四川甲基卡锂矿伟晶岩转石分布区“3定2参”大比例尺填图法及其在青藏高原应用的意义  

The “3D2R-BP” large scale mapping method for blocks of pegmatite in the Jajika deposit, western Sichuan, and significance of its application in the Qinghai-Tibet Plateau

作　　者：刘善宝[1] 王成辉[1] 王登红[1] 代鸿章 马圣钞[1] 于扬[1] 潘蒙[2] 郝雪峰[2] 杨荣[2] LIU Shanbao;WANG Chenghui;WANG Denghongn;DAI Hongzhang;MA Shengchao;YU Yang;PAN Meng;HAO Xuefeng;YANG Rong(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resource,CAGS,Beijing,100037;Geological Survey Institute of Sichuan Province,Chengdu,610081)

机构地区：[1]自然资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所,北京100037 [2]四川省地质调查院,成都610081

出　　处：《地质学报》2020年第1期326-332,共7页Acta Geologica Sinica

基　　金：国家重点研发计划(编号2017YFC0602700,2017YFC0602701);中国地质调查项目(编号DD20190379);中央级公益性科研院所基本科研业务费项目(编号JYYWF20183701;JYYWF20183704)联合资助成果

摘　　要：我国西部地区无论是新疆阿尔泰还是地处青藏高原的西昆仑地区或是松潘-甘孜成矿带,都是我国伟晶岩型矿床找矿远景区,但要么剥蚀严重,要么第四系覆盖,难以找到好的地质露头。本文以地处青藏高原东南缘的川西甲基卡矿田为例,通过近10年来的实践,探索出一套在第四系覆盖严重但又有伟晶岩转石分布地区的填图找矿方法--"3定2参"1∶2000伟晶岩转石填图法,即:定伟晶岩转石类型、尺度、密度,参考矿区内伟晶岩脉产状和地形条件。实践证明,该方法能够快速有效识别伟晶岩转石类型(冰碛物、坡积物和原地或半原地型),并可进一步确定第四系覆盖区内伟晶岩脉的类型、产状及规模,为钻探工程部署提供依据。2019年在甲基卡经8个钻孔验证,在日西柯第四系覆盖区内发现16条花岗伟晶岩脉,其中锂辉石伟晶岩脉10条,实现了新的找矿突破。这一方法同样在可尔因矿集区适用,并指导2019年"松潘-甘孜成锂带锂铍多金属大型资源基地综合调查评价"项目在上述两个地区实施钻探验证,初步探获新增氧化锂资源量超过15万吨,值得进一步推广应用。Despite the occurrence of promising pegmatite deposits in the Altay of Xinjiang,West Kunlun and the Songpan-Ganzi metallogenic belt,Western China,it is difficult to find a good geological outcrop because of the serious denudation or quaternary coverage.In this study we have investigated the Rixike deposit in the Jiajika mining area as test case to address the above challenge.We have applied an innovative 1∶2000 mapping technique involving"three determinations and two references"for the blocks of pegmatite i.e.determined the type,scale and density of pegmatite transformation to characterize the occurrence and topographic conditions of pegmatite vein in the mining area-a large scale mapping strategy referred to as the"3 D2 R-BP"method.The resulting preliminary determination of the type,occurrence and scale of pegmatite vein in the quaternary covered area provided a basis for the deployment of drilling equipment.Following confirmatory data from the drilling holes,sixteen granitic pegmatite veins,including ten spodumene-bearing pegmatite veins,have been identified in the quaternary covered area of the Rixike.This study has not only proved the applicability of the"3 D2 R-BP Mapping"method,but also provided a breakthrough in the exploration of new deposits.In addition,this method is also applicable to the Keryin ore field in locating and deep mining of pegmatites under quaternary coverage.In 2019,more than 150000 tons of lithium resources have been added through the project"Comprehensive investigation and evaluation of large-scale resource base of lithium beryllium polymetallic in Songpan-Ganzi lithium belt"demonstrating the wider applicability of this method.

关 键 词：“三定两参” 伟晶岩转石 第四系覆盖区 日西柯 找矿突破 

分 类 号：P618.71[天文地球—矿床学]