本文選題：高級變質(zhì)作用 + 部分熔融��； 參考：《巖石學(xué)報》2017年08期

【摘要】：位于造山帶核部的高喜馬拉雅結(jié)晶巖系是由印度大陸俯沖到亞洲大陸之下經(jīng)歷變質(zhì)作用的產(chǎn)物,是研究喜馬拉雅造山帶形成與演化過程的理想載體。本文對造山帶東段錯那地區(qū)高喜馬拉雅結(jié)晶巖系上部構(gòu)造層位的正片麻巖進行了巖石學(xué)、相平衡模擬,鋯石與獨居石U-Pb年代學(xué)研究。研究結(jié)果表明這些巖石的峰期礦物組合為石榴石+斜長石+鉀長石+黑云母+白云母+石英+鈦鐵礦,保留有深熔作用的結(jié)構(gòu)特征。巖石中的石榴石具有生長成分環(huán)帶。相平衡模擬表明,巖石的峰期變質(zhì)條件為710~750℃和9.0~10.5kbar,具有一個順時針型變質(zhì)作用P-T軌跡,其進變質(zhì)過程以升溫、升壓和部分熔融為特征,退變質(zhì)作用為降溫、降壓過程。鋯石與獨居石U-Pb定年表明,這些正片麻巖具有510~490Ma的原巖年齡,和27~11Ma的退變質(zhì)時間。本研究表明高喜馬拉雅結(jié)晶巖系的上部構(gòu)造層位經(jīng)歷了高角閃巖相變質(zhì)作用與部分熔融,為造山帶的構(gòu)造演化提供了重要信息。
[Abstract]:The high Himalayan crystalline rock series located in the core of the orogenic belt is the product of metamorphism from the Indian continent subducting to the Asian continent and is an ideal carrier for studying the formation and evolution of the Himalayan orogenic belt. In this paper, the petrology, phase equilibrium simulation, zircon and monazite U-Pb chronology of the normal gneiss in the upper tectonics of the upper Himalayan crystalline series in the Dana area of the eastern part of the orogenic belt have been carried out. The results show that the peak mineral assemblage of these rocks is garnet plagioclase potassium feldspar biotite Muscovite quartz ilmenite retaining the structural characteristics of deep penetration. The garnet in the rock has a growth composition ring. The phase equilibrium simulation shows that the peak metamorphic conditions of the rocks are 710 ~ 750 鈩，

本文編號：2039362