摘要
在大石桥地区进行1:50000地质填图过程中,经过大量的岩石薄片观察,在江河岩群变泥质岩石中,首次发现了红柱石转变为蓝晶石和十字石转变为蓝青石的变质反应.详细的岩相学、岩石化学及矿物化学的研究表明,变泥质岩中先后发生的这两种变质反应,代表了本区变质作用演化的两个重要阶段.揭示了本区在伸展体制下地壳拉伸、减薄和收缩体制下的褶叠、推覆及之后的抗返、抬升的地球动力学过程.
During 1:50000 geological mapping in Dashiqiao area,it was found that andalusite changed into kyanite and staurolite changed into cordierite,throungh the observations of slice.The studies on petrography, petrochemistry and mineral chemistry show that above two metamorphic reactions in the metamorphic politic rocks pointed out two important stases in the metamorphic evolution and indicatedthe process of the Earth dynamics from extension to compression and then lift.