The contribution of bacteria to organic matter in coal-measure source rocks

作     者：Qingsong Cheng Min Zhang Guanghui Huang Wenjun Zhang 

作者机构：College of Resources and Environment Yangtze University Key Laboratory of Exploration Technology for Oil & Gas Research (Yangtze University) Ministry of Education Bohai Petroleum Research Institute CNOOC (China) Co.Ltd.Tianjin Branch 

出 版 物：《Acta Geochimica》 (地球化学学报（英文）)

年 卷 期：2019年第38卷第3期

页      面：364-375页

核心收录：

学科分类：07[理学] 

基　　金：financially supported by the National Natural Science Foundation of China (No. 41772124) National Science and Technology Major Project (No. 2016ZX05007001-002) 

主　　题：Coal-measure source rocks Organic matter type Bacteria Monomethyl alkanes Alkyl cyclohexane 

摘      要：On the basis of GC–MS analysis, a suite of nine coal-measure source rocks(Ro 0.51%–0.63%) from the southern margin of Junggar basin was found to contain many biomarkers for bacterially-generated hydrocarbons:hopane, sesquiterpene, C_(23)+ monomethyl alkanes(even carbon predominance), and C_(24)+ alkyl ***–eval and microscope analysis indicate that vitrinite(especially desmocollinite and homocollinite) plays a significant role in the generation of hydrocarbons in coalmeasure source rocks. Vitrinite performs this role by absorbing ultramicroscopic organic matter, generally in the form of resins or bacterial plastids. C_(23)+ monomethyl alkanes(even carbon predominance) and C_(24)+ alkyl cyclohexane series compounds are derived from bacterial metabolites of higher plants. The ultramicro organic matter adsorbed by vitrinite source rocks in the study area is probably ultramicro bacterial plastids. Because the organic matter of higher plants with low hydrogen content has been transformed into organic matter rich in hydrogen by bacteria, the hydrocarbon generation capacity of source rocks is greatly improved. In other words, in coal-measure source rocks, bacteria play an important role in hydrocarbon generation.