye Peng Pingan

广西崇左柳桥地区上二叠统生物礁灰岩中普遍发育沥青,沥青主要充填于生物礁内的溶蚀孔洞和裂隙中,其次在生物体腔内。研究区内上二叠统沥青的成熟度较高,H/C原子比一般小于0.1。对崇左柳桥地区上二叠统生物礁灰岩中的沥青和大隆组的硅质岩、硅质泥岩等进行饱和烃色谱-质谱分析,综合对比其所含直链烷烃、萜烷、藿烷、甾烷和生物标志物。结果表明,这些上二叠统沥青源自大隆组的可能性不大,但可能来源于泥盆系烃源岩。

Bitumen are well developed in the Upper Permian reef limestone in Liuqiao area,Chongzuo,Guangxi province,and they mainly occur in the cavities and fractures of bioherms,followed by biological coelomata.The bitumen samples show a high maturity and an atomic ratio of H/C generally less than 0.1.Based on the gas chromatography-mass spectrometry analyses of saturated hydrocarbon extracted from the bitumen in the Upper Permian as well as from the silicite and and siliceous mudstones in the Dalong Formation in the Liuqiao(Chongzuo)area,we correlated their -alkane,terpane,hopane,sterane and biomarkers.The result shows that the possibility of the bitumen being sourced from the Dalong Formation of the Upper Permian is slime.Instead,it could come from the source rocks of the Devonian in the study area.

10.11743/ogg20120603