摘要
江西省上饶县金竹坪钼多金属矿区位于北武夷梨子坑(铜钹山)火山岩盆地,该火山岩盆地是北武夷地区火山岩分布区,本区新发现了较大规模的钼多金属矿化。金竹坪矿区位于该火山岩盆地的近中心位置,钼(钨)多金属矿体又主要赋存于隐伏(半隐伏)花岗岩与其上覆火山岩的接触带,矿化与接触带产状一致。文章通过在该接触带的蚀变花岗岩型矿体中采集的5件辉钼矿样品进行铼-锇同位素定年测试,获得了辉钼矿等时线年龄为(135.5±5.7)Ma,其加权平均方差(MSWD)为16,表明成矿作用发生在中生代白垩纪。由于矿体赋存于岩体顶突部位的蚀变花岗岩中,预示成矿为花岗岩侵入的同期或稍后,即钼钨铅锌银成矿与燕山期花岗岩侵入活动密切相关,这对于火山岩内寻找与侵入岩有关的矿产提供了新的思路。
The Jinzhuping molybdenum-polymetallic deposit from Shangrao,Jiangxi province is located in Lizi volcanic basin,which is one of volcanic rock area in the northern Wuyi and in which larger-scale of molybdenum-polymetallic mineralization was found. The Jinzhuping mine is close situated to the center of the Basin and molybdenum-polymetallic ore bodies mainly occurred within contact zone between underlying granite and overlaid volcanic rock,following the shape of the zone. Re-Os isotope dating for molybdenite from the contact zone yield an isochron age of (135.5±5.7) Ma with MSWD=16,which indicates that the mineralization took place at the Cretaceous. The ore body occurred adjacent to the granite,thus it is inferred that mineralization stage is syngenetic or slightly later than emplacement of the granite,suggesting that mineralization of Mo,W,Pb,Zn and Ag was closely related to emplacement of the Yanshan period granites,and providing a new model for prospecting intrusive-related resource inside the volcanic rocks.
引文
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