摘要
本文通过对建瓯群变质岩和上侏罗统火山岩中金的丰度、活度的分析对比和对分散流异常的削析,并借助于汞的热释谱测定、数理统计等方法,对分散流异常的异常源、矿化蚀变带,进行了含矿性评价。认为在建瓯群变质岩区。不易形成混合岩化-重熔岩浆热液型、变质热液型金矿。在闽东-闽东南上侏罗统火山岩分布区不具备火山及次火山-热液型金矿的成矿条件。
The Jian'ou Group metamorphic terrane in northern Fujian and the Upper Jurassic volcanic terrane in eastern and southeastern Fujian are often considered as metallogentic prospect areas of migmatization-anatectic magmatic hydrothermal type, metamorphic-hydrothermal type and volcanic and subvolcanic-hydrothermal type gold ore deposits.1. The gold abundance of the Jian'ou Group is 4.4 ppb (AnZl) and 3.58 ppb (AnZd), only corresponding with the Clarke value (4 ppb, Taylor, 1964), but it is greatly lower than that in the known source bed——the Jiandong Group and Chencai Group. 2. The migmatization of the known source beds (e. g. the Jiaodong Group) was strong, more titan 2/3 of the gold was remobilized during the prooesss of migmatization; on the other hand, the migmatization of the Jian'ou Group Was weaker and the concentration of gold was not notable around migmatitization. 3. The gold abutdance in Upper Jurassic volcanic rocks is very low, being only 1.29 ppb (J_3c) and 1.63 ppb (J_3n), while the gold abundance in the Upper Jurassic Jingoulin Formation volcanic and subvoicanic rocks of the Wufeng gold deposit in Jilin is 20 ppb and 22 ppb. 4. The evaluation of the gold potentiatity of the mineralized-altered belts causing dispersion flow anomalies shows that: (1) the thermal releaase spectra of mercury belong to the barren type, (2) minerralizedaltered belts have no element assemblage or correlation of gold ore in the known volcanic terrane, and (3) the pyritization-siliofioation belts in eastern Fujian is only related to mineralized hydrothermal fluids which contain less gold and the Dalinshan anomaly along Huian-Xianyou is mainly caused by iron-manganese mineralization. 5. Some high gold cooncentration has a bearing on supergene residual concentrtion.Therefore the author concludes that in the metamorphic terrane of the Jian'ou Group and the Upper Jurassic volcanic terrane in eastern and southeastern Fujian there exists sporadical fold mineralization due to original inhomogeneous distribution of elements and hydrothermal alteration, but there seem not exist gold deposits of migmatized-anatectic magmatic hydrothermal type and volcanic and subvolcanic-hydrothermal type.
出处
《地质论评》
CAS
CSCD
北大核心
1989年第6期521-528,共8页
Geological Review
