A reinterpretation of the mineralisation processes involved in the formation of the Tomnadashan sulphide deposit, Loch Tay, Scotland, UK
A reinterpretation of the mineralisation processes involved in the formation of the Tomnadashan sulphide deposit, Loch Tay, Scotland, UK
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英国苏格兰泰湖 Tomnadashan 硫化物矿床形成过程中的矿化过程的重新解释
DOI：
10.1144/sjg2023-023
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发表时间：
2024
影响因子：
0.7
通讯作者：
Webb S
中科院分区：
文献类型：
--
作者：
Webb S
Tomnadashan硫化物矿床位于Loch Tay（苏格兰，英国）的南缘，是在19世纪开采铜的。对Tomnadashan的成因过程仍然知之甚少，而且矿化也从未确定过年代。为了更好地了解这一矿物系统，我们使用Re-Os计时器对Tomnadashan的辉钼矿进行了测年。此外，我们将这些年龄置于共生解释的背景中。结果表明，辉钼矿的年龄基本一致。423-419 Ma，发生在共生早期（六期中的第二期）。根据辉钼矿的共生作用，该年龄可能反映了台湖加里东期初始成矿事件。我们的新资料和文献综述表明，虽然Tomnadashan是一个与岩浆有关的矿床，但出露的斑岩不太可能提供与成矿相关的成矿流体。斑岩内隐伏的侵入体或花岗岩脉可能是岩浆热液流体的来源。年龄资料表明，Tomnadashan成矿作用与北爱尔兰Cavanacaw金矿成矿作用处于同一时期，表明在格兰pian地体可能存在一个以前未被认识到的中志留统岩浆-热液期的金和贱金属成矿作用。主题收集：本文是早期职业研究收集的一部分：https://www.lyellcollection.org/topic/collections/early-career-research
The Tomnadashan sulfide deposit, which is located on the southern margin of Loch Tay (Scotland, UK), was mined for copper during the 19th century. The genetic processes at Tomnadashan remain poorly understood, and the mineralization has never been dated. To gain an improved understanding of this mineral system, we have dated the molybdenite at Tomnadashan using the Re–Os chronometer. Furthermore, we have contextualized these ages within a paragenetic interpretation. Our results show that the age of the molybdenite isc.423–419 Ma, and it occurs early in the paragenesis (the second stage out of six). Based on the paragenesis of molybdenite, this age is likely to reflect the initial Caledonian mineralization event at Loch Tay. Our new data and literature review suggest that although Tomnadashan is a magmatic-related ore deposit, the porphyry that crops out is unlikely to have provided the mineralizing fluids associated with the mineralization. A concealed intrusion or granitic dykes within the porphyry may be the source of the magmatic–hydrothermal fluids. The age data indicate that the Tomnadashan mineralization is coeval with gold mineralization at Cavanacaw in Northern Ireland, giving rise to the possibility of a previously unrecognized mid-Silurian magmatic–hydrothermal episode of gold and base metal mineralization throughout the Grampian Terrane.Thematic collection:This article is part of the Early Career Research collection available at: https://www.lyellcollection.org/topic/collections/early-career-research