中文摘要:安徽省金寨县沙坪沟钼矿是新发现的超大型斑岩型钼矿床。文章介绍了该矿床的基本地质特征,并对其进行了精确的辉钼矿Re-Os同位素年代学测定。结果表明,沙坪沟钼矿辉钼矿模式年龄为(112.2±1.7)~(113.9±1.7) Ma,加权平均年龄为(113.18±0.54) Ma,MSWD=0.39;等时线年龄为(113.21±0.53) Ma,MSWD=0.64,表明沙坪沟钼矿形成于早白垩世晚期。结合区域上已有的岩体高精度年代学数据、矿床辉钼矿Re-Os年代学数据和钼矿产出的大地构造位置,将东秦岭-大别山中生代钼成矿作用划分为2期4个阶段: 印支期(260~205 Ma)和燕山期的晚侏罗世—早白垩世早期(148~138 Ma),早白垩世中期(135~119 Ma)和早白垩世晚期(116~105 Ma),其中,以燕山期钼成矿作用最为强烈。
中文关键词:地球化学 辉钼矿Re-Os同位素测年 钼成矿作用 沙坪沟钼矿 东秦岭-大别山
Abstract:The Shapinggou Mo deposit, located in Jinzhai Country of Anhui Province, is a giant ore deposit discovered in recent years in the Dabie Mountain. This paper describes geological characteristics of the ore deposit. The authors chose nine molybdenite-bearing samples for Re-Os isotopic dating, and the dating results show that the Re-Os model ages of the ore deposit are between (112.2±1.7) Ma and (113.9±1.7)Ma, and the calculated isochron age is (113.21±0.53) Ma, suggesting that molybdenum mineralization occurred in the late period of early Cretaceous. High-precision chronologic data of regional intrusions, Re-Os dating data of molybdenites and geotectonic location of Mo deposits indicate that there occurred 2 epochs comprising 4 stages of Mo mineralization during the Mesozoic period in East Qinling-Dabie Mountain region. These Mo ore-forming stages include 205~260 Ma of Indosinian period, and 148~138 Ma, 135~119 Ma and 116~105 Ma of Yanshanian period. The Mo mineralization during the late Yanshanian period is the strongest one and is also the major ore-forming period of Mo polymetallic ore deposits in East Qinling-Dabie Mountain region.
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基金项目:本文得到中央级公益性科研院所基本科研业务费专项资金(编号: K1022)、全国矿产资源潜力评价项目(编号: 1212010633901)、安徽省公益性地质科技项目秦岭-大别山造山带东段(安徽部分)钼金多金属成矿规律与找矿方向研究(编号: 2009-19)的联合资助
引用文本:
黄凡,王登红,陆三明,陈毓川,王波华,李超.2011.安徽省金寨县沙坪沟钼矿辉钼矿Re-Os年龄——兼论东秦岭-大别山中生代钼成矿作用期次划分[J].矿床地质,30(6):1039~1057黄凡,王登红,陆三明,陈毓川,王波华,李超.2011.Molybdenite Re-Os isotopic age of Shapinggou Mo deposit in Anhui Province and Mesozoic Mo ore-forming stages in East Qinling-Dabie Mountain region[J].Mineral Deposits30(6):1039~1057
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