川西西康群酸性侵入岩地质、地球化学特征及找矿意义  

Geological and Geochemical Characteristics and Prospecting Significance of Acid intrusive Rocks in Xikang Group,Western Sichuan

作　　者：田光昊 侯红星 邵兴坤 孙肖 胡新茁 马永君 王晓阳 TIAN Guanghao;HOU Hongxing;SHAO Xingkun;SUN Xiao;HU Xinzhuo;MA Yongjun;WANG Xiaoyang(Langfang Natural Resources Comprehensive Survey Center,China Geological Survey)

机构地区：[1]中国地质调查局廊坊自然资源综合调查中心

出　　处：《现代矿业》2021年第12期91-97,共7页Modern Mining

摘　　要：川西西康群酸性侵入岩位于扬子陆块西缘的雅江残余盆地西侧,侵位于三叠系西康群两河口组砂板岩中,具砷多金属矿化特征。通过对川西地区4616高地酸性侵入岩岩相学、岩石地球化学特征的系统性研究,查明与成矿有关的酸性侵入岩岩石成因演化及其构造背景。4616高地花岗侵入岩SiO_(2)含量平均为74.33%,属碱性岩类,ACNK平均值为1.05,呈过铝质的特征,具有富碱、Al_(2)O_(3)、Rb、Hf和相对较低的CaO、Fe_(2)O_(3)、MgO、Sr,具有明显的负Eu异常,明显亏损Nb、Ti等高场强元素。4616高地花岗侵入岩为Ⅰ型花岗岩,构造背景具有后碰撞型花岗岩特征,主体为壳源物质重熔,可能存在幔源物质的加入。通过对川西地区4616高地酸性侵入岩岩相学、岩石地球化学特征的系统研究,查明本区成矿地质条件有利,找矿潜力较大。主攻矿床类型为岩浆热液型、构造蚀变岩型。The acidic intrusive rocks of the Xikang Group in western Sichuan are located in the west side of the Yajiang residual basin on the western margin of the Yangtze block,and are in the Triassic Xikang Group Lianghekou Formation sandy slate,with arsenic polymetallic mineralization characteristics.Based on the systematic study of petrography and geochemical characteristics of acidic intrusive rocks in the 4616 highland of western Sichuan,the genetic evolution and tectonic setting of acidic intrusive rocks related to mineralization are identified.The average SiO_(2) content of 4616 highland granite intrusive rock is 74.33%,which belongs to alkaline rock.The average ACNK is 1.05,which is peraluminous.It is rich in alkali,Al_(2)O_(3),Rb,Hf and relatively low CaO,Fe_(2)O_(3),MgO,Sr,with obvious negative Eu anomaly and obvious loss of high field strength elements such as Nb and Ti.The granite intrusive rocks in the 4616 highlands are type Ⅰ granites the tectonic background is characterized by post-collisional granite.The main body is the remelting of crust-derived materials,and there may be the addition of mantle-derived materials.Based on the systematic study of petrography and geochemistry of acidic intrusive rocks in the 4616 highland of western Sichuan,it is found that the metallogenic geological conditions are favorable and the prospecting potential is large.The main deposit types are magmatic hydrothermal type and tectonic altered rock type.

关 键 词：酸性侵入岩 地球化学特征 找矿意义 

分 类 号：P618.2[天文地球—矿床学]