昆明理工大学翁强团队近日通过分析砷黄铁矿揭示了中国西南萨溪钨矿的氘成因。2025年5月15日出版的《地球化学学报》发表了这项成果。

萨西钨矿位于滇东南老君山矿区，是一个重要的钨多金属矿床。萨西矿床含钨伟晶岩脉和石英脉成矿成因尚不清楚。研究组利用蚀变花岗岩磷灰石原位U-Pb测年，结合毒砂微量元素和S-Pb同位素分析，探讨成矿流体的时间、强度和钨富集机制。蚀变花岗岩中磷灰石的U-Pb年龄为147.0±4.0 Ma，反映了早白垩世的岩浆活动。

研究组鉴定出3代毒砂（Apy），分别为蚀变花岗岩中的Apy-1、伟晶岩脉中的Apy-2和石英脉中的Apy-3。Apy-1、Apy-2和Apy-3的S/Fe比值分别为0.98 ~ 1.09、0.89 ~ 0.92和0.86 ~ 1.02（平均0.97），表明其岩浆-热液成因。硫同位素δ³⁴S = 4.29‰~ 8.11‰，表明其可能来自深部岩浆-热液流体。毒砂的铅同位素特征表明，其花岗质母岩浆来源于上部花岗岩。这些发现表明脉状钨矿的岩浆-热液成因与早白垩世隐伏的岩浆-热液系统有关。

附：英文原文

Title: Arsenopyrite reveals the deuteric origin of the Saxi tungsten deposit, SW China

Author: Li, Wanbo, Deng, Mingguo, Weng, Qiang, Li, Wenchang, Jia, Zhen, Song, Wenbo, Li, Zhengrong, Yang, Jiafei

Issue&Volume: 2025-05-15

Abstract: The Saxi tungsten deposit, located in the Laojunshan ore district of southeastern Yunnan Province, is a significant W-polymetallic deposit. The origins of tungsten-bearing pegmatite dikes and quartz vein mineralization in the Saxi deposit remain poorly understood. This study employs in situ U–Pb dating of apatite from the altered granite, along with trace element and S–Pb isotopic analysis of arsenopyrite, to investigate the timing, source of ore-forming fluids and the mechanisms of tungsten enrichment. The apatite in the altered granite yields a U–Pb age of 147.0±4.0 Ma, indicating magmatic activity during the Early Cretaceous. Three generations of arsenopyrite (Apy) are identified: Apy-1 in the altered granite, Apy-2 in the pegmatite dikes and Apy-3 in the quartz veins. The S/Fe ratios for Apy-1, Apy-2 and Apy-3 range from 0.98 to 1.09, 0.89 to 0.92 and 0.86 to 1.02, respectively (average 0.97), suggesting a magmatic-hydrothermal origin. Sulfur isotope values (δ34S=4.29‰–8.11‰) indicate that it was likely sourced from deep magmatic-hydrothermal fluids. Lead isotopic compositions of arsenopyrite suggest that the granitic parental magma is derived from the upper crust. These findings point to a magmatic-hydrothermal origin for the vein-type tungsten mineralization, linked to a concealed magmatic-hydrothermal system in the Early Cretaceous.

DOI: 10.1007/s11631-025-00777-8

Source: https://link.springer.com/article/10.1007/s11631-025-00777-8