桂北地区寨滚锡多金属矿区闪长玢岩的矿物学特征及其地质意义  

Mineralogical characteristics of diorite porphyrite at Zhaigun tin polymetallic mining area in North Guangxi and its geological significance

作　　者：崔安民 覃小锋[1,2] 王宗起[3] 马收先[3] 宫江华[3] 李东 CUI Anmin;QIN Xiaofeng;WANG Zongqi;MA Shouxian;GONG Jianghua;LI Dong(College of Earth Science,Guilin University of Technology,Guilin 541006,China;Guangxi Key Laboratory of Exploration for Hidden Metallic Ore Deposits,Guilin University of Technology,Guilin 541006,Guangxi,China;Institute of Mineral Resources,Chinese Amdemy of Geological Sciences,Beijing 100037,China)

机构地区：[1]桂林理工大学地球科学学院,广西桂林541006 [2]桂林理工大学广西隐伏金属矿产勘查重点实验室,广西桂林541006 [3]中国地质科学院矿产资源研究所,北京100037

出　　处：《矿产与地质》2021年第4期680-692,共13页Mineral Resources and Geology

基　　金：中国地质调查局“重要矿种关键问题调查与矿产地质专题填图试点”(DD20160124)项目资助。

摘　　要：寨滚锡多金属矿赋存于桂北宝坛地区寨滚花岗岩体的外接触带,其围岩是一套中—基性杂岩体,主要由(辉长)辉绿岩-辉绿玢岩和闪长(玢)岩组成,以闪长玢岩为主。利用电子探针(EMPA)对闪长玢岩进行矿物化学分析测试。测试结果表明,角闪石和黑云母的结晶温度范围分别为662℃~705℃和550℃~650℃;结晶压力分别为0.40 GPa~0.70 GPa和0.18 GPa~0.26 GPa,相对应的形成深度分别为13.16~23.17 km和5.95~8.45 km。综合特征表明,寨滚中—基性杂岩体的原生岩浆主要来源于幔源,在高温条件下幔源岩浆底辟上侵到地壳较深部位(13.16~23.17 km)时,与壳源性质的长英质岩浆发生壳-幔岩浆混合作用,形成的新岩浆快速上升至地壳浅部(5.95~8.45 km)发生冷凝结晶分异作用,最终形成现在的具壳-幔混合性质的寨滚中—基性杂岩体。Zhaigun tin polymetallic deposit is located at the outer contact zone of Zhaigun granite in Baotan area,North Guangxi.The surrounding rock is a set of intermediate-basic complex,which is mainly composed of(gabbro)diabase-diabase porphyrite and diorite porphyrite,and diorite porphyrite is the main part.The mineral chemical analysis of dioriteporphyrite is carried out by EMPA.The test result shows that the crystallization temperature of amphibole and biotite are 662℃-705℃and 550℃-650℃.The crystallization pressure are 0.40 GPa-0.70 GPa(corresponding to the depth of 13.16-23.17 km),and 0.18 GPa-0.26 GPa(corresponding to the depth of 5.95-8.45 km).The comprehensive feature indicates that the primary magma of Zhaigun intermediate-basic complex is mainly derived from mantle source,as the mantle source magma penetrates into the deeper part of the crust(13.16-23.17 km)under the condition of high temperature,the crust-mantle magma mixting occurs with felsicmagma of crust-derived nature,afterwards the new magma rises rapidly to the shallow part of the crust(5.95-8.45 km)and crystallizes and differentiates,and the present Zhaigunintermediate-basic complex is finally formed with the characteristics of crust-mantle mixture.

关 键 词：中基性杂岩体 矿物化学成分 壳-幔岩浆混合作用 寨滚锡多金属矿区 桂北宝坛地区 

分 类 号：P588.134[天文地球—岩石学]