摘要:
南黄海盆地位于下扬子地台的东北部、郯庐断裂带以东的活动区内,是一个在前震旦系变质岩基底之上,经海相中—古生界、陆相中生界和新生界多期沉积叠覆而成的叠合盆地。近年来,在崂山隆起上的地震剖面获得了较好的深层反射,隆起上存在较连续分布、厚度超过4~5 km的中生界—上古生界地层。但由于中—古生界海相地层的勘探程度低,制约着该区油气勘探的进程。通过地震资料解释,结合邻区钻井与区域地质资料,研究了崂山隆起区海相中—古生界地层的构造地质特征,结果表明,崂山隆起区以下志留统高家边组泥岩滑脱带为界划分为上下2套海相构造层,其形成演化受晋宁运动、广西运动、东吴运动以及印支运动等影响,经历了基底形成、被动边缘克拉通、稳定台地、抬升剥蚀及陆内造山阶段。其中海相上构造层假整合或不整合覆于海相下构造层之上,由于受后期印支、燕山等构造运动的强烈改造作用,造成其在崂山隆起区遭受强烈的隆升褶皱和剥蚀夷平,逆冲断裂广泛发育,并伴随着逆掩推覆和滑脱作用,上构造层的上部地层显著减薄甚至缺失,残留厚度变化较大。该区断裂发育较弱,主要有2组方向的断裂,一组为EW向断裂,这类断裂规模较大,但不发育;一组为NE向断裂。
Abstract:
The South Yellow Sea Basin is located in the northeast of the lower Yangtze platform and the active region to the east of Tanlu faults zone. It is a multi-cycle superimposed basin consisting of the marine Mesozoic-Paleozoic basin overlaid by the continental Mesozoic-Cenozoic basin on the basis of the Presiniancratonic basement. In recent years, high quality deep reflections have been obtained from the seismic profiles passing through the Laoshan Uplift. It is found that the continuous Mesozoic and Paleozoic is more than 4~5 km in thickness. Because of the insufficient exploration for marine Mesozoic-Paleozoic, the oil and gas exploration in the area is restricted. Based on the seismic data, combined with drilling data from its adjacent areas as well as regional geological data, we studied the Mesozoic-Paleozoic geotectonic characteristics of the Laoshan Uplift. The results show that there are two marine structural layers on the Laoshan Uplift, separated by a mudstone detachment zone of Lower Silurian, i.e. the Gaojiabian Formation. This area experienced the evolutionary stages of the formation of basement, the development of craton, the stable platform, the uplift and erosion, and the continental orogeny. The upper structural layer is relatively complex, where thrust folds and imbricate thrust faults are developed. It lies unconformablyupon the lower structural layer. The fracture development of this area is weak.There are two main groups of fractures. Faults developed along E-W direction are relatively large, and those developed in N-E direction are subordinate.
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