摘要
本文初步分析研究了省内建阳水吉矿区风山林层控银铅锌矿的成矿机制及演化过程,总结了这一组热水沉积变质—岩浆气液叠加改造再造型层控矿床组合成因模式:在大陆雏形裂谷构造环境下经热水沉积形成银铅锌(硫)矿源层——上元古界龙北溪组中上段(Pt_(3/2+3))母含矿建造,深源铅模式年龄为946—814百万年;经区域变质期间“多”字型塑性流动褶皱作用,矿质二次迁移富集形成矿石铅模式年龄为695—483百万年的含矿层(A型);具“走滑转换构造”性质的燕山期控矿“S”形断裂构造,是导生含矿中基性脉岩(浆)热源体——生矿建造和决定矿质再次叠加改造成矿(B型)及再造成矿(C型)的关键。从中提出了“三造一体”的成矿富集机制。
This paper has a discussion on ore-formation mechanism and evolutary pattern of Fengshanlin Ag-Pb-Zn stratabound ore deposit, and summed up a genetic model for the stratabound deposits, which are of hydrothermal sedimention-metamorphie—magmatic pneumatohydatogenetic superimposed-reworked (and/or-recomposed) origin. Their evolutary process is as follow. In the embryonic continental rift stage, Ag-Pb-Zn (—S) source strata are formed by hydrothermal sedimentation. The strata are medium-upper menbers (Pt_(3/2+3)) of Longbeixi Formation of Upper Proterozoic Group and belong to primordial ore-bearing formation. Their deep lead model age is of 946—814Ma. Because of plastic flowage folding (ξ-type) in regional metamorphism, mineralised materials are migrated and concentrated. Then ore-bearing beds (A-type) are formed. Their lead model age is of 695—483 Ma. Yanshania ore-control fractures (S-type), showing features of strike-slip (transform) structures, are the structures as passageway for ore-bearing medium-basic magma and heat current. They make up ore-generating formation. Those structures are one of leading factores for ore-generating by superimposition-reworking (B-type) and superimposition-recomposition (C-type). Authors put forward 'three O' mechanism of ore-formation (primordial ore-bear ing formation, ore-generating formation and ore-control structure) and a mathematical geology model for the ore-hoursing structures of the Ag-Pb-Zn ore.
出处
《福建地质》
1990年第1期1-13,87,共13页
Geology of Fujian
