郯庐断裂带莱州湾段新生代活动演变及其沉积-改造效应

发布时间：2018-04-16 13:19

本文选题：郯庐断裂带 + 莱州湾地区　；参考：《岩石学报》2016年04期

【摘要】：本文根据对覆盖区地震、钻井等资料的精细解释和深入剖析,揭示在渤海莱州湾地区郯庐断裂带由东、西两条分支断裂带构成,二者又分别由两条主断层及多条次生断层和其间的断块组成。分支断裂带的两条主断层的间距因地而异,一般在5km左右;其结构构造和空间展布特征有别,西支表现为"两断夹一凸"的不对称地垒式,东支主要呈"花状"构造结构。通过古地质构造恢复和分期动态构造演化分析等综合研究,厘定了在新生代不同时期两条分支断裂带在该区不同单元的活动特点和构造-改造效应,进而总结了郯庐断裂带新生代主要阶段的构造属性及其演变。认为在古近纪早中期,研究区处于区域伸展沉降环境,郯庐断裂带对该区的沉积展布无明显控制作用;断裂带活动的明显控制沉积效应始于古近纪晚期,总体具伸展兼右行走滑属性,主要表现为切割和改造了研究区原近东西向展布的优势构造-沉积格局,同时控制了前期沉积地层的剥蚀强度及其分布范围和同期沉积。新近纪以来,郯庐断裂带两条分支断裂带的活动表现出差异显著的东强西弱;于第四纪,在东支断裂带出现正花状反转构造,可能与幕式走滑兼挤压活动有关。
[Abstract]:Based on the detailed interpretation and in-depth analysis of seismic and drilling data in the overlying area, this paper reveals that the Tanlu fault zone in the Laizhou Bay area of Bohai Sea is composed of two branch fault zones in the east and west.The two faults are composed of two main faults and several secondary faults respectively.The distance between the two main faults in the branched fault zone varies from ground to place, generally around 5km, and its structural structure and spatial distribution are different. The western branch is characterized by an asymmetric barrier type of "two faults and one convex", and the eastern branch is mainly a "flower-like" structure.Based on the comprehensive study of the restoration of paleo-geological structures and the analysis of tectonic evolution by stages, the active characteristics and tectonic-reconstruction effects of two branched fault zones in this area in different periods of Cenozoic are determined.The tectonic properties and evolution of the main Cenozoic stages of the Tan-Lu fault zone are summarized.It is considered that in the early and middle Paleogene, the study area is in a regional extensional subsidence environment, and the Tanlu fault zone has no obvious controlling effect on the sedimentary distribution of the area, and the obvious controlled sedimentary effect of the fault zone activity began in the late Paleogene.It is characterized by extensional and right strike-slip properties, which are mainly characterized by cutting and reconstructing the dominant tectonic-sedimentary pattern of the former east-west distribution in the study area, and controlling the denudation intensity, distribution range and synchronic deposition of the Prophase sedimentary strata at the same time.Since the Neogene, the activity of the two branch fault zones in the Tanlu fault zone has shown significant difference between the east and the west, and in the Quaternary, there was a positive flower-like reverse structure in the eastern branch fault zone, which may be related to the episodic strike-slip and compressional activity.
【作者单位】：大陆动力学国家重点实验室西北大学地质学系;
【基金】：国家自然科学基金项目(91214301、90814005)资助
【分类号】：P542

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