摘要
华中高压变质带中的蓝晶石黄玉岩系指一套富含铝质矿物的岩石,其矿物组合为蓝晶石+钠云母士白云母,蓝晶石+黄玉士石英,蓝晶石+蓝刚玉士硬绿泥石,蓝品石+白云母+石英等.化学成分富铝而贫镁。原岩为一套铝质粘土岩—砂岩.形成的温压条件为P=1.0～2.0GPa,T=650～900℃.其成分与典型的白片岩有所不同。故称为“类白片岩”.白片岩类是地壳物质俯冲到地幔深度的指示剂,从而证明华中高压变质带是古陆内板块裂开、碰撞、俯冲的产物。
The high-pressure metamorphic belt in centralChina consists of blueschist, eclogite and kyanite-topaz rocks. The Kyanite-topaz rock is a kind of rocks which containAl-rich minerals. It occurs mainly in middle proterozoic its country rocks are various schists. Typical mineral associations are Ky+Tz+Q, Ky+Co, Ky+Pa + Ms, Ky+Ms+Q. The chemical compositions are Al-rich and Mg-poor. The original rocks are Al-richclay rocks and sandstones. The conditionofmetamorphism is P=1. 0-2. OGPa, T=650 -900℃. The mineral associations are different from typical whiteschist (Ky+Tc) , but their geological significance is similar. They are all metamorphic pelite under the high-presure metamorphic condition and regarded as a indicator of crustal materials subducted to the mantle depths. Thus, the Kyanite-topaz rock in central China is named quasi-whiteschist. Itis proved that the high-pressure metamorphic belt in central China is a product of splitting , collision and subductionbetween continental plates.
关键词
蓝晶石
黄玉岩
白片岩
变质带
kyanite-topaz rock, quesi-whiteschist, high - pressure metamorphic belt, continental collision, Central China
