治岭头金银矿床的成矿时代

治岭头金银矿床是产于浙西南元古界变质地体内的含金韧性剪切带型大型矿床。翔实的宏观地质调查，相关地质体的角闪石、锆石和矿石矿物、矿石石英包裹体液体的４０Ａｒ３９Ａｒ法、Ｕ－Ｐｂ法、Ｒｂ－Ｓｒ等时线法等同位素测年，取得可靠的成矿年代学资料。地质体的相互穿切、包容关系和同位素年龄资料表明，成矿是长期累进式演化、积累的结果，而形成工业矿体的主矿化阶段为燕山早期。

THE METALLOGENETIC EPOCH OF ZHILINTON GOLD-SIVER DEPOSIT

Zhilinton gold-siver deposit, surrounded by Proterozoic metamorphic rocks and controlled by the ductile shear zones, is a large one. In the mine area. there are two-strata geological units: a basement formed out of Proterozoic hornblendite facies assemblagas, which was covered by upper Jurassic middle acid-acid volcanic rocks. Intrusive rocks were seen in almost every geological time. The ductile shear zones in the basement were evolved into ductile-brittle fractures or Riedel shears which controlled the gold-silver ore bodies, meanwhile, volcanic structures formed with volcanic actirity in Mesozoic era controlled a lear-zinc-pyrety and base matal sulfide ore body. With regared to the timing of the gold-silver deposit, there are a lot of different news, so, on the basis of having surveied and decided the relative timing, we sampled from the relative geo- logic bodies and assaied the amphible, zircon as well as fluid inclisions in quarty with respective isotope method of 40Ar-39Ar, U-Pb and Rb-Sr isochronism. The finding indicated that the ore -forming process suffered a long time evolution and accumulation and, was dated from 227 to 82. 5 m. y. in. which the economic ore bodies were timed within 165-140 m. y., The mineralition has sometiong to do with subvolacangenic ore-forming process prior to large volcanic activity in early Yenshan movement, and thereupon, the result is a encouragement for us to find out more such gold-silver deposits in Mesozoic volcanic rocks, in Zhejiang and Fujia provinces.