粤西上元古界—下古生界金背景值及其与金成矿的关系

GOLD BACKGROUND VALUES OF THE UPPER PROTE- ROZOIC-LOWER PALAEOZOIC AND THEIR RELATIONSHIPS TO GOLD MINERALIZATION IN WESTERN GUANGDONG PROVINCE

粤西地区90％以上的金矿床(点)都产于该区上元古界和下古生界变质地层中,但区内变质地层的金背景值及其与金矿化的关系一直没有系统的资料。笔者以1800个样品统计了上元古界和下古生界的金背景含量,并利用地层金含量的变化规律讨论了地层与金成矿的关系,认为区内大部分金矿床是变质岩(矿源岩)改造的产物。

More than 90% of gold deposits in western Guangdong Province occur in Upper Proterozoic and Lower Paleozoic metamorphic rocks, but there is no detailed information of the relationships between the gold content of metamorphic strata and gold mineralization. This paper presents the gold background values of the Upper Proterozoic and Lower Paleozoic obtained by analyzing more than 1800 samples. The gold average contents of the Upper Proterozoic, Cambrian, Ordovician and Silurian are 4. 02 × 10-9, 3. 71×10-9, 2. 68×10-9and 2. 95× 10-9, respectively. The gold variation and relationship between strata and gold mineralization are discussed. The great majority of the gold deposits in the district are the product of the reworking of metamorphic rocks (source rocks).