Identification of the Kukersite-type source rocks in the Ordovician Stratigraphy from the Tarim Basin, NW China  

作　　者：SUN YongGe MAO ShengYi WANG FeiYu PENG PingAn CHAI PingXia 

机构地区：[1]State Key Laboratory of Organic Chemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences [2]Department of Earth science, Zhejiang University [3]University of Chinese Academy of Sciences [4]Department of Geosciences, China University of Petroleum (Beijing)

出　　处：《Chinese Science Bulletin》2013年第35期4450-4458,共9页

基　　金：supported by the National Oil and Gas Special Fund of China(2011ZX05008-002-15);the National Natural Science Foundation ofChina(41172112)

摘　　要：Due to the importance of the Gloeocapsomorpha Prisca(G.prisca)-enriched source rocks,which belong to Kukersite-type source rocks in the Lower Paleozoic Ordovician strata,it has received great attentions during the petroleum exploration as to whether there are the Kukersite-type source rocks developed in the major hydrocarbon source strata of the Upper and Middle Ordovician in the Tarim Basin.Using pyrolysis-gas chromatography-mass spectrography to analyse kerogens from source rocks in the limemud mound with moderate maturity,study reveals that there are the Kukersite-type source rocks in the Ordovician strata of the Tarim Basin.The pyrolysis products showed a low content of>n-C19normal alkanes with a significant odd-even predominance between n-C13and n-C17,long-chain alky substituted alkylbenzene and alkylthiophene isomers and distinctive distribution of 5-Nalkyl-1,3-Benzenediol and its homologous.Based on the geographic environment characteristics of G.Prisca,the molecular distributions of crude oil from the Lower Paleozoic petroleum systems in the Tarim Basin and characteristics of kerogen pyrolysis products from the Middle and Upper Ordovician source rocks,the results suggested that it is less possible to develop the G.Prisca-enriched Kukersite-type source rocks in the major hydrocarbon source rocks in the Middle and Upper Ordovician strata in the Tarim Basin.However,the benthic macroalga and planktonic algae-enriched source rocks are the main contributors.Due to the importance of the Gloeocapsomorpha Prisca （G. prisca）-enriched source rocks, which belong to Kukersite-type source rocks in the Lower Paleozoic Ordovician strata, it has received great attentions during the petroleum exploration as to whether there are the Kukersite-type source rocks developed in the major hydrocarbon source strata of the Upper and Middle Ordovician in the Tarim Basin. Using pyrolysis-gas chromatography-mass spectrography to analyse kerogens from source rocks in the lime- mud mound with moderate maturity, study reveals that there are the Kukersite-type source rocks in the Ordovician strata of the Tarim Basin. The pyrolysis products showed a low content of 〉n-C19 normal alkanes with a significant odd-even predominance between n-C13 and n-Cl7, long-chain alky substituted alkylbenzene and alkylthiophene isomers and distinctive distribution of 5-N- alkyl-1, 3-Benzenediol and its homologous. Based on the geographic environment characteristics of G. Prisca, the molecular dis- tributions of crude oil from the Lower Paleozoic petroleum systems in the Tarim Basin and characteristics of kerogen pyrolysis products from the Middle and Upper Ordovician source rocks, the results suggested that it is less possible to develop the G. Pris- ca-enriched Kukersite-type source rocks in the major hydrocarbon source rocks in the Middle and Upper Ordovician strata in the Tarim Basin. However, the benthic macroalga and planktonic algae-enriched source rocks are the main contributors.

关 键 词：塔里木盆地 奥陶纪地层 烃源岩 e型 鉴定 中国 裂解气相色谱 下古生界 

分 类 号：P618.13[天文地球—矿床学]