Abstract

A comparative analysis of the composition and structure of the surface facies of carbonatite weathering crusts (profiles) in the Chuktukon (Russia) and Seis Lagos (Brazil) deposits and ultra-rich rare metal ores in the Tomtor deposit (Russia) is presented. It is shown that the main geochemical trends in the formation of the Tomtor-type ultra-rich rare metal ores and the surface facies of weathering profiles are opposite. The obtained results do not confirm the genetic link between the unique Tomtor ores and the surface facies of the crust of carbonatites, but serve as evidence of their later formation due to the reductive epigenesis of carbonatite weathering products under the influence of solutions draining the overlying coaliferous rocks. Wide distribution of the phenomena of colloidal liquid layering into manganese and ferruginous fractions was established for the first time in surface facies of the weathering crust of carbonatites, and active lateral colloidal migration of Ti from the host rocks was revealed.

中文翻译：

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碳酸岩风化壳中的表面地层：对俄罗斯 Tomtor 矿床独特稀有金属矿成因的启示

摘要

对比分析了楚克图孔（俄罗斯）和塞斯拉各斯（巴西）矿床中碳酸岩风化壳（剖面）与托姆托尔矿床（俄罗斯）中超富稀有金属矿的表面相组成和结构。结果表明，Tomtor型超富稀有金属矿形成的主要地球化学趋势与风化剖面表面相相反。获得的结果并没有证实独特的 Tomtor 矿石与碳酸岩地壳表面相之间的成因联系，但可以作为它们后来形成的证据，这是由于碳酸岩风化产物在上覆煤层的溶液流失的影响下还原后生的。岩石。