摘要
被称为"侏罗山式"褶皱的隔挡、隔槽式褶皱在我国川东—湘鄂西一带典型发育。关于其形成机制,主要有粘聚力差异、动力学差异和外营力作用三种说法。川东-湘鄂西地区实地调查发现:(1)以齐岳山断裂为界,西带发育隔挡式褶皱,东带发育隔槽式褶皱;(2)东带缺失含多套泥岩的碎屑岩及一套较厚的膏岩层;(3)西带褶皱仅卷入志留纪之后的地层,而东带卷入了早古生代的基底地层,且正、逆断层更为发育。通过分析有限差法数值模拟实验和定点磷灰石裂变径迹测试的结果,认为层间能干性差异度和推挤力大小的不同是两带地形差异的主导因素。
The comb-like and trough-like folds which are known as Jura-type folds develop well in the eastern Sichuan and western Hunan-Hubei region. There are mainly three statements about the forming mechanism.Interlayer cohesion contrasts,dynamic difference and exogenic process can be possible causes. Field survey found that: 1. By theQiYueShan fracture,the west develops comb-like folds,and the east develops trough-like folds. 2. The eastern strata lack a set of clastic rock which includes many sets of mudstone and a thick paste stratum. 3. The western part of the fold belt only involve the strata after the Silurian while the western part involve early Paleozoic basement strata where develops more positive and reverse faults. Based on the results of numerical modeling experiment by using the finite-different code FL AC and the results of apatite fission track test,the differences in interlayer competence contrast and strength of the compressional deformation between the two parts are considered to be key factors to the terrain differences.
出处
《中山大学研究生学刊(自然科学与医学版)》
2013年第2期50-56,共7页
Journal of the Graduates Sun YAT-SEN University(Natural Sciences.Medicine)
关键词
隔挡式褶皱
薄皮构造
隔槽式褶皱
厚皮构造
comb-like fold
thin-skinned fault-fold
trough-like fold
thick-skinned fault-fold