摘要
围绕浅海背景下大型浊积扇的研究进展展开探讨,并以莺歌海盆地黄流组重力流为例研究其沉积特征及堆积机制。位于莺歌海盆地中央的东方区黄流组发育的大型高效储集体——浅海重力流沉积体的沉积特征和堆积机制具有其独特性。古生物研究表明,其沉积期的古水深为40~110m,属于陆架浅水沉积背景。其重力流特征表现为包卷变形层理、准同生变形构造等,主要发育鲍玛序列A段和AB段组合,缺失CDE段。对该重力流沉积体的初步研究表明,其具有大规模、多期次（浊积事件的垂向叠加序列组合）、持续性发育等特征。在浅海背景下形成大规模重力流沉积体的综合成因机制包括：（1）物源的持续供给;（2）同沉积期大规模海退作用;（3）陆架基底的幕式动态活动和差异性沉降。该重力流沉积体的发育受上述三大因素的联合控制。因此,本研究采取构造-层序地层学、沉积学与地球物理相结合的系列技术与方法研究其宏观、微观特征及堆积的控制要素与独特机制。该研究成果能丰富浅海区发育大型重力流沉积体的理论体系,对油气勘探新领域的拓展具重要的借鉴价值。
Large efficient reservoir-shallow marine gravity flow deposits of the Huangliu Formation in Yinggehai Basin,south China,which are located at the central Dongfang area,represent the peculiarity in sedimentary features and deposit mechanism.The paleontology study of these gravity flow deposits indicates that the paleo-water depth was 40-110 m,which implies a shallow shelf environment.The gravity flow features include convolute deformation bedding and contemporaneous deformation structures.The vertical series are mainly Bouma sequence A and AB,which are lack Bouma CDE.The gravity flow deposits show the features of large scale,multiple phases（superposition of turbidite events and combination of vertical series）,and sustainable development.The comprehensive genetic mechanism of the large gravity flow deposits that formed in shallow marine environments includes the following features：（1）continuously sources supply,（2）large-scale regression during the syndepositional period and（3）episodic dynamic and differential subsidence of shelf paleo-geomorphology.The gravity flow deposits on the shallow marine shelf are the combined controlling results of source supply,tectonic activity,and relative sea level change,which represent high coordinated relationship between these influence factors.Therefore,this study will focus on the microscopic and macroscopic features,accumulation controlling factors,and particular mechanism of the shallow marine gravity flow deposits based on the research method and technique of tectonic-sequence stratigraphy,sedimentology,and geophysics exploration.Intensive study of these shallow marine gravity flow deposits provides important theoretical value and practical significance for the theoretical research of large gravity flow deposits in the shallow marine environment,and also provides reference for the frontier exploration of oil and gas.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2015年第1期21-34,共14页
Earth Science Frontiers
基金
国家自然科学基金项目(41472084)
国家油气重大专项子课题(2011ZX05009-002)
关键词
莺歌海盆地
黄流组
浅海相
重力流沉积体(浊积扇)
堆积机制
Yinggehai Basin
Huangliu Formation
shallow marine facies
gravity flow deposits（turbidites deposits）
accumulation mechanism
