鄂尔多斯盆地侏罗系延安组源-汇系统特征及古地理格局  

Characteristics and paleogeographic pattern of source-to-sink system of the Jurassic Yan’an Formation in Ordos Basin

作　　者：袁珍 司豪杰[1,2] 马瑶 陈立军 郭艳琴[1,2] 孙楠[1,2] YUAN Zhen;SI Haojie;MA Yao;CHEN Lijun;GUO Yanqin;SUN Nan(School of Earth Science and Engineering,Xi’an Shi You University,Xi’an 710065,China;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an Shi You University,Xi’an 710065,China;Exploration and Development Technology Research Center of Yanchang Oilfield Co.,Ltd.,Yan’an 718500,China)

机构地区：[1]西安石油大学地球科学与工程学院,陕西西安710065 [2]西安石油大学陕西省油气成藏地质学重点实验室,陕西西安710065 [3]延长油田股份有限公司勘探开发技术研究中心,陕西延安718500

出　　处：《西北大学学报（自然科学版）》2024年第6期1104-1120,共17页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省重点研发计划一般项目(2023-YBGY-079)。

摘　　要：鄂尔多斯盆地中侏罗统延安组是印支运动后滞效应后,受周缘造山带多物源系统影响的一套含煤碎屑岩地层,煤炭及油气等资源勘探潜力巨大。通过轻矿物、重矿物、古流向、主微量及稀土元素等进行物源分析,结合前人研究成果,开展了盆地延安组源-汇系统特征研究。结果表明,盆地延安组受来自北部阴山古陆、西北部阿拉善古陆、西南部祁连古陆及南部北秦岭造山带4个源-汇系统的影响。在源-汇系统分区的基础上深化了古地理格局认识,延安组在前侏罗纪沟壑纵横的地貌基础上,受4个不同古陆风化剥蚀搬运沉积过程差异的影响,形成了以盆地中部延安—东南部济源地区为沉积中心的陆相含煤碎屑岩沉积,自盆地边缘至汇水区,冲积扇-辫状河-曲流河-三角洲-湖泊沉积有序变化,其中以西北、北部源-汇系统沉积规模最大,是盆地勘探重点。研究结果对于深入理解不同物源体系影响下的各类储层特征及储层预测等具有理论和现实意义。The middle-Jurassic Yan’an Formation in Ordos Basin is a set of coal-bearing clastic strata influenced by multiple source systems of the peripheral orogenic belt after the lag effect of the Indosinian movement.The coal and oil-gas resources show great exploration potential.This paper investigates the provenance analysis based on the characteristics of light minerals,heavy minerals,paleo-flow,major,trace and rare earth elements.And the characteristics of source-to-sink system of Yan’an Formation in Ordos Basin are studied based on previous research results.The result shows that the Yan’an Formation in Ordos Basin is influenced by four source-to-sink systems from Yinshan ancient land in the north,Alxa ancient land in the northwest,Qilian ancient land in the southwest and north Qinling orogenic belt in the south.This paper deepens the understanding of paleogeographic pattern on the basis of source-to-sink system partition:on the basis of the ravines crossbar landform in the pre-Jurassic period,the Yan’an Formation was influenced by the difference of weathering,denudation-transport and deposition processes in four different ancient terrigenous source areas.Yan’an Formation formed continental coal-bearing clastic rock deposits with Yan’an in the middle-Jiyuan in the southeast as the depositional center.Alluvial fan-braided river-meander river-delta-lake deposition changes from basin margin to catchment area in an orderly manner.The northwestern and northern source-to-sink system has the largest sedimentary scale.And it is the focus of basin exploration.It is concluded that the results have theoretical and practical significance for further understanding of various reservoir characteristics and reservoir prediction under the influence of different provenance systems.

关 键 词：源-汇系统 古地理格局 延安组 鄂尔多斯盆地 

分 类 号：P512.2[天文地球—地质学]