PALEOKARST ROLE IN LEBEDINSKY ORE CLUSTER GOLD OREBODIES LOCALIZATION, YAKUTIA
Keywords:
gold porphyry, gold skarn, gold-quartz-catbonate-sulfide dolomite-hosted deposits, ore-hosting structures, ore-bearing levels, paleokarst.Abstract
Based on long-term study data analysis of Lebedinsky ore cluster gold deposits, Central Aldan, as well as modern prospecting materials, the author’s ideas of this structure paleokarst significance, which determined Late Jurassic to Early Cretaceous Lebedinsky-type ore accumulation environment in Vendian dolomite strata, are validated. Position of extrusive subvolcanic massifs of ore-bearing monzonite-syenite formation containing gold porphyry and gold skarn ores is hypsometrically higher than the main discharge area of associated hydrothermal solutions, which caused the latter to move downward to the main aquiclude, a crystalline basement limiting the ore-controlling karst system at depth.
Crosscutting and stratified elements of cold karst paleosystem host ore veins and related deposits of the lower ore localization levels. Horizons of the most intense karst processes in ore-hosting dolomite strata at contacts with aquiclu- des determined their position at several ore-controlling levels. Localization conditions of the upper level deposits are determined by their formation close to ore-bearing unit massifs involving hydrothermokarst processes. The concept suggesting that Lebedinsky ore cluster structure includes paleokarst system elements as ore-controlling and ore-hosting structures allows to develop new approaches to forecasting and prospecting for such deposits.
