河南泌阳梁湾岩体的LA-ICP-MS锆石U-Pb年龄、地球化学特征及地质意义  

LA-ICP-MS Zircon U-Pb age, geochemical characteristics and geologicalsignificance of Liangwan rock mass in Biyang County of Henan

作　　者：许栋 种凯琳 李旭 彭亚南 郭跃闪 XU Dong;ZHONG Kailin;Li Xu;PENG Yanan;GUO Yuesan(Henan Third Institute of Geology and Mineral Resources Survey Co.L td,Zhengzhou 450000,Henan,China;Henan Science and Technology Innovation Center of Natural Resources(Application Research of Information Perception Technology),Zhengzhou 450000,Henan,China)

机构地区：[1]河南省第三地质矿产调查院有限公司,河南郑州450000 [2]河南省自然资源科技创新中心(信息感知技术应用研究),河南郑州450000

出　　处：《矿产与地质》2025年第1期140-151,共12页Mineral Resources and Geology

基　　金：中国地质调查局地质调查子项目“河南省桐柏地区金银多金属矿整装勘查区专项填图与技术应用示范”,(编码:12120114035301)资助。

摘　　要：梁湾岩体位于东秦岭—大别成矿省中部,岩性为似斑状二长花岗岩和似斑状含黑云二长花岗岩。锆石LA-ICPMS U-Pb年龄分别为(130±1)Ma(n=24,MSWD=0.45)、(135±2)Ma(n=23,MSWD=5.5),表明梁湾岩体形成时代为早白垩世。梁湾岩体具有较高的SiO_(2)(68.06%~74.78%)、富K贫Na、分异程度较高等特点,为高钾钙碱性岩石,属准铝质—过铝质高钾钙碱性花岗岩;其轻稀土强富集,重稀土分馏较弱,显示明显负铕异常(δEu=0.71~0.74)。Rb、Pb和高场强元素中Th、U、Hf、La、Ce、Nd富集,Ba、Sr及Nb、Y、Ta、Ti、P明显亏损。岩体成因上属壳源型花岗岩,为陆内造山环境下的地壳重熔形成的花岗岩类,源岩为泥质岩和杂砂岩。The Liangwan pluton is located in the central part of the East Qinling-Dabie metallogenic province,and its lithology consists of porphyritic diorite and porphyritic biotite-bearing diorite.The LA-ICP-MS U-Pb ages of zircons are(130±1)Ma(n=24,MSWD=0.45)and(135±2)Ma(n=23,MSWD=5.5),indicating that the Liangwan rock mass is formed in the Early Cretaceous period.Liangwan rock mass has high SiO_(2)content(68.06%-74.78%),rich in K and poor in Na,and a high degree of differentiation.It is a high potassium calcium alkaline rock and belongs to quasi aluminum to peraluminous high potassium calcium alkaline granite.It exhibits strong enrichment of light rare earth elements and weak fractionation of heavy rare earth elements,displaying significant negative europium anomalies(δEu=0.71-0.74).Rb,Pb,and high field strength elements Th,U,Hf,La,Ce,Nd are enriched while Ba,Sr,Nb,Y,Ta,Ti,and P are significantly depleted.The rock formation belongs to crustal granite,which is a type of granite formed by crust remelting in an intracontinental orogenic environment.The source rocks are mudstone and sandstone.

关 键 词：梁湾岩体 锆石U-PB年龄 地球化学特征 河南泌阳 

分 类 号：P588.12[天文地球—岩石学] P597[天文地球—地质学]