分散元素超常富集的资源与环境效应:研究现状与发展趋势

Resources and environmental effects of abnormal enrichment of dispersed elements: research situation and tendency

传统观点认为,Cd,Ga,In,Tl,Ge,Se,Te,Re等分散元素不能形成独立矿床,它们只能以伴生元素的方式存在于其他元素的矿床内。近年来,中国西南地区多例分散元素独立矿床的相继发现,打破了这一传统的思维方式和科学理念。在对国内外分散元素矿床研究现状和存在问题分析的基础上,提出扬子地块西部大陆边缘构造演化及其所控制的壳幔置换、流体活动、元素分馏等动力学过程,控制了区域内分散金属成矿作用的基本样式和矿床时空分布的基本格局。未来对分散元素超常富集机理及资源与环境效应研究,应着重于三方面,即:分散元素矿集区的成矿大陆动力学背景、分散元素成矿作用的共性和差异性及与其他矿化元素共生-分异的化学动力学机制、表生循环过程中分散元素的地球化学行为及其对生态和环境的制约。

Dispersed elements, including Cd, Ga, In, Tl, Ge, Se, Te and Re, are traditionally considered to be impossible to form independent ore deposits. However, the discovery of a number of independent ore deposits of dispersed elements in western China in the recent years has broken this traditional cognition. Based on the analysis of current research situation and existing problems in the study of dispersed element deposits, the authors of this paper propose that the tectonic evolution and associated crust-mantle (replacement), fluid activity, and geochemical fractionation processes of the western margin of the Yangtze block have controlled the principal styles of mineralization and distribution framework of dispersed element deposits. Future research on the mechanism of abnormal enrichment of dispersed elements and its resources and environmental effects should be focused on three main aspects, i.e., the metallogenic geodynamics of enrichment districts of dispersed elements, the generality and discrepancy in mineralization of dispersed (elements) and chemical dynamics of their intergrowth and/or separation with other mineralizing elements, and the geochemical behaviors of dispersed elements during supergene circulation and their constraints on (ecological) and environmental systems.