陈钧渝,沈鸿杰,颜伟裕.中天山狼牙泉铅锌矿床闪锌矿LA-ICP-MS微量元素特征对矿床成因的指示意义[J].矿产勘查,2023,14(3):377-391 |
中天山狼牙泉铅锌矿床闪锌矿LA-ICP-MS微量元素特征对矿床成因的指示意义 |
LA-ICP-MS trace element geochemistry of sphalerite: Metallogenic constraints on the Langyaquan Pb-Zn deposit in the Middle Tianshan metallogenic belt |
投稿时间:2022-07-01 |
DOI:10.20008/j.kckc.202303005 |
中文关键词: 闪锌矿 微量元素 狼牙泉铅锌矿床 LA-ICP-MS 矽卡岩型矿床 |
英文关键词: sphalerite trace element Langyaquan Pb-Zn deposit LA-ICP-MS skarn-type lead-zinc deposit |
基金项目:本文受湖南省科技创新计划 (2021RC4055) 资助。 |
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中文摘要: |
中天山铅锌成矿带东部地块位于中亚造山带南缘,铅锌金银成矿条件优越,狼牙泉铅锌矿床是该区近年来找矿勘查所发现的重要的铅锌多金属矿床之一。本文采用激光剥蚀电感耦合等离子质谱仪(LA-ICP-MS)对该矿床闪锌矿开展了原位微区微量元素分析,分析结果表明:闪锌矿以富集Fe、Cd、Mn、Co和In而亏损Ga、Cu、Ag、Sn和Pb为特征。其中Fe、Cd、Mn、Co和In等元素以类质同象形式存在,而Cu、Pb、Sb和Ag则以类质同象和包裹体形式赋存。根据不同微量元素间的相关关系,认为闪锌矿中存在Fe2+(Cd2+/Mn2+) Zn2+、In3++Cu+ 2Zn2+、Ga3++In3+ 3Zn2+和Sb3++Ag+ 2Zn2+等简单和复杂替代关系。此外,闪锌矿In/Ga比值(155.7~656.7)较高,暗示其较高的形成温度。闪锌矿的微量元素组成以及Cd/Fe-Co、Cd/Fe-Mn、Cu-Sn以及Mn-In相关性图解均显示其与矽卡岩型铅锌矿床中的闪锌矿类似,明显有别于MVT、SEDEX、VMS等类型的铅锌矿床。此外,该矿床的形成与华里西期构造岩浆活动有关,矿体主要呈脉状和透镜状产出,矿物共生组合比较复杂(闪锌矿、方铅矿、黄铁矿、毒砂、黄铜矿和磁黄铁矿),铅和锌的品位偏低(<4%),矿床的形成温度为中低温,可见典型的矽卡岩化蚀变,上述特征表明狼牙泉铅锌矿床属于矽卡岩型铅锌矿床。 |
英文摘要: |
The eastern block of the Middle Tianshan Pb-Zn metallogenic belt characterized by superior Pb-Zn-Au-Ag metallogenic conditions is an important part of the Central Asian Orogen. The Langyaquan deposit is one of the representative Pb-Zn polymetallic deposits discovered in recent years. In this paper, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to analyze the trace elemental composition of sphalerite. The results show that sphalerite was enriched in Fe-Cd-Mn-Co-In but depleted in Ga-Cu-Ag-Sn-Pb. Iron, Cd, Mn, Co, and In elements occur as solid solution, while other elements, notably Cu, Pb, Sb, and Ag are distributed as both solid solution and inclusions. Based on the correlation of different trace elements, we discovered some important coupled substitutions:Fe2+ (Cd2+/Mn2+) Zn2+, In3++Cu+ 2Zn2+, Ga3++In3+ 3Zn2+ and Sb3++Ag+ 2Zn2+. Moreover, the In/Ga ratio of the Langyaquan sphalerite is high (155.7~656.7) indicating a high formation temperature. The Langyaquan sphalerite is generally featured by depletions in Fe-In-Sn, and enrichments in Mn-Co, resembling skarn-type sphalerite. Meanwhile, evidence from the Cd/Fe-Co, Cd/Fe-Mn, Cu-Sn, and Mn-In deposit-type discrimination plots imply that the Lanyaquan sphalerite plots in the skarn-type field, are consistent with the typical geological feature of skarn-type Pb-Zn deposit, with veined-shaped orebodies, low grade of Zn and Pb, commonly lower than 4%, complicated metallic mineral assemblage consisting of sphalerite, galena, pyrite, arsenopyrite, chalcopyrite, and pyrrhotite, and representative hydrothermal alteration of skarn. |
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