Щодо використання формації давніх кір вивітрювання під час пошуків алмазних родовищ
| Autor: | M. M. Zinchuk |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Мінеральні ресурси України. :24-32 |
| ISSN: | 2707-8698 1682-721X |
| Popis: | Complex research of Late Devonian – Early Carboniferous and Middle-Late Triassic weathering crusts on various rocks (terrigenous-carbonate formations, dolerites, tuffs, tuffaceous formations and kimberlites) indicated that in conditions of warm and humid climate corresponding formations of weathering crusts were generated. Complicated multicomponent composition of primary rocks conditioned slow transformation of initial material during crust formation, whereby formation of weathering crusts suspended, often at starting stages. Development of incomplete profiles of weathering was caused, first of all, by weak removal of bivalent cations from primary minerals. Newly arising phases will be dioctahedral and quite often preserve mixed constitution of structural cations. Established typomorphic differences in composition of each type of weathering crusts may be successfully used when upgrading technique of prospecting works on diamonds. At the same time, the issues of establishing the erosion and redeposition of the weathering products of the various rocks into correlative trills of the upper paleoscale of the main diamondiferous regions of the Siberian platform and becoming more important. During the formation of products of washout and redeposition under conditions of accumulation of deluvial-proluvial, proluvial-alluvial and lacustrine factions near kimberlite pipes, diamond placers were formed. With an abundant introduction of terrigenous material alien to the region in alluvial facies strata eroded kimberlite material was greatly diluted due to non-diamondiferous formations. The highest concentrations of local (including kimberlite) material are recorded in the basalt horizons of the Lower Paleozoic Lapchansk Formation which is a formation of woody weathering crusts. In the Mesozoic with the northeastern flank of the Angara-Vilyni superimposed Mesozoic trough the formation of deposits enriched with the products of products of washout and redeposition of CV zone, there were the most favorable. In this structural-formation concentration of eluvial products and the formation of diamond-bearing placers. In the other southern zone of the AVNMP, where alluvial flows outside the region are carried out local material, the conditions for the formation of diamond-bearing placers were unfavorable. All this underlines the importance of studying the formation of ancient Weathering crusts in fore casting and approaching diamond deposits. |
| Databáze: | OpenAIRE |
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