摘要
安徽省淮北煤田推覆构造外来系统与原地系统中的煤镜质组反射率各向异性特征存在明显差异,反映不同的应力应变状态。外来系统中最小反射率的倾向由北北西转至北西西,代表推覆体前锋带的应力状态;反射率光率体以长球形椭球体为主,意味着推覆过程中伴随有侧向伸长变形。原地系统中最小反射率的倾向为南南西和南南东,保存了区域性南北向挤压的痕迹;反射率椭球体有限应变分析结果为压扁型应变。本文的实例表明,煤镜质组反射率各向异性分析技术是研究煤田推覆构造的一种可行手段。
There is a great difference in the vitrinite reflectance anisotropy between the allochthon and autochthon of the nappe structure in the Huaibei Coalfield, Anhui province, which reflects different states of stresses and strains. The dip of the minimum reflectance (R_c) in the allochthon turns from NNW to WNW, indicating the state of stresses in the frontal zone of nappe. Most of the reflectance indicatrix are prolate ellipsoid, implying a lateral extensional strain during thrusting. The dips of the minimum reflectance (R_e) in the autochthon are SSE and SSW, preserving the sign of a regional N-S compression. The finite-strain analysis of the reflectance ellipsoid shows a flattened strain. The example given by the paper shows that the technique of analysis of vitrinite reflectance anisotropy is an effective means for the study of nappe structure in coalfields.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第4期333-340,共8页
Geological Review
