南京大学学报：自然科学版2012，Vol.48Issue(3)：295-307,13.
大巴山造山过程有机流体研究
Features and formation of organic fluids during Dabashan orogenesis
摘要
Abstract
Field investigations along with detailed petrographic observations show that plentiful organic fluids with different characteristics and various occurrences developed in different tectonic units in the Dabashan foreland belt. Large amounts of organic fluids inclusions together with metamorphic fluid inclusions were found in the northern Dabashan thrust-nappe belt. However, organic fluids in the Dabashan foreland belt and the foreland depression were marked with three stages of organic fluid inclusions： the earliest stage of liquid hydrocarbon inclusions, the intermediate stage of pure gaseous hydrocarbon inclusions and the last stage of solid bitumen inclusions. Tbesethree stages organic fluid inclusions recorded formation and evolution history of oil/gas during orogenesis of Dabashan foreland bell. Isotopic analysis to fluid inclusions contained by calcite veins filled in fractures show that δ^13 Ci of organic gas in fluid inclusion was --17. 036‰ -- 30. 390‰ and δD was --107.712‰--156.730‰, which indicated that the gas captured by veins was migrated natural gas. Organic geochemical analysis to bitumen with different occurrences indicated that original organic matter of bitumen in Dabashan foreland belt was mainly the lower aquatic organisms and algae. Lower Cambrian carbonaceous mudstone and Lower Permian carbonate were the most possible source rocks of bitumen. Combined with tectonic evolution history of Dabashan foreland belt, this research proposed that liquid oil was generated from the Paleozoic source rocks in Dabashan area under normal burial thermal conditions before lndosinian orogeny hut accumulated to form paleo reservoirs during Indosinian collision between the North China block and the Yangtze block. The paleo reservoir was destroyed to become reservoir bitumen during Yanshan tectonic when Dabashan foreland belt formed. At the same time, liquid oil in Dabashan foreland depression was pyrolyzed to transform co natural gas. It indicated that there was not only natural gas hut also liquid oil formed and accumulated during Dabashan orogenesis.关键词
有机流体/有机包裹体/沥青/前陆构造/大巴山Key words
organic fluid/bitumen/fluid inclusion/orogeny/Dabashan foreland分类
地质学引用本文复制引用
李荣西,董树文,张少妮,朱瑞静,夏彬..大巴山造山过程有机流体研究[J].南京大学学报：自然科学版,2012,48(3):295-307,13.基金项目
基金项目：国家自然科学基金（41173055）,国家地质调查项目 （）
