冀东宽城地区大石柱花岗岩LA-ICP-MS锆石U-Pb测年及其地质意义  

LA-ICP-MS zircon U-Pb dating and geological significance for the Dashizhu granite in Kuancheng area,eastern Hebei Province

作　　者：程先钰 何鹏 滕飞 吴海鑫 田辉 孙立新 CHENG Xianyu;HE Peng;TENG Fei;WU Haixin;TIAN Hui;SUN Lixin(Tianjin Centre,China Geological Survey(North China Center for Geoscience Innovation),Tianjin 300170,China;Laboratory of Non Fossil Energy Minerals,Tianjin Center,China Geological Survey,Tianjin 300170,China;Hebei GEO University,Shijiazhuang 050000,China)

机构地区：[1]中国地质调查局天津地质调查中心(华北地质科技创新中心),天津300170 [2]中国地质调查局天津地质调查中心非化石能源矿产实验室,天津300170 [3]河北地质大学,石家庄050000

出　　处：《华北地质》2025年第1期58-66,77,共10页North China Geology

基　　金：中国地质调查局项目“燕山—太行成矿带区域地质调查(DD20240035)”。

摘　　要：【研究目的】冀东青龙—宽城地区发育多期花岗质岩浆活动,相较于冀东地区最大的中生代侵入体的都山岩体,前人对大石柱岩体的研究相对薄弱,并对其形成的时代争议较大。本文旨为探讨冀东宽城大石柱岩体的形成时代及地质意义。【研究方法】笔者对大石柱岩体进行了LA-ICP-MS锆石U-Pb测年,重新厘定了大石柱侵入体的形成时代,并通过区域地质调查对大石柱岩体进行划分。【研究结果】初步将大石柱岩体划分为三期,其中二长花岗岩期按照矿物粒度大小分为中心相和边缘相;本次选取两个二长花岗岩进行研究,获得了226 Ma和214 Ma的成岩年龄,时代归属为中生代晚三叠世。【结论】结合区域对比及综合研究,初步认为宽城大石柱子岩体为西南部都山岩体的北东向侵入延伸,二者实为同一岩体。其结果为冀东地区寻找金矿成矿带开辟新思路、新方向。[Objective]Multiple periods of granitic magmatic activity have developed in the Qinglong Kuancheng area of eastern Hebei Province,previous studies on the Dashizhu rock mass are relatively weak compared to the Dushan pluton,which is the largest Mesozoic intrusive rock in the eastern Hebei province.The formation age of the Dashizhu rock mass has always been controversial.This article aims to explore the formation age and geological significance of the Dashizhu rock mass in Kuancheng,eastern Hebei Province.[Methods]This article conducted LA-ICP-MS zircon U-Pb dating on the Dashizhu rock mass in Kuancheng County,Chengde,redefine the formation age of the intrusion body of the Dashizhu,which is disintegrated through regional geological survey.[Results]The Dashizhu pluton is divided into three stages.The stage of adamellite is divided into central and marginal phases according to mineral particle size,the authors selected two monzonitic granites diagenetic ages of 226 Ma and 214 Ma,which belong to the Late Triassic of the Mesozoic era.[Conclusions]Based on regional comparison and comprehensive research,it is preliminarily believed that the Kuancheng Dashizhu rock mass is a northeast intrusive extension of the southwestern Dushan pluton,the result will provide new ideas for searching gold mineralization zones in the eastern Hebei Province.

关 键 词：冀东地区 大石柱岩体 锆石U-PB测年 晚三叠世 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]