摘要
本文对５７０矿床新鲜岩石、蚀变岩石的稀土元素进行了地球化学研究。稀土元素特征表明，矿区基底花岗岩的成因类似华南改造型花岗岩；火山岩可能是基底变质深熔作用形成；次花岗斑岩与火山岩同源。在弱酸性－中性热液蚀变（赤铁矿化和水云母化）过程中，稀土元素的变化不大，仅表现为稀土总量有所增减；而碱性蚀变（碱交代和碳酸盐化）则一方面表现出稀土总量的变化，另一方面轻、重稀土的分馏程度也有变化。矿石中稀土总量，特别是重稀土含量普遍升高，这一特征可以作为铀成矿的指示标志。
The No. 570 ore deposit is a volcanic type uranium, silver and molybde-num deposit.In this paper,REE geochemical studies of this deposit have been made in such aspects as basement rocks,surrounding rocks,altered rocks and ores. The surrounding volcanic rocks aro enriched in REE(ΣREE=407.7 ×10￣(-6))and strongly depleted in Eu(δEu=0.05 ), and their REE patterns declinerightward,These characteristics are quite simular to REE features of base-ment migmatite,suggesting that these volcanic rocks might have been formed through the anatexis of basement rocks, The basement granite is characte-rized by enrichment of LREE,obvious fractionation between LREE and HREE(LREE/HREE=7.51～9.97)and evident depletion of Eu(δEu=0.45～0.47),rather similar to REE characteristics of the transformation type uraniferousbiotite granites In South China. This implies that the basoment granite is probably a product of crustal remelting and transformation. In alkaline alte-ration(carbonation and alkali metasomatism),there is enrichment or depletionof REE, whereas in hydromicatization and red alteration REE are relativelystable. The totaI REE content of ore, especially the HREE content,is appa-rently higher than barren rocks.The precipitation and enrichment of ura-nium are accompanied by the enrichment of ΣREE, especially HREE,Such be-haviors of REE might indicate uranium mineralization.
出处
《矿床地质》
CAS
CSCD
北大核心
1995年第1期35-43,共9页
Mineral Deposits
关键词
地球化学
稀土族
蚀变岩
稀土元素矿床
rare earth elements, geochemical evolution,No. 570 ore depoist
