The As-Contaminated Elqui River Basin: a Long Lasting Perspective (1975–1995) Covering the Initiation and Development of Au–Cu–As Mining in the High Andes of Northern Chile
The As-Contaminated Elqui River Basin: a Long Lasting Perspective (1975–1995) Covering the Initiation and Development of Au–Cu–As Mining in the High Andes of Northern Chile
复制标题
受砷污染的埃尔基河流域：一个长期的视角（1975-1995），涵盖了智利北部安第斯山脉高地金铜砷采矿的启动和发展
DOI：
10.1007/s10653-006-9045-1
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发表时间：
2006
影响因子：
4.2
通讯作者：
P. Higueras
中科院分区：
文献类型：
--
作者：
R. Oyarzun;S. Guevara;J. Oyarzún;J. Lillo;H. Maturana;P. Higueras
Elqui流域（智利北方）是一个高度污染的河流系统，砷含量比沃茨的平均含量高出三个数量级。造成这种污染的原因主要有三个方面：（1）区域地质和热液作用（2）晚期富砷铜矿的揭顶-侵蚀-氧化-淋滤过程，这一过程至少持续了1万年;最后但并非最不重要的是（3）从1970年代后期起在高海拔（海拔4000米以上）的金铜砷El印第奥矿的采矿活动。El印第奥矿物存款托管块状硫化物的大静脉，包括硫砷铜矿（Cu 3AsS 4）的重要存在。这些矿脉及其寄主岩石（也富含As和Cu）在全新世期间的持续自然侵蚀，导致重要和广泛的金属分散沿着河流系统。在所研究的采矿前时期（1975-1977年），高海拔的托罗河沃茨已经显示出非常高的砷浓度（0.36-0.52 mg l−1）。在El印第奥开始全面开采（1980年以后），导致这些值增加，1995年达到1.51 mg l−1 As的浓度。同年，该流域其他河流的砷浓度也达到峰值，分别为0.33 mg l − 1（Turbio）和0.11 mg l−1（Elqui）。这些数据大大超过了美国环保局对饮用水的规定（0.01 mg l−1 As），并且Elqui河中约10%的总As数据（以及Turbio河中的70%）高于智利灌溉水法律允许的最高水平（0.1 mg l−1 As）。
The Elqui watershed (northern Chile) constitutes a highly contaminated river system, with arsenic exceeding by up to three orders of magnitude the average for river waters. There are three main reasons that explain this contamination: (1) the regional geology and hydrothermal (mineralizing) processes that developed in this realm during Miocene time; (2) the later unroofing–erosion–oxidation–leaching of As–Cu rich sulfide ores, a process that have been taking place for at least 10,000 years; and last but not least (3) mining activities at the high-altitude (>4000 m above sea level) Au–Cu–As El Indio mine, from the late 1970s onwards. The El Indio mineral deposit hosted large veins of massive sulfides, including the important presence of enargite (Cu3AsS4). The continuous natural erosion of these veins and their host rocks (also rich in As and Cu) during Holocene time, led to important and widespread metal dispersion along the river system. During the studied pre mining period (1975–1977), the high altitude river Toro waters already showed very large As concentrations (0.36–0.52 mg l−1). The initiation of full scale mining at El Indio (1980 onwards) led to an increase of these values, reaching a concentration of 1.51 mg l−1 As in 1995. During the same year other rivers of the watershed reached peak As concentrations of 0.33 (Turbio) and 0.11 mg l−1 (Elqui). These figures largely exceed the USEPA regulations for drinking water (0.01 mg l−1 As), and about 10% of the total As data from the river Elqui (and 70% from the river Turbio) are above the maximum level allowed by the Chilean law for irrigation water (0.1 mg l−1 As).