中朝准地台原生金矿铅同位素特征及有关问题的讨论

本文研究了中朝准地台原生金矿床各类地质体铅同位素组成特征,认为中朝准地台构造环境的演化趋势是从活动带到稳定克拉通又到活化克拉通;与此同时,由于构造环境的缘故,金的演化历史主要分为两个阶段:一是金矿源层的形成(37～20亿年),二是金的活化与成矿作用(1.8～1.0亿年);并初次确立了在准地台上寻找同类金矿床的地质、地球化学找矿模式,即:太古代变质岩系(金源)—中生代花岗岩浆作用(金的活化、转移、富集)—含金构造裂隙(金的集中、沉淀、成矿)。

DISCUSSION ON CHARACTERISTIC OF LEAD ISOTOPE COMPOSITION OF ORIGINAL GOLD DEPOSITS IN SINO-KOREAN PARAPLATFORM AND RELATION TO SOME PROBLEMS

This paper deals with the characteristics of lead isotope composition of gold deposits in the Sino-Korean paraplatform.The author has drawn the following conclusion. The tectonic evolutionary tendency of the Sino-Korean paraplatform is from mobile belt to stable craton, and to rejuvenated craton again. At the same time, in consequence of the tectonic evolution, the evolutionary history of gold deposits may be divided into two stages. The first stage is formation of the gold source bed (3.7-2.0 b. y. ), and the second stage is the glod remobilization and mineralization (0.18 - 0.1 b. y. ) The geologic-geochemical model is set up first for exploration of gold deposits in the Sino-Korean paraplatform in this paper, i. e. Archean metamorphic rock series(source bed of gold)-Mesozoic acid magmatic activity (mobilization, migration, enrichment)-ore-bearing fracture zone (concentration, precipitation, ore forming).