本文選題：新疆北山 + 高級變質(zhì)巖系��； 參考：《巖石學(xué)報》2016年06期

【摘要】：新疆北山鹽灘斷裂南一帶從原劃奧陶-志留系地層中解體出古老的角閃巖相-麻粒巖相變質(zhì)巖和變質(zhì)侵入巖體,主要巖性為黑云母斜長片麻巖、條帶狀混合巖、斜長角閃巖、及少量變粒巖、麻粒巖等。其中首次發(fā)現(xiàn)了代表中、下地殼深變質(zhì)作用的中-高壓基性麻粒巖。詳細的野外調(diào)查、巖相學(xué)及礦物學(xué)研究表明,該基性麻粒巖主要由透輝石、紫蘇輝石、褐色普通角閃石及拉長石組成。其演化經(jīng)歷了由麻粒巖相巖石經(jīng)退變質(zhì)反應(yīng)而成為角閃巖相變質(zhì)巖的過程。研究表明,該區(qū)麻粒巖中的單斜輝石及角閃石礦物學(xué)成因均屬于變質(zhì)成因,其中單斜輝石形成環(huán)境為高壓型,而角閃石形成環(huán)境為中低壓環(huán)境。麻粒巖相變質(zhì)巖形成于約1.25GPa(42km埋深)以下的中高壓-高壓環(huán)境,其形成溫度約841℃;而退變質(zhì)作用下的角閃巖相變質(zhì)巖應(yīng)形成于650~657℃的溫度范圍之內(nèi),壓力為0.460~0.495GPa之間,相應(yīng)的代表埋深約為16.5km的中低壓型環(huán)境。該區(qū)高級變質(zhì)巖及其基性麻粒巖的發(fā)現(xiàn),將對該區(qū)地殼成分、麻粒巖的成因與變質(zhì)作用以及所處的大地構(gòu)造背景演化等研究無疑將起到非常重要的作用。
[Abstract]:The ancient amphibolite-granulite facies metamorphic rock and metamorphic intrusive rock bodies have been disintegrated from the Ordovician strata in the southern area of Beishan Yantan fault in Xinjiang. The main lithology is biotite plagiocline gneiss, banded migmatite, and amphibolite. And a small amount of granulite, etc. The intermediate-high pressure basic granulites representing the deep metamorphism of the middle and lower crust were first found. Detailed field investigation, petrographic and mineralogical studies show that the basic granulite is mainly composed of diopside, perilla pyroxene, brown common hornblende and elongate. The evolution of amphibolite metamorphic rocks from granulite facies rocks to amphibolite facies metamorphic rocks by retrograde metamorphism. The results show that both clinopyroxene and hornblende mineralogy in granulite belong to metamorphic origin. The formation environment of clinopyroxene is high pressure and that of hornblende is middle and low pressure. The granulite facies metamorphic rocks were formed in the medium and high pressure environment (about 1.25GPa(42km buried depth) and the formation temperature was about 841 鈩，

本文編號：1933913