下扬子区苏北—南黄海中生界、古生界构造格架对比分析

发布时间：2018-12-17 19:39

【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。
[Abstract]:Based on the correlation and analysis of regional seismic profiles in recent years, the unity and difference of Paleozoic hedges of Huang Hai in northern and southern Jiangsu are discussed. The unity is characterized by stratigraphic opposability, reflection of the same (similar) basement and caprock, hedge zone and thrust fold, all of which reflect the progressive deformation characteristics of the NW--SE plate. The difference is that north of the hedge belt, the overland is dominated by shallow metamorphic rocks and the top, the Doushantuo formation is supplemented by a strong slipping-nappe back, and the syncline fold alternates. Then the upwelling (A zone) -thrusting (B zone) -C (C zone) imbricate thrust occurred in the front edge of the anticline. The deep and shallow metamorphic rocks formed two sets of high angle thrust folds in the background of wide and slow anticline. It is considered that the shearing and detachment strata (sea area) and the slip pushing layer (land) are the important factors that cause the difference of the structure between the land and the sea area. The calculation of the extensional amount shows that the Paleozoic has undergone three stages of deformation since the late Indosinian, the early Indosinian, the middle hedging, the nappe and the strike-slip, the late Yanshanian extension and the fault-depression stage since the late Cretaceous. So far, although Huang Hai in the north and south of Jiangsu has compressed, the shape of "bell-mouth" has remained basically unchanged, mainly due to the different deformation modes of land- sea area.
【作者单位】：成都理工大学能源学院;油气资源与勘探技术教育部重点实验室;长江大学地球物理与石油资源学院;中国石油化工股份有限公司勘探分公司;中海石油(
【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~~
【分类号】：P548

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