全球锑矿床成矿学基本特征及超大型锑矿床成矿背景初探

本文对全球锑成矿的基本特征进行了初步研究并编制了全球锑成矿图。研究表明全球锑成矿的一般规律具以下特点：锑成矿与大陆型壳体的构造发展阶段及演化程度具显著相关性，全球锑矿床可划分为地槽型（或古地槽型）和地洼型两种基本大地构造类型；锑成矿在时、空分布上具有不均一性，成矿主要集中于大陆壳体较晚地质历史（中、新生代）的地槽区和地洼区；锑成矿是地洼区特征性成矿之一，往往在分异，演化程度较高的地洼区内形成锑成矿高峰；沿与深部上地幔关系密切的浅部碎裂岩断层带以中─低温热液交代或充填的方式富集是地洼型锑成矿的基本型式。最后文中对超大型锑成矿富集特殊性与非超大型锑工业富集的一般性进行了对比研究。

CHARACTERISTICS OF GLOBAL ANTIMONY METALLOGENY AND PRELIMINARY STUDY ON GEOLOGICAL BACKGROUND OF THE SUPERLARGE ANTIMONY MINERALIZATION

In the article,the characteristics of global antimony metallogeny have been studied. The researehes on the tectonochemical properties of Sb element,distribution of antimony deposits in space─time and the differences between the superlarge and crustobodies.The migration and enrichment of Sb element were controlled by the evolution of the Earth. Sb element belongs to the centrifugal elements and possesses geotectonic differentiation and fracture─affinity properties. With the increase of crustobodies' maturity, Sb element tended to move from the interior of crustobodies and to be enriched in the shallow fracture zones of the upper crust.Antimony metallogeny is characterized by discontinuous distribution in space─time. Antimony deposits mainly occurred in the continental crustobodies, especially in those in the circum─Paciflc(East Asia,South America and North America).Antimony mineralization usually took place within the activation belts(geosynclinal or geodepression (diwa) regions)of the crustobodies in the Mesozoic and Cenozoic.According to the tetonic settings of mineralization,antimony deposits can be divided into two types:geosynclinal and diwa type.Diwa type antimony deposits,located in the regions with the highest maturity,are the most important antimony resources because they make up the majority of the world antimony reserves. They are mostly epithermal deposits occurring in brittle fracture zones.Comparing the Xikuangskan superlarge antimony deposit with non─superlarge ones,we can find out that the superlarge antimony deposit was the product of multi─stage antimony mineralization.From the Early Proterozoic to the Early Paleozoic,the Central Hunan, where the Xikuangshan antimony deposit occurred, was at geosynclinal stage.Geosynclina] type antimony mineralization took place in this area and numerous small antimony deposits and ore spots were formed.Aftar a short platform stage(Pz2─T2),this area entered geodepression(diwa)stage.Sb element,primarilly enriched in the geosynclinal structural layers, was remobilized by the intense tectono─magmatic activities and transporteil by hydrothennal solution. In favorable environment the abundant ore─forming metal was precipated to form the superlarge antimony deposit.