内蒙古布林庙晚石炭世碱长花岗岩的发现及其对古亚洲洋演化的制约  

Discovery of the Late Carboniferous alkali-feldspar granite from the Bulinmiao area in Inner Mongolia and its constraints on the evolution of the Paleo-Asian-Ocean

作　　者：郝书清 戎秀伟 王丽娟[2] 李猛兴 HAO Shuqing;RONG Xiuwei;WANG Lijuan;LI Mengxing(Shanxi Third Geological Engineering Investigation Institute Co.,Ltd.,Jinzhong 030620,Shanxi,China;Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,Hebei,China;Shanxi Institute of Geological Survey Co.,Ltd.,Taiyuan 030006,Shanxi,China)

机构地区：[1]山西省第三地质工程勘察院有限公司,山西晋中030620 [2]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [3]山西省地质调查院有限公司,山西太原030006

出　　处：《地质通报》2022年第9期1613-1623,共11页Geological Bulletin of China

基　　金：中国地质调查局项目《1:5万哈达图(L50E013019)等四幅区调》(编号:12120113056400);自然资源部项目《我国典型地区大气水-地表水-地下水资源综合评估与水平衡研究——以滹滏平原为例》(编号:B201905)。

摘　　要：对贺根山蛇绿岩带北缘的布林庙碱长花岗岩体进行了LA-ICP-MS锆石U-Pb定年、岩石地球化学特征研究,以期解释其岩石成因及地质意义。研究表明:碱长花岗岩体的锆石U-Pb年龄为304±1 Ma,为晚石炭世岩浆活动的产物;所有样品的地球化学特征相似,表现为高硅、富碱且相对富钾、弱过铝质的特点,富集Rb、K等大离子亲石元素,贫P、Sr、Ti等元素。结合样品的10000Ga/Al值、TFeO含量、Zr含量、锆石饱和温度等相关指标,认为岩体为高钾钙碱性(钾玄岩)系列的A型花岗岩。岩体形成于贺根山洋盆闭合后,是古亚洲洋造山后伸展阶段早期阶段的产物。In this paper,LA-ICP-MS zircon U-Pb dating and geochemical characteristics of the Bulinmiao alkali-feldspar granite pluton located in the northern margin of the Hegenshan ophiolite belt are studied in order to explain its petrogenesis and tectonic significance.The study shows that the zircon U-Pb dating give weighted average age of 304±1 Ma,indicating that it is the product of magmatic activity in the Late Carboniferous.The general characteristics of the granite samples are similar,showing the characteristics of high silicon,rich alkali,rich K,and weak peraluminous.Trace elemental data of these rocks show LILE(Rb,K)enrichment,HFSE(P,Sr,Ti)depletion.Combining with the 10000Ga/Al value,TFeO,Zr contents and zircon saturation temperatures of the sample,the pluton is an aluminous A-type granite and belongs to the high-K calc-alkaline series.The granite was the product of the early stage post-orogenic extension after closure of Hegenshan Ocean.

关 键 词：布林庙 碱长花岗岩 锆石U-PB年龄 地球化学 岩石成因 地质调查工程 内蒙古 

分 类 号：P534.45[天文地球—古生物学与地层学] P588.121[天文地球—地质学]