安徽金寨地区花岗岩类放射性地球化学特征及岩石圈热结构研究  

Radioactive Geochemical Characteristics of Granitoids and Thermal Structure of Lithosphere in Jinzhai Area,Anhui Province

作　　者：豆保娜 王安东[1,2] 万建军[1,2] 丁宁[3] DOU Bao-na;WANG An-dong;WAN Jian-jun;DING Ning(State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China;School of Earth Sciences, East China University of Technology, Nanchang 330013,China;Geological Survey of Anhui Province, Hefei 230001,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,江西南昌330013 [2]东华理工大学地球科学学院,江西南昌330013 [3]安徽省地质调查院,安徽合肥230001

出　　处：《东华理工大学学报（自然科学版）》2022年第3期234-242,共9页Journal of East China University of Technology(Natural Science)

基　　金：国家重点研发计划项目(2018YFA0404104);核资源与环境国家重点实验室自主基金项目(Z1912);国家自然科学基金项目(41874100);江西省重点研发计划项目(20203BBG72W011)。

摘　　要：为研究安徽金寨地区花岗岩类放射性地球化学特征及岩石圈热结构特征,对该地区采集的地表及钻孔花岗岩类样品进行放射性生热元素含量、岩石密度和岩石热导率测试,同时收集前人发表的金寨地区花岗岩类放射性生热元素数据进行分析。研究结果显示:金寨地区花岗岩类U、Th、K2O平均含量分别为10.84×10-6、35.07×10-6和4.82%;岩石放射性生热率的平均值为5.36μW/m3,其主要来自U和Th的放射性衰变热,K的热贡献率相对较低,一般不超过10%,U的热贡献率稍大于Th;岩石热导率的平均值为3.142 W/(m·K),与世界范围内花岗岩类热导率平均值相近。综合已有的地球物理、地球化学及地热学等资料,推断金寨地区地幔热流值略低于地壳热流值,属于“热壳冷幔”型岩石圈热结构。In order to ascertain the radioactive geochemical characteristics and lithospheric thermal structure characteristics of granitoids in Jinzhai area,Anhui Province,the radioelement content,rock density and rock thermal conductivity of the surface and borehole granitoids samples in Jinzhai area,Anhui Province were measured,and the data of radioelement content of granitoids in Jinzhai area previously published were also collected.The results show that the average contents of U,Th and K2O in granitoids in Jinzhai area are 10.84×10-6,35.07×10-6 and 4.82%,respectively.The average radiogenic heat production is 5.36μW/m3.The main thermal contribution of rocks comes from the radioactive decay heat of U and Th,while that of K is relatively lower,generally less than 10%,and that of U is slightly higher than that of Th.The average thermal conductivity of rocks is 3.142 W/(m·k),which is close to the average thermal conductivity of granitoids in the world.Based on the existing geophysical,geochemical and geothermal data,it is concluded that the contribution of mantle heat flow value in Jinzhai area is slightly lower than that of crust heat flow value,which indicates the lithospheric thermal structure is the type of"hot crust and cold mantle".

关 键 词：花岗岩类 放射性生热率 岩石圈热结构 金寨地区 

分 类 号：P595[天文地球—地球化学]