摘要
对张家界风景区进行1/25000遥感地质调查,解译出1031条线性构造,经野外验证可靠性达85％,新确认该区存在北北东向褶皱,提出了该区经历了两次以上的褶皱构造运动的新认识。认为北北东和北东东向构造是该区的基本构造骨架,设计了区域性印支期和张家界风景区印支期、燕山早期、燕山晚期四种应力场模型,采用有限单元法进行构造应力场反演计算,所获结果与野外调查结果吻合。认为砂岩峰林地貌是泥盆纪石英砂岩处于宽缓向斜扬起端及后期背斜叠加使地层趋于水平的部位才利于砂岩峰柱的稳定形成,多次构造应力作用产生的高角度裂隙有利于峰林地貌的造型,挽近时期地壳抬升是峰林地貌形成的动力。
In the 1/25000 scale remote sensing geological investigation in Zhangjiajie scenic area, 1031 lineaments were interpreted, which were checked up through field study and whose reliability reaches 85％. It is newly confirmed that there are NNE trending folds in this area, and it is considered that this area has undregone more than two times folding structural movements, the NNE and NEE trending structures are the basic structural framework in this area. Four models were designed to fit the regional Indo-Sinian stress field and the Indo-Sinian, Early Yanshanian and Late Yanshanian stress field in Zhangjiajie scenic area, and the finite element method is adopted to make inverse inference of the structural stress field, the result obtained tallying with that from field investigation. Moreover, the paper holds that the sandstone forest landscape is formed because that the Devonian quartz sandstone is situated in the rising end of an open syncline, and superposed with late anticline, so the strata tend to be horizontal, which is fovorable for the stablization of the sandstone pillar, many tectonic processes caused to form high-angle fissures, favoring the modelling of sandstone forest landscape. The neoid Crustal uprising is the driving power for the formation of the sandstone forest.
出处
《湖南地质》
1990年第4期23-31,共9页
Hunan Geology
关键词
有限单元法
数值模拟
地质调查
Geologic structure
Simulation of principal stress
Genesis of landscape
