川西龙门山前陆盆地晚新生代沉积记录与构造响应

发布时间：2018-01-07 04:05

本文关键词：川西龙门山前陆盆地晚新生代沉积记录与构造响应　出处：《地质学刊》2016年04期 　论文类型：期刊论文

【摘要】：龙门山前陆盆地位于青藏高原东缘,夹于龙门山推覆造山带与龙泉山褶断带之间。自4.6 Ma以来,逆冲推覆构造运动使龙门山造山带强烈隆升,古河流的侵蚀、搬运和堆积作用使盆地沉积了1套巨厚的半固结—松散堆积物。通过对沉积特征和沉积结构的综合研究,认为龙门山前陆盆地是由自东向西的深部多级俯冲潜滑而引起的浅部由西向东的多层次推覆作用形成的,其晚新生代逆冲推覆构造所产生的构造负载是龙门山前陆盆地的成盆动力。岩浆物质的循环过程表明成都盆地在形成过程中遵循物质循环与能量守恒定律。龙门山前陆盆地地质构造的沉积响应表现为:沉积基底整体上向西倾斜,盆地剖面明显不对称;沉积地层与下伏地层均为不整合接触;盆内发育了一系列相间排列的次级凹陷和凸起,并呈雁斜式展布;砾质粗碎屑楔状体的周期性发育。从盆地动力学的角度初步分析了龙门山前陆盆地盆-山耦合关系,龙门山冲断带及其前陆盆地的研究对于大地构造位置、成矿作用以及油气聚集地的勘探等具有重要意义。
[Abstract]:The Longmen Mountain Foreland basin is located in the eastern margin of the Qinghai-Tibet Plateau, between the Longmen Mountain nappe orogenic belt and the Longquanshan fold fault belt. Since 4.6 Ma, the thrust nappe tectonic movement has made the Longmen Mountain orogenic belt uplift strongly. The erosion, transport and accumulation of ancient rivers have resulted in the deposition of a set of massive semi-consolidated and loose deposits in the basin. It is considered that the Longmenshan Foreland basin was formed by the multi-level nappe from east to west caused by the multi-level subduction and subduction from east to west. The tectonic load produced by the late Cenozoic thrust nappe structure is the basin forming power of Longmen Foreland basin. The circulation of magmatic material shows that the Chengdu basin follows the law of material circulation and energy conservation during its formation. The sedimentary response of geological structure in Foreland basin is as follows:. The sedimentary basement is inclined to the west as a whole. The basin profile is obviously asymmetrical; Both sedimentary strata and underlying strata are unconformities; A series of secondary depressions and bulges arranged in interphase are developed in the basin and distributed in a geese's oblique pattern. The periodic development of gravelly coarse clastic wedge-like bodies. The basin-mountain coupling relationship of Longmen Mountain Foreland basin and the study of Longmenshan thrust belt and its Foreland basin are preliminarily analyzed from the point of view of basin dynamics. Mineralization and exploration of oil and gas accumulation areas are of great significance.
【作者单位】：曲阜师范大学;
【基金】：国家自然科学基金项目“龙门山地区涪江上游晚新生代水系演化与新构造响应研究”(41072164)
【分类号】：P618.13;P534.6
【正文快照】： 0引言前陆盆地概念由Price(1973)首次提出,其后许多学者(刘和甫,2001;Dickinson,1993)提出了对前陆盆地的认识。De Celles等(1996)认为前陆盆地系统是在收缩造山带与毗邻的克拉通之间的大陆地壳之上沉积物堆积的潜在地区,沉降主要是与俯冲作用及其导致的周缘或弧后褶皱逆冲带

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