瑞士伯尔尼大学Pierre Lanari小组取得一项新突破。他们报道了西阿尔卑斯山新生代PbZnAg的成矿作用。2024年2月16日出版的《地质学》发表了这项成果。

研究人员将岩石学与RbSr和UThPb原位年代学相结合，在薄片尺度上配对，确定了法国西阿尔卑斯山东西向样带变形热液PbZnAg矿床的成矿时间。矿石主要由方铅矿在石英-云母脉石中组成。这种共生可能与变应变期间的水热结晶有关。

这两种同位素体系都只能得出新生代的年龄，没有任何前阿尔卑斯遗传，表明了造山带成矿作用。本文提出的成矿模式包括在阿尔卑斯辐合过程中，沿基底与盖层之间主要构造接触的流体循环。

附：英文原文

Title: Cenozoic PbZnAg mineralization in the Western Alps

Author: Maxime Bertauts, Adrien Vezinet, Emilie Janots, Magali Rossi, Isabelle Duhamel-Achin, Philippe Lach, Pierre Lanari

Issue&Volume: 2024-02-16

Abstract: Metallogenic models of polyphase mountain belts critically rely on robust geochronology. We combine petrology with RbSr and UThPb in situ geochronology, paired at thin-section scale, to date mineralization in deformed hydrothermal PbZnAg deposits along an east-west transect in the Western Alps, France. The PbZnAg veins occur in shear zones with kinematic structures consistent with the mylonitized host rocks. The ore consists mainly of galena in a quartz-phengite gangue. The paragenesis can be related to hydrothermal crystallization during periods of variable strain. Both isotope systems yield only Cenozoic ages (ca. 35 Ma and 1520 Ma) without any pre-Alpine inheritance, clearly indicating orogenic mineralization. The metallogenic model proposed here includes significant fluid circulation along major tectonic contacts between basement and sedimentary cover during Alpine convergence.

DOI: 10.1130/G51818.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51818.1/634923/Cenozoic-Pb-Zn-Ag-mineralization-in-the-WesternredirectedFrom=fulltext