当前位置:科学网首页 > 小柯机器人 >详情
用钼同位素示踪斑岩型钼矿源区的黑色页岩
作者:小柯机器人 发布时间:2023/5/25 10:45:56

中国科学院海洋研究所Weidong Sun等提出了一种用钼同位素示踪斑岩型钼矿源区的黑色页岩的方法。相关论文于2023年5月19日发表在《地质学》杂志上。

课题组研究人员提供了冈底斯成矿带邦普斑岩型钼(铜)矿床,中新世矿化二长花岗岩(MPMs)和古新世贫黑云母二长花岗岩及凝灰岩(BMTs)的钼同位素数据。研究表明,MPMs显示,放射性锶、铅同位素和高δ98/95Mo(相对于NIST SRM 3134; + 0.07‰-1.2‰)和Mo含量,超过了亏损地幔的范围。正如δ98/95Mo和εNd(t)和铝饱和指数(ASI)值之间的显著相关性所证明的那样,这些特征不能归因于表面风化、热液蚀变、岩浆分异或部分熔融,而是反映了黑色页岩中的钼进入了其岩浆源。

相比之下,BMTs的钼和δ98/95Mo值低于矿化样品,δ98/95Mo值与放射性同位素或ASI值没有相关性。而且。矿化和贫瘠的样本的对比特征提供了强有力的证据,表明黑色页岩的加入在邦普斑岩型钼矿床的形成中起了重要作用。因此,此项研究建立了斑岩型钼矿床与富有机质沉积物之间可能的联系,并强调了钼同位素在斑岩型钼矿床研究中的巨大潜力。

据悉,斑岩型钼矿床是工业用钼的重要来源,但这些矿床中金属的来源仍有争议。

附:英文原文

Title: Tracing black shales in the source of a porphyry Mo deposit using molybdenum isotopes

Author: Qiqi Xue, Lipeng Zhang, Shuo Chen, Kun Guo, Tao Li, Zhong Han, Weidong Sun

Issue&Volume: 2023-05-19

Abstract: Porphyry Mo deposits are important suppliers of molybdenum for industrial applications, but the origin and source of metals in these deposits remain debated. Here, we present Mo isotope data for Miocene mineralized porphyritic monzogranites (MPMs) and Paleocene barren biotite monzogranites and tuffs (BMTs) from the Bangpu porphyry Mo (Cu) deposit in the Gangdese metallogenic belt. The results show that the MPMs display radiogenic Sr and Pb isotopes and elevated δ98/95Mo (relative to NIST SRM 3134; +0.07‰–1.2‰) and Mo contents, which exceed the range of the depleted mantle. These characteristics cannot be attributed to surface weathering, hydrothermal alteration, magmatic differentiation, or partial melting but rather reflect the incorporation of Mo from black shales into their magma sources, as evidenced by the significant correlations between δ98/95Mo and εNd(t) and aluminum saturation index (ASI) values. In contrast, the BMTs display lower Mo and δ98/95Mo values than the mineralized samples, and their δ98/95Mo values display no correlations with radiogenic isotopes or ASI values. The contrasting characteristics of mineralized and barren samples provide strong evidence that the addition of black shales played an important role in the formation of the Bangpu porphyry Mo deposit. Our study thus establishes a possible link between porphyry Mo deposits and organic-rich sediments and highlights the great potential of Mo isotopes in studying porphyry Mo deposits.

DOI: 10.1130/G51240.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51240.1/623575/Tracing-black-shales-in-the-source-of-a-porphyryredirectedFrom=fulltext

期刊信息

Geology:《地质学》,创刊于1973年。隶属于美国地质学会,最新IF:6.324
官方网址:https://pubs.geoscienceworld.org/geology
投稿链接:https://geology.msubmit.net/cgi-bin/main.plex