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位于羌塘南缘多龙矿集区内的荣那斑岩-高硫型浅成低温热液Cu-(Au)矿床系近年来中铝西藏与西藏地质五队合作勘查取得重大找矿突破的铜矿床,控制资源量已达超大型规模,但对该矿床的成因类型仍存在争议。本文根据详细的钻孔岩芯、结合光学显微镜、扫描电镜观察、硫化物的电子探针分析,认为该矿床成矿与早白垩世花岗闪长斑岩有关。矿体主要产于下中侏罗统色哇组长石石英砂岩和成矿斑岩体中,矿体呈东西走向、南倾的隐伏状,延深巨大,金属矿化以铜为主,伴有金、银矿化,偶见钼矿化。热液蚀变具有两阶段蚀变:与斑岩型矿化有关的黑云母化、角岩化、硅化-绢云母化及硅化-伊利石-绿泥石化以上部叠加的高级泥化,蚀变分带明显。相应的该矿床具有斑岩型细脉浸染状矿化和以硫砷铜矿为特征的高硫型矿化,含铜矿物主要分为4个带,大致与蚀变分带相对应,下部主要为斑铜矿-黄铜矿;过渡带以斑铜矿-铜蓝组合为特征;中上部为蓝辉铜矿-砷黝铜矿-硫砷铜矿组合;顶部主要由为辉铜矿-蓝辉铜矿组成。总体上,矿床中上部为Cu-S体系、向下转变Cu-Fe-S体系。与其它类似矿床相比,该矿床硫化物中以富Zn、贫金为特征。综上认为该矿床为斑岩-高硫型浅成低温热液Cu-(Au)套合成矿的典型实例,其勘查突破为羌塘南缘火山岩区及覆盖区的找矿打开了一扇窗口。
The Rongna porphyry-high-sulfur epithermal Cu- (Au) deposit, located in the Dulong ore district on the southern margin of the Qiangtang area, has made major exploration breakthroughs in the exploration of the cooperation between the Chinalco-Tibet and the five geological teams in Tibet in recent years Copper deposits, control of resources has reached a large scale, but the genetic types of the deposit is still controversial. Based on detailed core drilling, combined with optical microscopy, scanning electron microscopy and electron probe analysis of sulfide, the mineralization of the deposit is considered to be related to the Early Cretaceous granodiorite porphyry. The ore body is mainly produced in the Lower Middle Jurassic feldspar quartzite sandstone and metallogenetic porphyry body. The ore body is in the east-west direction and the south dip is invisible, with a great depth of extension. The metal mineralization is mainly copper, Gold, silver mineralization, occasionally molybdenum mineralization. Hydrothermal alteration has two stages of alteration: biotitization, hornification, silicification-sericification and silicification related to porphyry mineralization - advanced illite-chloritization with advanced mudding and alteration Zoning obvious. Correspondingly, the deposit is characterized by porphyry disseminated mineralization and high-sulfur mineralization characterized by arsenic-bearing copper deposits. The copper-bearing minerals are mainly divided into four zones, roughly corresponding to alteration zones, and the lower part Mainly composed of behenite-chalcopyrite; the transitional zone is characterized by a combination of bornite-copper-blue zone; the middle-upper part is composed of blue-chalcopyrite-arsenite-tetrahedrite-copper arsenic-copper deposit; the top is mainly composed of chalcopyrite- Blue Hui copper composition. In general, the upper part of the deposit is a Cu-S system, down-converting the Cu-Fe-S system. Compared with other similar deposits, the sulfide in the deposit is characterized by Zn-rich and lean-gold. In summary, this deposit is considered as a typical example of porphyry-high-sulfur epithermal Cu- (Au) mineralization. The prospecting breakthrough opened a window for volcanic rock area and coverage area in southern margin of Qiangtang .