近日,中国科学院地球化学研究所张正伟团队研究了阿克塔什VMS矿床的汞同位素地球化学:成矿流体来源的约束。该研究于2025年8月27日发表在《地球化学学报》杂志上。
研究组对西昆仑造山带竹桥火山块状硫化物(VMS)矿床中黄铁矿的汞(Hg)同位素地球化学特征进行了研究,旨在阐明成矿流体强度和成矿过程中汞同位素的特征。赤石矿床位于晚古生代弧后盆地内,具有广泛的石炭纪岩浆活动和热液活动特征。
19个黄铁矿样品的Hg同位素组成δ202Hg值在- 2.48‰~ 0.87‰之间,Δ199Hg值在- 0.02‰~ 0.40‰之间。负的δ202Hg值表示热液作用导致的同位素分馏,而正的Δ199Hg值表示岩浆和海水混合流体的存在。研究组强调了汞同位素在VMS系统中追踪多流体相互作用(如岩浆与海水)方面的独特优势,为全球成矿研究提供了一种新的方法。他们的发现不仅解决了长期以来关于阿克塔什流体成因的争论,而且为将汞同位素应用于世界其他VMS矿床建立了框架。
附:英文原文
Title: Mercury isotope geochemistry of the Aketashi VMS deposit: Constraints on ore-forming fluid sources
Author: Jin, Ziru, Zhang, Zhengwei, Wu, Chengquan, Xu, Jinhong, Li, Xiyao
Issue&Volume: 2025-08-27
Abstract: This study investigates the mercury (Hg) isotope geochemistry of pyrite from the Aketashi volcanic hosted massive sulfide (VMS) deposit in the West Kunlun Orogenic Belt, China, aiming to elucidate the sources of ore-forming fluids and the behavior of Hg isotopes during mineralization. The Aketashi deposit is located within a Late Paleozoic back-arc basin, which is characterized by extensive Carboniferous magmatism and hydrothermal activity. Analysis of 19 pyrite ore samples revealed Hg isotope composition with δ202Hg values ranging from 2.48‰ to 0.87‰ and Δ199Hg values from 0.02‰ to 0.40‰. The negative δ202Hg values are indicative of isotopic fractionation resulting from hydrothermal processes, whereas the positive Δ199Hg values imply a mixed fluid source comprising both magmatic and seawater-derived components. This study highlights the unique advantage of Hg isotopes in tracing multi-source fluid interactions (e.g., magmatic vs. seawater-derived) in VMS systems, providing a novel methodology for global metallogenic studies. Our findings not only resolve the long-standing debate on fluid origins at Aketashi but also establish a framework for applying Hg isotopes to other VMS deposits worldwide.
DOI: 10.1007/s11631-025-00814-6
Source: https://link.springer.com/article/10.1007/s11631-025-00814-6
Acta Geochimica:《地球化学学报》,创刊于1982年。隶属于施普林格·自然出版集团,最新IF:1.6
官方网址:https://link.springer.com/journal/11631
投稿链接:https://www2.cloud.editorialmanager.com/cjog/default2.aspx