摘要
通过近年区域地震剖面对比解析,在建立起苏北与南黄海中、古生界对冲构造格架的基础上,探讨其统一性和差异性。统一性表现为地层可对比、相同(似)的基底与盖层反射和对冲带及冲断褶皱,均体现了NW——SE板内递进变形特点。差异性表现为对冲带以北,陆上以浅变质岩内幕及顶部为主、陡山沱组为辅上覆强烈滑脱—→推覆的背、向斜褶皱交替,进而在背斜前缘产生仰冲(A带)—→逆冲(B带)—→掩冲(C带)叠瓦冲断;而海域则以更深层深、浅变质岩间破裂—→拆离—→上拱,形成了两组在宽缓背斜背景上的高角度冲断褶皱。认为深浅不同的剪切拆离层系(海域)和滑脱推覆层(陆上)作用,是造成陆上与海域构造差异性的重要因素。伸缩量计算表明中、古生界在经历了印支晚期—→燕山早、中期对冲—→推覆—→走滑、燕山晚期伸展和晚白垩世晚期以来断—→坳阶段三期变形,至今苏北与南黄海虽有压缩但"喇叭口"形态基本不变,主要源于陆上—→海域变形方式不同所致。
Objectives： At present, the understanding of the structural and deformation characteristics of Mesozoic and Paleozoic in North Jiangsu—South Yellow Sea region is relative weak due to the data restriction of seismic, drill and outcrop, which limits the exploration of oil and gas. It is significant to establish and compare the detailed regional tectonic frameworks, and then to explore their uniformity and difference. Methods： This study investigates the uniformity and difference of tectonic deformation and evolution of Meso—Paleozoic in the North Jiangsu—South Yellow Sea region, on account of the comparison and analysis of recent regional seismic profiles. Results： Meso—Paleozoic tectonic frameworks are divided into four units. The basement and its overlying sedimentary strata experienced a process of detachment, slippage, napping and thrusting under strong squeezing. Two strike—slip systems are respectively dominated by NW with less of NNW and NNE, showing a high—angle shear relationship with near EW regional structure. Conclusions： The hedge tectonics are various. The uniformity appears as the comparability of strata, the similarity of basement and cap reflection, and the same characteristics of hedge belts and thrust folds with NW—SE inner—plate progressive deformation. The difference manifests as strong slippage to alternately of napping anticline and syncline, which is dominated acted in the body and the surface of the metamorphic rocks, followed by Doushantuo Formation on the land at the north of the hedge belt, and then it is characterized by imbrication thrust consisting of obduction （A zone）, thrust （B zone） and overthrust （C zone） in the front of anticlines. The sea area is characterized by tectonic formation of deeper deep and shallow metamorphic rock ruptures, detachment and arch thrust, which are formed into two groups of high—angle thrust folds in the wide and gentle anticline. Furthermore, although North Jiangsu—South Yellow Sea area has experienced the hedge—nappe—slip stage from late Indosinian to early and middle Yanshanian, extension stage in the late Yanshanian, and rift—depression stage since late late Cretaceous, its “horn” pattern is basically unchanged, which is mainly caused by the different ways of the tectonic formations on the land and in the sea.
作者
龚晓星
佘晓宇
裴振洪
施泽进
丁小辉
李冬冬
GONG Xiaoxing SHE Xiaoyu PEI Zhenhong SHI Zejin DING Xiaohui LI Dongdong(College of Energy Resources, Chengdu University of Teehnology, Chengdu, 610059 Laboratory of Exploration Technologies for Oil and Gas Resources ,Ministry of Education, Yangtze University, Wuhan, 430100 College of Geophysics and Petroleum Resource, Yangtze University, Wuhan, 430100 Exploration Company, SINOPEC, Chengdu, 610041 CNOOC Ltd-Zhanjiang, Zhanjiang, Guangdong, 524057)
出处
《地质论评》
CAS
CSCD
北大核心
2017年第4期941-954,共14页
Geological Review
基金
中国石化勘探项目“苏北-南黄海中生界、古生界构造演化与勘探目标优选”和“江苏下扬子地区中、古生界油气保存条件评价”的成果~~
关键词
苏北—南黄海
中生界、古生界
构造对比
推覆—对冲—剪切
滑脱层系
伸缩量
North Jiangsu—South Yellow Sea
Meso—Paleozoic
tectonic comparison
Nappe—hedge—shear
Slippage formation
Expansion amount
