本文選題：大喜馬拉雅結(jié)晶雜巖　切入點(diǎn)：高角閃巖相　出處：《巖石學(xué)報(bào)》2017年08期

【摘要】：大喜馬拉雅結(jié)晶雜巖位于喜馬拉雅造山帶的核部,其變質(zhì)作用的研究是揭示碰撞造山作用和動力學(xué)的關(guān)鍵。本文對喜馬拉雅造山帶中部吉隆地區(qū)的大喜馬拉雅結(jié)晶雜巖中的片麻巖和片巖進(jìn)行了巖石學(xué)和鋯石U-Pb年代學(xué)的研究,表明這些高級變質(zhì)巖經(jīng)歷了高角閃巖相的變質(zhì)作用和部分熔融,以及近等溫降壓的退變質(zhì)過程。片麻巖和片巖的峰期變質(zhì)礦物組合為斜長石+鉀長石+黑云母+白云母+石英±石榴子石±鈦鐵礦和石榴子石+藍(lán)晶石+斜長石+黑云母+白云母+鈦鐵礦+石英,晚期退變質(zhì)礦物組合為斜長石+鉀長石+黑云母+白云母+夕線石+石英±石榴子石和石榴子石+夕線石+斜長石+黑云母+白云母+鈦鐵礦+石英。相平衡模擬研究表明,巖石的峰期變質(zhì)條件為685~755℃和9.5~12kbar,退變質(zhì)作用條件為675~685℃和6~7.4kbar。鋯石U-Pb年代學(xué)表明,高級變質(zhì)巖的部分熔融時(shí)間為38~16Ma,熔體結(jié)晶時(shí)間為17~15Ma。本次研究表明,大喜馬拉雅結(jié)晶雜巖中、上部并沒有普遍經(jīng)歷高壓麻粒巖相變質(zhì)作用,部分地區(qū)包括吉隆地區(qū)經(jīng)歷的是高角閃巖相變質(zhì)作用。此外,本文在吉隆地區(qū)高級變質(zhì)的大喜馬拉雅結(jié)晶雜巖中識別出較低級變質(zhì)的特提斯喜馬拉雅巖系單元。結(jié)合已發(fā)表的藏南拆離斷裂的主要活動時(shí)間,本文認(rèn)為構(gòu)造楔模型更適用于研究區(qū)喜馬拉雅造山過程的解釋。
[Abstract]:The great Himalayan crystalline complex is located at the core of the Himalayan orogenic belt. The study of metamorphism is the key to reveal the collision orogeny and dynamics. In this paper, the petrology and zircon U-Pb chronology of the gneiss and gneiss in the greater Himalayan crystalline complex in the Jilong area of the central Himalayan orogenic belt have been studied. These high grade metamorphic rocks experienced metamorphism and partial melting of high amphibolite facies. The peak metamorphic mineral assemblage of gneiss and schist is plagioclase potassium feldspar Muscovite quartz 鹵pomegranate 鹵ilmenite and garnet blue crystal plagioclase. Biotite Muscovite ilmenite quartz, The late retrograde metamorphic mineral assemblage is plagioclase potassium feldspar biotite Muscovite quartz 鹵pomegranate and pomegranate silvicite plagioclase biotite Muscovite ilmenite quartz. The peak metamorphic conditions of the rocks are 685 ~ 755 鈩，

本文編號：1679353