西昆仑大红柳滩矿集区伟晶岩型锂铍矿床找矿模型及意义

Prospecting Model of Pegmatite Type Lithium Beryllium Deposit in Dahongliutan Ore Concentration Area of West Kunlun and Its Geological Implications

大红柳滩一带锂铍矿是近年来新疆地质矿产勘查开发局在西昆仑锰、铅锌矿取得找矿突破后又取得的一项稀有金属矿重大突破。该矿位于西藏-三江造山系巴颜喀拉地块康西瓦-泉水沟前陆盆地,处于大红柳滩锂铍稀有金属矿带。已发现有大红柳滩、卡拉喀、雪龙山、龙门山等多个大中型矿床。矿体赋存于晚三叠世二云母花岗岩、黑云母花岗岩外接触带巴彦喀拉山群顺层产出的伟晶岩脉中。NW向区域性大断裂康西瓦断裂和大红柳滩-郭扎错断裂控制着花岗岩的分布。走向节理和斜交节理控制着锂辉石伟晶岩脉的产出位置和规模大小。含锂矿物主要为锂辉石,次为少量磷锂铝石、锂电气石、锂云母、磷铁锂矿等,Li_(2)O品位1%~3%,共伴生BeO品位0.041%~0.061%。建立了“中生代花岗岩-伟晶岩+NW向韧脆性断裂带+地层+锂铍化探异常+铁染羟基蚀变”五位一体找矿模型,并提出了大红柳滩岩体南西侧和靠近中生代酸性岩体外接触带巴彦喀拉山群顺层产出的伟晶岩脉带深部及岩体NW、SE向延长线上是今后勘查的新目标。认为大红柳滩、雪龙山、龙门山等大中型矿床是大红柳滩地区超大型锂铍矿床的不同矿段,区域具超大型锂铍矿成矿潜力。

The lithium beryllium deposit in Dahongliutan area is a major breakthrough of rare metal deposit in recent years after Xinjiang Bureau of Geology and mineral resources made a breakthrough in the exploration of manganese and lead zinc deposits in West Kunlun.It is located in Kangxiwa Quanshuigou foreland basin of Bayan Har block of Tibet Sanjiang orogenic system and in Dahongliutan lithium beryllium rare metal ore belt.There are many large and medium sized deposits such as Dahongliutan,Karaka,Xuelongshan and Longmenshan.The ore bodies occur in the pegmatite dikes of the Bayankala group in the outer contact zone of the Late Triassic two mica granite and biotite granite.The Kangxiwa fault and Dahongliutan guozhaco fault control the distribution of granite.Strike joints and oblique joints control the location and scale of spodumene pegmatite dikes.The lithium bearing minerals in the ore are mainly spodumene,followed by a small amount of limonite,tourmaline,lepidolite,limonite,etc.The Li_(2)O grade is mostly 1%~3%,and the as-sociated BeO grade is 0.041%~0.061%.According to the five in one prospecting model of"Mesozoic granite pegmatite+NW trending ductile brittle fault zone+stratum+lithium beryllium geochemical anomaly+iron stained hydroxyl alteration",the author proposed that the new exploration targets in the future are the south-west side of Dahongliutan rock mass,the deep part of pegmatite vein belt along the bedding of Bayankala mountain group near the outer contact zone of Mesozoic acid rock mass,and the NW and SE extension line of the rock mass.It is considered that Dahongliutan,Xue-longshan,Longmenshan and other large-medium-sized deposits are different ore sections of super large-scale lithium beryllium deposits in Dahongliutan area,the area has super large lithium beryllium mineralization potential.