西藏林子宗群分布区浅成低温热液型矿床岩帽地球化学特征及找矿前景——以斯弄多银多金属矿床为例  

Geochemical Characteristics and Prospecting of Lithocaps from Epithermal Deposits in the Linzizong Group Volcanic Rocks:a Case study of the Sinongduo Silver Polymetallic Deposit,Tibet

作　　者：吴鑫 WU Xin(College of Earth Science,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059

出　　处：《世界有色金属》2021年第3期81-82,共2页World Nonferrous Metals

摘　　要：酸性蚀变岩帽常与浅成低温热液型矿床相关,是一种重要的找矿标志。为了研究斯弄多矿区岩帽对找矿的指示作用,本文对斯弄多矿区地表出露的岩帽采样进行全岩地球化学研究,判断其是否具有成矿潜力。结果表明,斯弄多岩帽具有明显的富硅富铝的特点,稀土元素总量变化较大,呈现明显的右倾分布特征,Eu和Yb具有明显的负异常。岩帽中Th、U、Nb、Ta、Zr、Hf等高场强元素明显富集,Rb、K、P、Sn等大离子亲石元素明显亏损。Au与Al_(2)O_(3),As,Fe_(2)O_(3)T成正相关,与SiO_(2)含量呈负相关,表明该矿床地表浅部可能存在系统金矿化事件,Au可能赋存于黄铁矿、毒砂或者富铝质的蚀变矿物中。斯弄多岩帽与林子宗群火山岩具有相似的地球化学特征,岩帽原岩为林子宗群火山岩,多源的流体参与了其形成过程。Lithocap is often associated with epithermal deposit,and is an important indicator of mineralization.In order to study the role of the lithocap in mineral prospecting,we conduct the whole-rock geochemical studies of the lithocap from the Sinongduo deposit to determine whether it has potential for mineralization.The results show that the Sinongduo lithocap is obviously rich in Si and Al,and the total amount of REE elements varies greatly,showing an obvious right-tending distribution,with obvious negative anomalies in Eu and Yb.While Th,U,Nb,Ta,Zr,Hf and other high field strength elements in the lithocaps are obviously enriched,and Rb,K,P,Sn and other large ionophile elements are obviously deficient.Au is positively correlated with Al_(2)O_(3),As,Fe_(2)O_(3)T and negatively correlated with SiO_(2)content,suggesting that there could be a gold mineralization event in the shallow the deposit,and Au may be hosted in pyrite,arsenopyrite or aluminite-rich alteration minerals.The lithocap of the Sinongduo has similar geochemical characteristics to the linzizong group volcanic rock,and the protolith of the lithocap is the linzizong group volcanic rock,with multiple sources of fluids involved in its formation.

关 键 词：岩帽 斯弄多银多金属矿床 浅成低温热液型矿床 地球化学 

分 类 号：P618.51[天文地球—矿床学]