云蒙山地区晚中生代花岗岩成因分析及地质意义  

Genesis and Geological Significance of Late Mesozoic Granites in Yunmengshan Area

作　　者：王磊 李建波[1] 史峻丞 梁键婷 曾涛[1] WANG Lei;LI Jian-bo;SHI Jun-cheng;LIANG Jian-ting;ZENG Tao(East China University of Technology,Nanchang 330013,China;Foshan Branch of Ganzhou Engineering Investigation Institute of Nuclear Industry,Foshan 528000,China)

机构地区：[1]东华理工大学,江西南昌330013 [2]核工业赣州工程勘察院佛山分院,广东佛山528000

出　　处：《东华理工大学学报（自然科学版）》2022年第6期538-547,共10页Journal of East China University of Technology(Natural Science)

基　　金：国家自然科学基金项目(41662014)。

摘　　要：为了研究云蒙山地区花岗岩体成因及源区问题,对该区主要出露的云蒙山岩体、长圆杂岩体、西白莲峪岩体和柏岔岩体开展岩相学、岩石地球化学及Sr-Nd同位素分析。结果表明:4个岩体具富硅和富碱特点,属于高钾钙碱性系列;A/CNK值为0.84~1.07,属准铝质-弱过铝质I型花岗岩;各岩体富集大离子亲石元素和轻稀土元素,亏损高场强元素,无或弱的负Eu异常;具有高Sr,低Y和Yb, Sr/Y和(La/Yb)_(N)值高等特征,属于埃达克岩,其原岩来自壳幔混合源区,为古老下地壳部分熔融的产物。本区花岗岩的形成是由晚侏罗-早白垩世蒙古-鄂霍次克洋的闭合和古太平洋板块对欧亚大陆俯冲所致。In order to study the genesis and source zone of granite bodies in Yunmengshan area, petrography, petrochemistry and Sr-Nd isotope analysis were carried out for Yunmengshan pluton, Changyuan complex, Xibailianyu pluton and Baicha pluton exposed mainly in the study area.The results indicate that the four rocks are rich in silicon and alkali, belonging to high potassium calc-alkaline series. The A/CNK value is 0.84~1.07,belonging to quasi-aluminous and weak peraluminous I-type granite. Each pluton is rich in large ion lithophile elements and light rare earth elements, depleted in high field strength elements, and has no or weak negative Eu anomaly;it is characterized by high Sr, low Y and Yb, high Sr/Y and(La/Yb)_(N)values, and belongs to adakite. Their protolith were derived from the crust-mantle mixing source area, and were the product of partial melting of ancient lower crust. The formation of granites in this area resulted from the closure of the Mongolia-Okhotsk Ocean in the late Jurassic-early Cretaceous and the subduction of the ancient Pacific plate forward Eurasian continental block.

关 键 词：SR-ND同位素 变质核杂岩 花岗岩 云蒙山 

分 类 号：P581[天文地球—岩石学]