羌塘盆地羌资3井索瓦组泥岩生物标志化合物特征及其地质意义合编.docx

羌塘盆地羌资3井索瓦组泥岩生物标志化合物特征及其地质意义杜佰伟彭清华何江林中国地质调查局成都地质调查中心成都 610081摘要：本文对羌塘盆地羌资3井索瓦组样品开展了详细的有机地球化学特征研究，探讨了其有机母质来源及形成的沉积环境。样品中检测出丰富的正构烷烃、类异戊二烯烷烃、萜类化合物和甾类化合物。在GC图谱上，主碳数分别为nC17、nC18、nC23或nC25, OEP值为0.4-1.24, Pr/nC17值为0.68～0.99、Ph/ nC18值为0.55～0.98 ,Pr/Ph为0.50~0.90。萜类化合物以C30藿烷占优势的五环三萜烷为主，含有三环萜烷和伽马蜡烷。甾类化合物以规则甾烷为主，C27、C28和C29甾烷构成了不对称的“V”字型，C29ααα20S/（20S+20R)和C29αββ/ (ααα+αββ) 的值分别为0.30～0.49、0.40～0.54。饱和烃色谱/质谱特征表明泥岩有机母质来源来源于具有水生生物的混合来源，揭示了其母质形成于一定盐度缺氧还原环境。镜质体反射率与成熟度参数均显示泥岩与沥青处于生油高峰阶段。生物标志物研究显示羌资3井沥青与泥岩在母质性质、沉积环境、成熟度等方面有相近的特征，它们具有较好的亲缘关系。关键词：羌塘盆地，索瓦组，生物标志化合物，地质意义CHARACTERISTICS OF BIOMARKER COMPOUNDS ANDTHEIR geological significance IN THE UPPER JURASSIC MUDSTONEOF THE SUOWA FORMATION FROM QZ3 WELL IN THE QIANGTANG BASIN,THE NORTHERN TIBETDu baiweiPengqinghua HejianglinChengdu Center of China Geological Survey,Chengdu,Sichuan 610081, ChinaAbstract:This paper aims to develop detailed research on geochemical charactericsof the Suowa Formation ?mudstones from Well QZ3.The origin of organic matters and sedimentary environment have been discussed,according to the study of the characteristics of biomarkers. Abundant biomarkers,including n-alkanes,isoprenoid, terpanes and steranes from mudstones have been detected by GC and GC-MS. The n-alkanes have nC17、nC18、nC23or nC25 as the mean peaks. OEP values vary from 0.4 to 1.24，Pr/nC17 from 0.68 to 0.99, Ph/ nC18 from 0.55 to0.98, and Pr /Ph from 0.50 to 0.90. In the m/z191 GC-MS,C30 hopane is most abundant in the terpanes，tricyclic terpanes and gammacerane are present. In the m/z217 GC-MS, regular steranes are characterized by highest abundances. The regular steranes C27-C28-C29ααα20R distributes with asymmetric“V”shape. C29ααα20S/（20S+20R) values vary from 0.30 to 0.49 and C29αββ/ (ααα+αββ) from 0.40 to 0.54. GC/MS characteristics of saturated hydrocarbon show that organic matter is characterized by mixed sources which is constituted by phytoplankton,reveal that Organic matter forms in low-salinity?anoxic environment.Different kinds of p