朝阳盆地白垩系九佛堂组火山沉积作用及其对有机质富集的影响  

Volcanic sedimentation of Cretaceous Jiufotang Formation in the Chaoyang Basin and its impact on organic matter enrichment

作　　者：张家志 姜在兴[1] 徐杰 魏思源 宋立舟 刘桐 沈志晗 姜晓龙 李永飞[5,6] 张玺 ZHANG Jiazhi;JIANG Zaixing;XU Jie;WEI Siyuan;SONG Lizhou;LIU Tong;SHEN Zhihan;JIANG Xiaolong;LI Yongfei;ZHANG Xi(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China;Daqing Oilfield Production Technology Institute,Daqing 163000,China;Beijing Yalong Technology Development Co.,Ltd.,Beijing 100096,China;Shenyang Geological Survey Center,China Geological Survey,Shenyang 110034,China;MNR Observation and Research Station of Mesozoic Stratigraphic System in Western Liaoning,Shenyang 110034,China;Exploration and Development Research Institute,Northeast Oil&Gas Branch,SINOPEC,Changchun 130062,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国地质大学(北京)海洋学院,北京100083 [3]大庆油田采油工程研究院,黑龙江大庆163000 [4]北京亚隆科技发展有限公司,北京100096 [5]中国地质调查局沈阳地质调查中心,辽宁沈阳110034 [6]自然资源部辽西中生代地层系统野外科学观测研究站,辽宁沈阳110034 [7]中国石化东北油气分公司勘探开发研究院,吉林长春130062

出　　处：《地学前缘》2024年第3期284-297,共14页Earth Science Frontiers

基　　金：国家自然科学青年基金项目“塔里木大火成岩省溢流玄武岩与辉绿岩墙的岩浆源区与演化(41803023)”。

摘　　要：辽西朝阳盆地位于燕山构造带东段,属于松辽外围中生代的断陷盆地,勘探认识程度不高。前人研究认为,朝阳盆地下白垩统九佛堂组为湖相沉积,而忽略了火山事件对于湖盆沉积的重要影响。对此笔者通过区域地质资料调查、钻井岩心描述、岩心薄片资料观察以及分析测试资料等手段,在火山碎屑岩分类基础上,根据火山碎屑含量划分出沉积火山碎屑岩以及火山碎屑沉积岩,并结合粒度、组分、沉积构造等特征细分出11种岩相类型以及9种岩相组合,进而提出火山碎屑流、火山异重流、火山灰异轻流、热液侵入和微生物诱导5种成因机制。结合钻井岩心观察识别出火山沉积序列及沉积特征,建立了朝阳盆地九佛堂组火山湖泊沉积模式,为研究区油气资源的勘探开发提供理论依据。研究发现,火山物质对湖盆内有机质富集起到积极的影响。朝阳盆地九佛堂组烃源岩地化测试显示:含有火山细粒物质参与沉积的样品有机质丰度指标更好,有机质更富集。由于燕山构造带内其他盆地同样具有相似的火山活动地质背景,研究结果也为这些地区沉积学及油气资源研究起到良好的对比参照作用。The Chaoyang Basin in western Liaoning,situated in the eastern section of the Yanshan tectonic belt,is a fault basin from the Mesozoic era on the periphery of Songliao.The level of exploration understanding in this region is relatively low.Previous studies on the Lower Cretaceous Jiufotang Formation in the Chaoyang Basin primarily focused on lacustrine deposits,overlooking the significant impact of volcanic events on the basin s sedimentation.To address this gap,regional geological data investigation,drilling core description,core thin section data observation,and test data analysis were conducted.By classifying pyroclastic rocks into sedimentary pyroclastic rocks and pyroclastic sedimentary rocks based on their content and subdividing them into 11 lithofacies types and 9 lithofacies combinations according to particle size,composition,and sedimentary structure characteristics,five causal mechanisms were proposed:pyroclastic flow,volcanic hyperpycnal flow,volcanic ash heterogeneous light flow,hydrothermal intrusion,and microbial induction.The establishment of the volcanic-lake sedimentary model of the Jiufotang Formation in the Chaoyang Basin,based on volcanic sedimentary sequences and core observation findings,offers a theoretical foundation for oil and gas resource exploration and development in the area.Research indicates that volcanic material positively influences organic matter enrichment in the lake basin.Geochemical tests on source rocks of the Jiufotang Formation in the Chaoyang Basin revealed that samples containing volcanic fine particles involved in sedimentation exhibited better organic matter abundance and enrichment.Given the similar volcanic activity geological background in other basins within the Yanshan tectonic belt,these findings also serve as valuable comparative references for sedimentology and oil and gas resource research in those regions.

关 键 词：朝阳盆地 九佛堂组 岩相类型及组合 成因机制 有机质富集 

分 类 号：P588.211[天文地球—岩石学] P618.130.21[天文地球—地质学] P539.6