摘要
通过我国古生代沉积型铝土矿含矿岩系的特征、形成条件分析，并与含金的红土型铝土矿含矿岩系进行对比，认为在我国古生代沉积型铝土矿合矿岩系下部铁质粘土岩中具找金的可能性，文中还分析了铝土矿形成过程中金的地球化学特征和富集方式。根据扫描电镜加能谱分析等，发现某些沉积铝土矿中的含金较高。
The sedimentary bauxite deposits in China are larger in scale. The formation of Carboniferous sedimentary bauxite lasted a long period(＞100Ma). In the early stage, the weathering anderosion were very strong with local erosion depth over 1000m. Ore reserve of carboniferous sedimentary bauxite makes up 72. 4% of the total of China; the reserve of Permian sedimentarybauxite, 16. 8% ; accumulation bauxite from Permian Sedimentary bauxite, 9 %. Ore-bearingstrata of Palaeozoic sedimentary bauxite often overly disconformably on carbonate rock; some onsandstone and shale ; Others grade into the underlying basic volcanic rock. The ore-bearing strataare often composed of (from bottom to top) ferriferous rock, bauxite, high-Al clay, clay, et al.The predominant minerals are diaspore (mainly transformed from gibbsite), hematite, kaolinite,goethite et al similiar to that of latentic gold ore-bearing strata in abroad, espeically for highercontents of Fe2O3 and clay minerals. However, the sequences are often reverse. The main metallogenitic conditions of palaeozoic sedimentary bauxite in China and latentic gold ore are similiar intectonic background, surface relief, weather, parent rock but the later was exposed to transportation and sedimentation. In this paper, the author analyses the geochemical characteristic ofgold in the course of bauxite formation, thinks it is possible that gold may enriches in the ferriferous clay of the lower part of the ore-bearing strata. In addition, some ore-bearing strata ofpalaeozoic sedimentary bauxite were apparently affected by structural, metamorphic, hydrothermal action, which migt cause the enrichment of gold. Higher contents of gold have been foundby SEM, EDX et al, in ore-bearing strata of Xiaoyi of Shanxi, Xiouwen of Guizhou, Nanchuanof Sichuan, Wenshan of Yunan. From the above, the author thinks it is possible to find gold orein the ore-bearing strata of palaeozoic sedimentary bauxite of China (especially in its lower partferriferous clay ).
出处
《地质找矿论丛》
CAS
CSCD
1997年第2期67-75,共9页
Contributions to Geology and Mineral Resources Research
关键词
铝土矿
含矿岩系
形成条件
金矿床
找矿
China
Palaeozoic bauxite
Ore-bearing strata
ore-finding possibility
