摘要
对耒阳—临武经向构造带内的白沙含煤向斜用计算机计算镜质组反射率椭球确定了古构造应力场方向,发现其与煤变质分带没有联系。笔者还将研究区中的其他几个向斜内煤的变质程度与构造形迹、构造复杂程度、煤受构造破坏程度进行了对比研究。研究结果表明,煤变质指标等值线延展方向与向斜轴不平行而呈大角度相交;受挤压强烈的向斜陡翼的煤变质程度并不高于受挤压相对弱的缓倾斜翼;祁阳山字型构造中煤变质指标等值线延展方向穿切前弧而不按受挤压强烈程度变化;受挤压强烈的构造煤的变质程度并不高于受挤压相对弱的非构造煤甚至低于后者。湘中南煤变质程度的高低与地质构造无直接关系。构造变形强烈的含煤隆褶带、含煤盆地或其中变形相对强烈的某个构造部位中煤的变质程度并不一定高,而其中的煤级升高应有非构造应力形成的热源机制。
In this paper, the direction of the palaeostructural stress field of the Baisha syncline is determined by computing the reflectance ellipsoid of vitrinite in the coal samples, and it is found that it has no relations with the metamorphic zoning of coal. The author also presents a comparison of the grade of coal metamorphism with the structural features, the complicacy of structures, and the degree of coal deformation in several structures in the syncline. The research shows that the extension of isolines of coal metamorphism or coal rank intersects the syncline axis trace at a high angle; the metamorphism grade of coal strongly compressed is no higher than that weakly compressed ; the R0,max% isolines of vitrinite intersect the Qiyang epsilon-type structure arc; the metamorphism of tectonically strongly deformed coal (such as the mylonitic coal) is no higher than the non-deformed coal. Therefore, the grade of coal metamorphism in central-south Hunan is not directly related to the geologic structures.
出处
《地质论评》
CAS
CSCD
北大核心
2000年第1期64-70,共7页
Geological Review
关键词
湘中南地区
煤变质
地质构造
煤矿床
grade of coal metamorphism
reflectance ellipsoid
tectonic structrure
