河南桐柏地区麻粒岩和片麻岩的岩石学特征及其成因意义

对河南桐柏地区麻粒岩及其周围以前被认为是片麻岩的岩石从野外特征、结构构造、矿物成分、化学成分及峰期变质条件上进行比较，认为它们均相同。似层状、透镜状麻粒岩间以前被认为是高度风化片麻岩的岩石仍是麻粒岩，这是后期应力作用产生差异变形、退变质及风化作用的结果。这种变化不能等同于麻粒岩退变质为片麻岩。因此，桐柏麻粒岩的北侧围岩是与其呈断层接触的大理岩，南侧围岩为郭庄组上段花岗质片麻岩，麻粒岩构成一个约0．5km～2．0km宽的变质带。这对探讨桐柏麻粒岩的形成和演化具有重要意义。

THE PETROGRAPHIC CHARACTERISTICS AND PETROGENIC SIGNIFICANCE OF THE GRANULITES AND GNEISSES IN TONGBAI AREA,HENAN PROVINCE

The features of the granulites have been analyzed in detail in Tongbai area, Henan province. By studying in the field features, textures, structures, mineral composition and metantorphic conditions,the rocks usually regarded as the high weathered gneiss are the same type granulite. Their different occurrences may be from the different later stage deformation, the differently retrogressive metamorphism and weather. These changes isn't equivalent with the granulite retrogressively metamorphose to the gneiss. The northern adjoining rocks of granulites are marbles which adjoin to granulites by faults, and south adjoining rocks are granite geneiss of upper Guozhuang formations. Granulites form a belt 0.5 km~2.0 km wide in Tongbai area. For making a thorough inquiry about the formation and evolution of the granulites, It is more significant to understand the occurrence of the granulite in Tongbai area.