| 贺昕宇,方同辉,刘海鹏,张宝琛,李艳艳,王京,张浩钰.东天山星星峡地区星星峡岩群的划分、地球化学特征与地质意义[J].矿产勘查,2021,12(7):1519-1529 |
| 东天山星星峡地区星星峡岩群的划分、地球化学特征与地质意义 |
| Classi.cation, geochemical characteristics and geological signi.cance of the Xingxingxia Complex in Xingxingxia Area, Eastern Tianshan |
| 投稿时间：2020-06-02 |
| DOI： |
| 中文关键词: 东天山 星星峡岩群 变质岩 原岩恢复 构造环境 |
| 英文关键词: Eastern Tianshan Xingxingxia complex metamorphic rock metamorphic protolith recovery tectonic setting |
| 基金项目:本文受东天山成矿带景峡地区地质矿产调查(编号:DD20160011)、我国紧缺矿产资源保障与全球布局战略(编号:DD20190199)资助。 |
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| 中文摘要: |
| 星星峡岩群广泛分布于东天山卡瓦布拉克至星星峡一带，为一套变质程度不均匀的变质岩系。自 1965年首次提出至今已 50余年，虽历经多次厘定，但因其内部成分较为复杂，需进一步解体、划分，对其原岩性质以及形成的构造环境也有不同的认识。星星峡地区星星峡岩群变粒岩、片岩、千枚岩具有明显的 Nb、 Ta负异常， Cr/Zr小于 1，轻、重稀土分馏较强。正斜长角闪岩稀土配分模式曲线右倾不明显( LaN/YbN=0.80~2.84， LREE/HREE=1.45~3.61)，而副斜长角闪岩呈明显右倾( LaN/YbN=5.89， LREE/ HREE=6.10)，重稀土含量相对较低。星星峡岩群原岩为一套沉积 -火山岩建造，变质程度为绿片岩相 -角闪岩相，沉积岩源区物质主要为长英质岩石，有少量镁铁质贡献，火山岩多为酸性火山碎屑岩和基性火山岩。星星峡地区星星峡岩群可划分为 3个岩组，解体出原属星星峡岩群的变质花岗岩和中性火山岩，分别划归新元古代花岗岩和泥盆纪花岗岩。星星峡岩群形成于活动大陆边缘，火山岩属陆缘弧岩浆岩，晚期沉积岩可能形成于较为低能的弧间盆地。 |
| 英文摘要: |
| The Xingxingxia Complex was a suite of metamorphic series with heterogeneously metamorphic grade, and widely distributed from Kawabulake to Xingxingxia Area, Eastern Tianshan. Since being .rst proposed in 1965, the Xingxingxia Complex has been determined several times during the past 50 years. However, considering the complicated composition of this complex, it should be further disintegrated and divided. Meanwhile, there are still different views of its protolith and tectonic environment. The granulite, schist and phyllite of the Xingxingxia Complex were characterized by obviously negative anomalies of Nd and Ta, low Cr/ Zr value (<1) and strong fractionation between light and heavy REE elements. The REE distribution pattern of ortho-amphibolite manifested as .attened or slightly right-inclined curves, while that of para-amphibolite showed obvious right-inclined curves with less content of HREE. The protholith of the Xingxingxia Complex was a set of sedimentary-volcanic formation, which experienced metamorphism varying from low-grade greenschist facies to amphibolite facies. Provenance of sedimentary rocks were mainly felsic rocks with minor ma.c components, and volcanics were mostly composed of felsic pyroclastic rocks and ma.c extrusive rocks. The Xingxingxia Complex could be subdivided into 3 formations, from which metamorphosed granites and intermediate volcanics were disintegrated and incorporated into Neoproterozoic and Devonian granite, respectively. This Complex formed in active continental margin and volcanic rocks belonged to arc-related magmatite, while the late-stage carbonate formation might be deposited in inter-arc basin, representing low energy environment. |
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