摘要
本文对乌拉山金矿带铅同位素地球化学特征进行了研究,认为乌拉山金矿主要成矿物质来源于低μ值的下地壳.指明了乌拉山金矿带具有基底矿源岩、晚华力西期-早中生代花岗岩体、断裂构造多次活动三位一体的成矿地质条件.金矿床的形成至少要经过太古代(33亿年左右)火山沉积和晚华力西期-早中生代(2亿年左右)热液成矿两个阶段.
This paper deals with composition characteristics, tracing role and evolution history of Pb-isotope of wulashan gold ore belt. Gold ore deposits are genetically related to both of the metamorphic rocks and granites. Pb of the rocks in the ore belt is derived from the lower crust. Pb in ores is old multistaged normal lead characterized by lower crust Pb and orogenic belt Pb. Pb in granites consists of Pb from the lower crust, the upper crust and the orogenic belt. 33-36my is put forward first for the rock -forming age of wulashen Group. Pb-Pb method age of 280my represents a main regional metamorphism; the temporal growth model age of 235m, the maximum age of mineralization and a later heat event. Tracing role of Pb-isotope throws a new light on the Au-metallogeny of the Wulashan ore belt. Basement of Archean rocks make a basis on which Late Varisean-Middle Mesozoic granitic magmatism remobilized, transported and enriched gold. The related fractures make rooms for gold emplacement. Gold deposits in the belt experienced, at least, two stages i. e. volcano - sedimentary stage (330my) and Late Varisean-Middle Mesozoic granitic magmatism hydrothermal fluid stage (20my).
出处
《地质找矿论丛》
CAS
CSCD
1992年第1期93-102,共10页
Contributions to Geology and Mineral Resources Research
