近海断陷盆地古近纪煤系沉积控煤作用与成煤模式--以山东黄县盆地为例  

Sedimentary coal-controlling effect and coal-forming model of Paleogene coal measures in paralic faulted basin:A case study of Huangxian Basin,Shandong Province

作　　者：吴悦 王东东 王海亮 刘海燕 李增学 郑雪 WU Yue;WANG Dongdong;WANG Hailiang;LIU Haiyan;LI Zengxue;ZHENG Xue(College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Longkou Mining Group Engineering Construction Co.,LTD.,Yantai 265700,China;Library,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学地球科学与工程学院,山东青岛266590 [2]龙口矿业集团工程建设有限公司,山东烟台265700 [3]山东科技大学图书馆,山东青岛266590

出　　处：《煤田地质与勘探》2023年第4期23-36,共14页Coal Geology & Exploration

基　　金：中海油研究总院委托项目(CCL2021RCPS0172KQN);国家自然科学基金项目(42072188,42272205);河北省资源勘测研究重点实验室开放基金。

摘　　要：我国海域区煤型油气资源量丰富,然而海域煤型烃源岩的研究程度却相对较低,严重制约了海域区煤型油气资源勘探。选取与海域区煤盆地成煤时代基本一致、地质条件相似、研究程度高的近海断陷含煤盆地——黄县盆地为例,开展沉积控煤作用与成煤模式研究。在充分吸取前人研究成果的基础上,精细重建了成煤期的古地理格局、演化及其沉积控煤作用。结果表明:(1)黄县盆地古近纪煤系主要发育冲积扇、扇三角洲、辫状河三角洲和湖泊沉积,可以识别出2个三级层序。煤层主要发育在湖扩张体系域时期的辫状河三角洲、滨浅湖环境。(2)综合恢复了涵盖古近系整个成煤过程的层序I湖扩张体系域和高水位体系域、层序II低水位体系域和湖扩张体系域的层序−古地理格局,并分析其沉积演化特征与沉积控煤作用;煤层主要发育在低水位体系域晚期−湖扩张体系域早期,湖平面缓慢上升的辫状河三角洲前部湖沼环境,并逐步向辫状河三角洲扩展;其次,煤层发育在湖扩张体系域的中晚期,湖平面频繁变浅−变深的湖沼−浅湖沉积环境。(3)建立了古近纪近海断陷盆地2种典型的沉积成煤模式。一是滨浅湖湖沼−辫状河三角洲成煤模式,主要发育在低水位体系域晚期−湖扩张体系域早期湖水平面缓慢抬升的过程,煤层厚度较大但分布相对局限,如煤4、煤2。二是滨浅湖湖沼−浅湖成煤模式,主要发育在湖扩张体系域中−晚期湖平面下降−上升的过程中;湖平面升降频繁导致成煤环境频繁出现−消失,形成的煤层厚度较小但分布较广,如煤1、煤上1等。本研究阐明的近海断陷盆地煤层发育规律和建立的沉积成煤模式,将为海域区煤型烃源岩勘探提供一定的理论支持。There are abundant coal-type oil and gas resources in Chinese sea area,but few researches have been conducted on the coal-type source rock,which seriously restricts the exploration of coal-type oil and gas resources in the sea WU Yue,WANG Dongdong,WANG Hailiang,et al.Sedimentary coal-controlling effect and coal-forming model of Paleogene coal measures in paralic faulted basin:A case study of Huangxian Basin,Shandong Province[J].Coal Geology&Exploration,2023,51(4):23−36.doi:10.12363/issn.1001-1986.22.10.0794 area.Herein,this study on sedimentary coal-controlling effect and coal-forming model was carried out based on Huangxian Basin that is a paralic faulted basin with same coal-forming period,similar geological conditions and high degree of research for the coal basins in the sea area.Specifically,the pattern,evolution and sedimentary coal-controlling effect of paleogeography during the coal-forming period were reconstructed with full consideration to the previous research results.The results show that:(1)alluvial fan,fan delta,braided river delta and lacustrine deposit are mainly developed in the Paleogene coal measures in Huangxian Basin,where two third-order sequences can be identified.Definitely,the coal seam is mainly developed in the braided river delta and shore-shallow lacustrine environment during the lake expansion systems tract(EST).(2)The sequence-paleogeographic pattern of the EST and high-stand systems tract(HST)in sequence I,as well as the low-stand systems tract(LST)and EST in sequence II,covering the whole coal-forming process of Paleogene was comprehensively reconstructed.Meanwhile,the sedimentary evolution characteristics and sedimentary coal-controlling effect were analyzed.The coal seam is mainly developed in the late LST-early EST and the lacustrine bog environment in the front of braided river delta with the lake level rising slowly,and gradually expanded to the braided river delta.Besides,the coal seam is mainly developed in the middle and late EST,and the shallow lake sedimentary environ

关 键 词：层序−古地理 沉积控煤作用 成煤作用 黄县盆地 古近纪 

分 类 号：P531[天文地球—古生物学与地层学]