典型高温热泉中锑的形态分布及其地球化学成因  

The Morphological Distribution and Geochemical Genesis of Antimony in Typical High-Temperature Hot Springs

作　　者：宋泓禹 郭清海[1,2] Song Hongyu;Guo Qinghai(State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China;School of Environmental Studies,China University of Geosciences,Wuhan 430078,China)

机构地区：[1]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430078 [2]中国地质大学环境学院,湖北武汉430078

出　　处：《地球科学》2023年第3期946-957,共12页Earth Science

基　　金：国家自然科学基金项目(Nos.42077278,42111530023)。

摘　　要：锑为典型有害元素,地热成因锑是天然水环境中溶解态锑的重要来源,富锑热泉排泄的负面环境效应不容忽视.本文在藏南和滇西选择典型地热区,分析了热泉中锑的形态分布及其地球化学成因.总体上,研究区排泄的地热水具有远高于天然水环境背景值的锑含量,最高可达2128.7μg/L.水文地球化学计算表明热泉中锑的主要存在形态为锑酸盐和亚锑酸盐,但部分热泉样品中硫代锑占总锑百分比可高达35%.硫化物浓度、S(-Ⅱ)/Sb摩尔比,以及砷锑之间的竞争巯基化作用是影响热泉中硫代锑含量的关键因素.在本研究所涉及地热系统中,西藏玛旁雍错曲色涌巴、门士、莫落江为岩浆热源型地热系统,其地热水中锑源自高温条件下热储围岩淋滤和作为热源的岩浆房所释出流体的输入,西藏曲卓木、朗久与云南邦腊掌则属于非岩浆热源型地热系统,其热泉中的锑主要来源于地热水-围岩矿物相互作用.Antimony is a typical harmful element,and the negative environmental effects of antimony-rich hot springs discharge can not be neglected since geothermal genesis of antimony is an important source of antimony in the natural water environments.In this paper,the morphological distribution of antimony in hot springs and its geochemical genesis were analyzed in selected typical geothermal areas in southern Tibet and western Yunnan.In general,the antimony of geothermal water discharged from the study area can be up to 2128.7μg/L,which is much higher than the background values in the natural water environments.Hydrogeochemical calculations indicate that the main forms of antimony present in the hot springs are antimonate and antimonite,however,the percentage of thioantimony in some hot spring samples can be as high as 35%of the total antimony.Sulfide concentration,S(-II)/Sb molar ratio,and competitive thiolation between arsenic and antimony are the key factors affecting the content of thioantimony in hot springs.Among the geothermal systems involved in this study,the Tibetan MapamYumco,Moincer,and Moluojiang are magma-heat geothermal systems,and the antimony in the geothermal water originates from the input of fluids released from the hot storage surrounding rocks leaching and magma house as the heat source under high temperature conditions,while the Tibetan Quzuomu,Langjiu and Yunnan Banglazhang are non-magma-heat geothermal systems,and the main source of antimony in their thermal springs is geothermal water-peripheral rock mineral interaction.

关 键 词：热泉 锑 硫代锑 水-岩相互作用 岩浆流体输入 地球化学 

分 类 号：P641.3[天文地球—地质矿产勘探]