关键词: 朱溪钨矿, 矽卡岩, 白钨矿, 榍石U-Pb定年

Abstract: The Zhuxi tungsten deposits are superlarge ore deposits， discovered in recent years in the eastern segment of Jiangnan
orogenic belt. The ore bodies of the Zhuxi deposits mainly occur in the skarn and skarnized marble at the contact zone between
Yanshan intrusive rocks and carbonate. To better understand the characteristics and genesis of Zhuxi tungsten deposits, we collected
both granites and skarns samples, and carried out research on petrology, mineralogy, geochemistry and chronology. The petrological
and geochemical characteristics of the biotite granites are calc-alkaline and peraluminous，enriched in Rb，U，Ta，and depleted in
Ba，Nb，Sr and Ti. The rare earth elements are characterized by the relatively low total content with a slightly rightly-dipping REE
pattern. Electron microprobe analyses reveal that the garnet is mainly composed of grossularite-andradite, and the pyroxene mainly
belongs to diopside-andradite series. Sheelite coexists with many F-rich minerals such as fluorite, apatite, titantites, and vesuvianite.
The F-enriched ore-forming fluid facilitates the transfer of W and the mineralization of scheelite in the Zhuxi deposits. The fluid
characteristic reflected by the REE distribution curve and Mo content variations of scheelite indicate that the mineralization
environment of zhuxi tungsten deposits changed from oxidation to reduction environment in the skarn stage. In-situ U-Pb dating of
titanite by LA-ICP-MS shows that titanite from the skarn sample yields a weighted mean 206Pb /238U age of 153±2 Ma. The main
mineralization event occured in the Yanshanian, which is consistent with the age of Zhuxi granites .

Key words: Zhuxi tungsten deposits, skarn, scheelite, titantite U-Pb daing