摘要
二郎坪群主体为一套变质火山岩，夹有少量的变泥砂岩和大理岩。普遍发生了绿片岩相一角闪岩相的变质作用。矿物共生组合及矿物世代关系表明存在两期矿物共生组合，早期以阳起石＋斜长石为代表，晚期以蓝绿色角门石＋斜长石为代表。温压测量结果表明，从早期到晚期变质反应的ＰＴ条件由低温低压向较高温高压演化。利用角闪石环带确定的ＰＴ轨迹为逆时针方向。
The Erlangping Group is a metamorphic volcanic series containing silty argillaceous and carbonate rocks,which commonly underwent greenschist -amphibolite facies metamorphism. According to mineral assemblageand generation,two metamorphic mineral assemblages are recognized from Erlangping Group. One is represented by assemblage of Act+pl, the other by the blue-green horblend+plagioclase.Calculated PT conditions show a tendency of increase in PT. A counter-clockwise rotation PTt path is derived by using the zonedamphiboles of the amphibolites,Which suggests that the late metamorphism of Erlangping Group is a processof increasing pressure.
基金
国家自然科学基金
关键词
变质岩
岩石学
变质作用
演化特征
Xixia
Henan
Erlangping group
North qinling rift
PT path
