川西金川县李家沟超大型锂辉石矿床的地质特征及找矿标志

The Geological Characteristics and ore indicators of Lijiagou Super-large Spodumene Deposit in Jinchuan County,Western Sichuan

李家沟超大型锂辉石矿床是近年来在川西可尔因稀有金属花岗伟晶岩田取得的重要找矿突破。该矿床产于可尔因花岗岩体外接触带内,其围岩为由热接触变质作用形成的角岩、片岩。在矿区范围内共发现了15条工业矿体,矿体呈脉状、透镜状赋存于锂辉石钠长石花岗伟晶岩中,长210m~520m,厚14m~32m,倾向北-北西,倾角45。~80。。矿石以细粒伟晶结构、中粒伟晶结构,块状构造为主。矿石矿物主要为锂辉石和锂云母,脉石矿物主要为钠长石和石英,矿石中有用组分主要为氧化锂,并伴生有铌、钽、铍和锡组分,可尔因岩体外接触带2km~7km范围内的背斜核部、节理裂隙发育的部位是伟晶岩型锂矿床的主要产出区域,伟晶岩转石、正地貌是找寻伟晶岩型锂矿床的直接标志。

Lijiagou super-large spodumene deposit is an important ore prospecting breakthrough made in recent years in the Keeryin rare metal granite pegmatite field,western Sichuan.This ore deposit is produced in the contact zone of the Keeryin granitic body.The surrounding rock are hornstone and schist,formed by thermal contact metamorphism.In the mining area,15 industrial orebodies were found.The orebodies are vein-like and lenticular in the spodumene-feldspar granite pegmatite,with a length of 210 m~520 m and a thickness of 14 m~32 m.The ore body is inclined to the north or northwest,with an inclination of 45°~80°.Ore is mainly fine-grained and medium-grained pegmatite structure,massive structure.Minerals are mainly spodumene,lithium mica,gangue minerals are mainly albite,quartz.The useful components in the ore are mainly Li2 O,and associated components such as Nb,Ta,Be,Rb,Sn.Within the contact area of the Keeryin rock mass with the range of 2 km~7 km,the position of anticlinal nucleusthe and joint fissure development are the main output area of the pegmatite type lithium deposit.Pegmatite turn stone and positive landform is a direct sign for the search for pegmatite-type lithium deposit.