Re–Os molybdenite dating of granite-related Sn–W–Mo mineralisation at Hnilec, Gemeric Superunit, Slovakia
Re–Os molybdenite dating of granite-related Sn–W–Mo mineralisation at Hnilec, Gemeric Superunit, Slovakia
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DOI：
10.1007/s00710-005-0082-8
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发表时间：
2005-04
影响因子：
1.8
通讯作者：
Milan Kohút;H. Stein
中科院分区：
文献类型：
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作者：
Milan Kohút;H. Stein
Hnilec花岗云英岩体外接触面的Re-Os橄榄岩年龄为斯洛伐克Gemeric超单元的锡、钨和橄榄岩矿化提供了时间限制。从Hnilec的Sn-W-Mo矿化的代表性样品中采集了两个辉橄榄岩分离物，其Re-Os年龄为262.2 ± 0.9和263.8 ± 0.8 Ma（2-sigma），两者非常吻合。获得的Re-Os辉长岩年龄与最近但精度较低的电子探针独居石年龄（276 ± 13 Ma）和来自Hnilec花岗岩侵入体的U-Pb单颗粒锆石年龄（250 ± 18 Ma）相似，支持Sn-W-Mo矿化的花岗岩相关云英岩成因。我们精确的Re-Os钙铝榴石年龄解决了关于宝石超单元高温矿化时间的长期争议。这些二叠纪年龄排除了阿尔卑斯山时代的建议。硫同位素组成δ 34 S（CDT）= 1.71 ± 0.2‰，与岩浆硫源一致。野外观测表明，在Hnilec花岗岩体附近缺乏广泛的接触晕。薄层花岗岩侵位在片状寄主岩石伴随着蚀变和形成的锡钨云英岩在花岗岩的上部和外接触钙铝榴石矿化，这两种通常缺乏在其他花岗岩体的Gemeric超单元。
Re–Os molybdenite ages from the exocontact of the Hnilec granite-greisen body provide temporal constraints for tin, tungsten and molybdenite mineralisation in the Gemeric Superunit, Slovakia. Two molybdenite separates were taken from a representative sample of the Sn–W–Mo mineralisation at Hnilec and their Re–Os ages of 262.2 ± 0.9 and 263.8 ± 0.8 Ma (2-sigma) are in excellent agreement. The obtained Re–Os molybdenite ages are similar to recent but less precise electron microprobe monazite (276 ± 13 Ma) and U–Pb single zircon (250 ± 18 Ma) ages from the Hnilec granite intrusion, supporting a granite-related greisen origin for the Sn–W–Mo mineralisation. Our precise Re–Os molybdenite ages resolve the long time controversy over the timing of high-temperature mineralisation in the Gemeric Superunit. These Permian ages eliminate suggestions of an Alpine age. The sulphur isotope composition of the studied molybdenite is δ34S(CDT)= 1.71 ± 0.2‰ and is consistent with a magmatic sulphur source. Field observations indicate the lack of a broad contact aureole in the vicinity of the Hnilec granite body. Shallow level granite emplacement in schistose host rocks was accompanied by alteration and formation of tin-tungsten greisen in the upper part of the granite and exocontact molybdenite mineralisation, both commonly lacking in other granite bodies within the Gemeric Superunit.