塔斯马尼亚大学Jonathan Cloutier小组宣布他们研制了地幔熔融及其伴生花岗岩类岩浆作用在劳伦山加里东构造造山带金成因中的作用。这一研究成果发表在2025年12月4日出版的国际学术期刊《地质学》上。

在这里，研究组以He同位素为主题，确定地幔热对驱动主要金矿床的成矿流体的贡献，这些金矿床位于英国和爱尔兰的Laurentian Caledonides，包括所有活跃的金矿（Cononish， Curraghinalt和Cavanacaw），其中许多被暂时归类为造山带。含金硫化物（0.093.3 R_a）流体的³He/⁴He需要大量的岩浆挥发物的贡献，这表明地幔热是成矿的内在因素。最大的矿床Curraghinalt是在格兰pian事件期间由岩浆He比例最高的最热矿石流体形成的。较小的晚加里东期沉积来自较低³He/⁴He的较冷流体。矿液³He/⁴He与硫化物δ³⁴S（- 1.9 ~ 9.1‰）不相关，反映了多成因S的存在。最大³He/⁴He与Au储量呈正相关关系，说明黄金是由加里东造山运动后俯冲作用产生的基性地幔熔体中提取的。

研究人员表示，造山金脉矿床是一种经济上重要的、文献翔实的矿化类型，但关于其成因中岩浆作用的共识有限。

附：英文原文

Title: The role of mantle melting and associated granitoid magmatism in the genesis of orogenic gold in the Laurentian Caledonides

Author: Calum M. Lyell, Finlay M. Stuart, James I. Shaw, Adrian J. Boyce, Jonathan Cloutier

Issue&Volume: 2025-12-04

Abstract: Orogenic gold vein deposits are an economically important, well-documented mineralization class with limited consensus regarding the role of juvenile magmatism in their genesis. Here we use He isotopes to determine the contribution of mantle heat in driving the ore fluids responsible for major gold deposits in the Laurentian Caledonides of Britain and Ireland, including all active mines (Cononish, Curraghinalt, and Cavanacaw), many of which are tentatively classed as orogenic. The 3He/4He of fluids in Au-bearing sulfides (0.093.3 Ra) require a significant contribution from exsolved magmatic volatiles, implying that mantle heat is intrinsic to ore formation. The largest deposit, Curraghinalt, formed from the hottest ore fluids with the highest proportion of magmatic He during the Grampian Event. The smaller late-Caledonian deposits precipitated from cooler fluids with lower 3He/4He. Ore-fluid 3He/4He does not correlate with sulfide δ34S (1.99.1‰) reflecting multiple crustal S sources. A positive correlation between the maximum 3He/4He and Au reserve implies that gold was sourced from mafic mantle melts generated by post-subduction processes during the Caledonian orogeny.

DOI: 10.1130/G54161.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G54161.1/721721/The-role-of-mantle-melting-and-associatedredirectedFrom=fulltext