Cassiterite U-Pb age, fluid inclusion and H-O-S-Pb isotope geochemistry of the Xiaogushan Sn-Zn deposit in the southern Great Xing'an Range, NE China
Year: 2023
Type: article
Abstract: 毛登-小孤山地区是大兴安岭南段锡多金属成矿带代表性矿区, 由小孤山锡锌矿床和毛登锡钼铋多金属矿床组成。小孤山矿床锡石U-Pb Tera-Wasserburg谐和年龄为134.8±1.9Ma, 表明其形成于早白垩世。该矿床成矿过程可划分为4个阶段: 锡石-黄铁矿-石英-电气石阶段(Ⅰ阶段)、锡石-黄铜矿-闪锌矿-石英-萤石阶段(Ⅱ阶段)、闪锌矿-方铅矿-石英-萤石阶段(Ⅲ阶段)、黄铁矿-石英-方解石阶段(Ⅳ阶段)。小孤山矿床主要发育富液两相包裹体(WL型)、富气两相包裹体(WG型)及含子矿物包裹体(S型)。Ⅰ、Ⅱ和Ⅲ阶段均发育WL、WG和S型包裹体, Ⅳ阶段仅出现WL型包裹体。从Ⅰ至Ⅳ阶段流体包裹体均一温度/盐度分别为420~443℃/8.3%~52.0% NaCleqv、286~379℃/4.0%~40.2% NaCleqv、214~299℃/3.8%~36.1% NaCleqv、178~195℃/2.1%~3.3% NaCleqv, 表明从早阶段到晚阶段成矿流体由高温高盐度向低温低盐度转化, 且前三个阶段流体盐度波动大, 暗示成矿流体发生了多次沸腾。矿床的δ18O水介于-2.6‰~11.0‰, δD介于-107‰~-91‰, Ⅰ和Ⅱ阶段的成矿流体以岩浆水为主, Ⅲ阶段开始有大气降水的加入。硫化物的δ34SCDT值介于-3.3‰~-0.6‰, 206Pb/204Pb介于17.772~18.427, 207Pb/204Pb介于15.482~15.679, 208Pb/204Pb介于37.668~38.622, 表明成矿物质来源于早白垩世花岗质岩浆。流体沸腾和降温是矿质沉淀的两种主要机制。
Source: Acta Petrologica Sinica
Authors: Guang WU, Fei YANG, RuiHua LI, GongZheng CHEN, Tong ZHANG, JiangPeng SHI, ShiHui LI
Language: English
Subfield: Economics and Econometrics
Domain: Social Sciences
Open Access status: hybrid
OpenAlex ID: W4380153189