准噶尔东缘卡拉麦里花岗岩带岩浆混合作用——来自A2型花岗岩暗色包体的证据  

Magma Mixing in the Karamaili Granite Belt of East Junggar——Evidence from A2-Type Granite and Their MMEs

作　　者：王磊 郭嘉 张博文 孙亚飞 张春芽 Wang Lei;Guo Jia;Zhang Bowen;Sun Yafei;Zhang Chunya(Tacheng Geological Brigade of Xinjiang Uygur Autonomous Region Geological Bureau,Wusu,Xinjiang,833300,China;Chifeng Yuanye Changshun Geological Exploration Co.,Ltd.,Chifeng,Inner Mongolia,0240000,China;School of Geology and Mining Engineering,Xinjiang University,sUrumqi,Xinjiang,830047,China;Laboratory of Continental Dynamics and Mineralization Prediction in Central Asian Orogenic Belt,Xinjiang University,Urumqi,Xinjiang,830047,China)

机构地区：[1]新疆维吾尔自治区地质局塔城地质大队,新疆乌苏833300 [2]赤峰远野昌顺地质勘查有限公司,内蒙古赤峰0240000 [3]新疆大学地质与矿业工程学院,新疆乌鲁木齐830047 [4]新疆大学中亚造山带大陆动力学与成矿预测实验室,新疆乌鲁木齐830047

出　　处：《新疆地质》2025年第1期1-17,共17页Xinjiang Geology

基　　金：新疆地矿局自筹资金项目(XGMB202361);自治区自然科学基金(2021D01C042)联合资助。

摘　　要：卡拉麦里造山带是准噶尔东缘增生造山带最南缘的重要组成部分,其晚石炭世巨量花岗岩带是研究硅质岩浆演化过程的理想实验室。本文详细研究了萨北、黄羊山及苏吉泉岩体花岗岩及暗色包体的岩相学、岩石地球化学及年代学特征。结果显示,花岗岩及萨北暗色包体具相似锆石U-Pb年龄,分别为(315.9±2.4)Ma、(316.1±2.2)Ma、(319.4±2.0)Ma、(313.9±3.5)Ma。花岗岩为高硅、富碱、弱碱性-准铝质的A2型花岗岩系列,强烈负Eu异常,富集Ta,Th,U及Rb,K,Pb,形成于后碰撞伸展环境;萨北暗色包体为准铝质、钙碱性-高钾钙碱性闪长质包体,具典型岩浆结构,具岩浆混合演化趋势,为基性岩浆底侵上升发生混合作用残留的闪长质包体。晚石炭世卡拉麦里地区底侵作用引起的基性岩浆活动强烈,西段岩体受少量基性岩浆活化作用明显,形成卡姆斯特高分异花岗岩,而东段岩体受基性岩浆物质补给作用明显,形成萨北、黄羊山等富含闪长包体的碱性花岗岩。本次研究以期为该地区巨量花岗岩硅质岩浆演化过程的研究提供一定理论依据。The Karamaili Orogenic Belt is an important part of the southernmost margin of the Junggar East Orogenic Belt,and its Late Carboniferous massive granite belt serves as an ideal laboratory for studying the evolution of silicic magma.This paper elaborately studies the petrology,rock geochemistry,and chronology of granite and MMEs in the Sabei,Huangyangshan,and Sujiquan pluton.The results show that the granite and Sabei MMEs have similar zircon U-Pb ages,which are 315.9±2.4Ma,316.1±2.2Ma,319.4±2.0Ma,and 313.9±3.5Ma,respectively.The granite is of high silica,alkali-rich,weakly alkaline to sub-aluminous A2-type granite series,strongly depleted in Eu,enriched in Ta,Th,U,and Rb,K and Pb,formed in a post-collisional extensional environment;the Sabei MMEs are sub-aluminous,calc-alkaline to high-K calc-alkaline gabbroic enclaves,with typical magmatic structures,and exhibit magma mixing and evolution trends,representing residual gabbroic enclaves from basaltic magma underplating and uprising mixing.In summary,the Late Carboniferous pluton in the Karamaili region induced strong basaltic magma activity;the western section pluton were significantly activated by a small amount of basaltic magma,forming highly differentiated granites such as the Kamusite pluton,while the eastern section pluton were significantly supplied with basaltic magma material,forming alkaline granites rich in gabbroic enclaves such as the Sabei and the Huangyangshan pluton.Finally,this study aims to provide a theoretical basis for the study of the evolution of massive granite silicic magmas in this region.

关 键 词：东准噶尔 卡拉麦里花岗岩带 A型花岗岩 暗色包体 岩浆混合作用 

分 类 号：P619.222[天文地球—矿床学] P588.115[天文地球—地质学]