摘要
莲花山断裂带是一条多期变形变质带。研究表明,该变质带既有某些区域变质作用的特征,又有明显不同之处。变质带明显受断裂带控制,切割地层界线,线型雁列,发育于地热异常高值区和应力集中带,温度梯度陡,变化快,变质相带侠窄。它不论在时空展市上,还是在形成机制上,都与断裂构造带密切相关,据此认为该期变质作用是在动力和热力都比较活跃的环境中形成,是温度、压力和构造应力综合作用的结果。
The fault dynamo-thermal metamorphic belts are limited within the Lianhua-shan fault zone.In the plate,it can be divided into three belts in the form of equidistant echelon. The schistose trend intersects the trend of fault zone and the stratum by 10°-15°. In the cross section, the metamorphic rock belts are quite narrow. A progressing series from phyllite-quartz-dimicaeous schist to garnet-staurolite schist is obsered only within several hundred meters. It shows a very steeply geothermal grade.The metamorphic belts lie in the belts with strong stress and geothermal controlled by the fault zone. Many typical metamorphic minerals and various stress traces which were formed during the metamorphism can be found in the rocks.The metamorphic temperature ranges from 300℃ to 600℃ and the pressure from 0.26 to 0.7 GPa, but the largest thickness of the primary rocks is about 6000 meters in the fault zone.It could not afford enough heat and pressure to satisfy the metamorphism. Evidently, the dynamo-thermal metamorphism differs from the regional metamorphism and results from the multiple effect of the geothermal flow,the tectonic stress and the confining pressure.
关键词
断裂
动热变质带
广东省
fault,dynamo-thermal metamorphic belt,Guangdong Province
