川西连龙夕卡岩型锡、银多金属矿床成矿地质特征

连龙夕卡岩型锡银多金属矿床作为义敦岛弧锡银矿化的典型代表，成矿作用主要发生在夕卡岩化阶段，矿床类型属钙夕卡岩型Sn-Ag-Bi多金属矿床。S、Pb同位素研究表明，矿床中成矿物质主要来自花岗岩体。

Metallogenic Geological Characteristics of the Lianlong Skarn Type Sn-Ag Polymetallic Deposit in Western Sichuan

In Late Yanshanian movement, Yidun arc evolved into the arc-continent collision stage, and a large-scale post-orogenic A-type granitic magmatic activity occurred behind the arc area, accompanied by widespread Sn-Ag polymetallic mineralization. As a typical example of Sn-Ag polymetallic mineralization, the Lianlong skarn-type Sn-Ag polymetallic deposit consists of four ore-forming stages accompanied by five types of alterations, viz., alkaline metasomatism, skarnization, greisenization, phyllic sericitization, and marbleization. The four metallogenic associations are cassiterite, cassiterite + native bismuth + polymetal sulfides, cassiterite + scheelite + sulfides and pyrite + sulfides The ore-forming process was completed mainly at the skarnization stage. The deposit is of calc-skarn Sn-Ag-Bi polymetallic type. Sphalerite, galena, chalcopyrite and arsenopyrite from the deposit give δ34S values of -9.5‰, -9.9‰, -10.4‰ and -10.5‰ respectively, being very close to the δ34S value of granite (-8.1‰). Pb isotopic measurement of ores gives 206Pb/204Pb,207Pb/204Pb and208Pb/204Pb of 18.6184～18.7099, 15.6300～15.738, and 38.8126～39.126 respectively, consistent with the granite values (18.9585～19.206, 15.6534～15.7066 and 38.9267～39.2110). All these data indicate that the ore-forming matter was mainly derived from the granite.