沉降曲线在造山带盆地研究中的应用——以南秦岭晚加里东期前陆盆地为例  

The application of tectonic subsidence curves in the study of orogenic basins

作　　者：胡云绪[1] 曹宣铎[1] 

机构地区：[1]中国地质调查局西安地质矿产研究所,陕西西安710054

出　　处：《地质通报》2002年第8期501-504,共4页Geological Bulletin of China

基　　金：国家自然科学基金(49572112);国土资源部国际合作与科技司"九五"地学前缘项目(9501126)资助。

摘　　要：造山带中较古老的沉积盆地现今已隆升成山,盆地原型不复存在,但根据沉降曲线反演中的“沉积物的压实过程是不可逆的”这一假设,仍可对其进行沉降曲线分析。南秦岭晚加里东期前陆盆地的原型研究程度高,运用沉降曲线分析常用的数学模型对其进行计算,获得了理想的沉降曲线。结果表明,该前陆盆地是由陆内裂陷演变而来,进入压陷挠曲阶段后,构造沉降的贡献逐渐变小,盆地基底的快速沉降是由快速堆积的沉积载荷引起的。这与地质解释相吻合。Old sedimentary basins in orogenic belts now have been uplifted into mountains and the proto-types of these basins no longer exist.According to the hypothesis that the process of compaction of sedi-ments is irreversible in the backward deduction of the subsidence curve,however,we can still make an analysis of their subsidence curves.The prototype of the Late Caledonian foreland basin in the South Qin-ling Mountains is intensively studied.It was calculated using the mathematic model that is commonly used in the subsidence curve analysis and an ideal subsidence curve was thus obtained.This curve indicates that the foreland basin evolved from the intracontinental rifting and that after entering the compressive flexural deformation stage the contribution of tectonic subsidence becomes smaller and smaller.It is concluded that the rapid subsidence of the base of the basin was caused by the load of sediments that accumulated rapidly,which coincides with the geological interpretation.

关 键 词：沉降曲线分析 前陆盆地 晚加里东期 秦岭 造山带 数学模型 

分 类 号：P542[天文地球—构造地质学]