Early stages of the Paleoasian Ocean formation: Results of geochronological, isotopic, and geochemical investigations of Late Riphean and Vendian-Cambrian complexes in the Central Asian Foldbelt

Abstract

The Mukodek gold field is discussed as an example proving that dynamometamorphism is a major factor in the formation of gold deposits in the Abchad fault zone.This deposit belongs to the gold-silver-ore zones of mylonitization and schistosity.The ore source is related to the original host rocks with an increased geochemical background concentration of Au.Due to dynamometamorphism processes, gold particles are abundant and mostly enlarged.From the primary rocks, the dynamometamorphites inherit a positive correlation between the number of particles and the concentrations of gold.The dynamometamorphic complex of the ore field developed in two stages, as a minimum.At the early stage (321.0±1.9Ma), the host rocks were mechanochemically deformed and transformed into the goldbearing mineralized dynamometamorphites containing sericite, chlorite, ankerite, albite, and quartz.In the second stage (280±15 Ma), the albite-dolomite-quartz ore veins were formed.Such veins have industrial gold contents.