滇西上芒岗红色粘土型金矿常量元素地球化学

MAJOR ELEMEMT GEOCHEMISTRY OF SHANGMANGGANG RED CLAY-TYPE GOLD DEPOSIT IN THE WEST OF YUNNAN

滇西上芒岗红色粘土剖面中常量元素的垂向分布研究表明 ,K2 O、Fe2 O3 、Al2 O3 在剖面中的变化一致 ,呈双峰曲线变化 ,即在坡积带稍有富集、在残积带明显富集 ;而SiO2 与铁、铝等在剖面中的变化相反。红色粘土与矿区地层和矿化蚀变岩的常量元素对比分析表明了红色粘土可能来源于地层和矿化蚀变岩。常量元素之间的相关性以及常量元素与金的相关性分析表明K2 O、Fe2 O3 、Al2 O3 在红色粘土中为共生元素 ;金的富集主要受红色粘土中褐铁矿和伊利石的吸附影响。红土化参数分析说明了红色粘土剖面经历两次红土化作用 ,残积带相对于其它带经受过较强的红土化作用 ,但整个红色粘土剖面遭受的红土化作用不强 ,红土化程度低 ,仅处于粘土化阶段。

we analyzed the distribution of major elements in the red-clay profile. The results indicated K 2O varied in consistence with Fe 2O 3 and Al 2O 3 in red clay. Their contents are slightly high in the slopewash zone and distinctly high in the eluvial zone. SiO 2 varied in opposition to Fe 2O 3 and Al 2O 3. Differences in contents between major elements of red clay and those of strata and mineralized and altered rocks indicated the strata and mineralized and altered rocks were the sources of red clay. Correlations among major elements and between major elements and gold indicated K 2O, Fe 2O 3 and Al 2O 3 were coexisting oxides in red clay. The enrichment of Au mostly resulted with adsorption of illite and limonite in red clay. Lateritization parameters for the Shangmanggang red clay-type gold deposit indicated that the red-clay profile has experienced two phases of laterization.