Geological characteristics and ore-control condition of sandstone-type copper deposit in Yuan-Ma Basin,Hunan province

Yuan-Ma basin is one of the most important copper metallogenic regions in Hunan province.The copper deposits in Yuan-Ma basin have the characteristics of large scale,high grade and ore metallurgical performance etc.It has significance to provide scientific basis and mineralization background information for reevaluating sandstone-type copper deposits in Yuan-Ma basin and expanding the periphery prospecting by researching sandstone-type copper metallogenic geological background in Yuan-Ma basin and its control on sandstone-type copper deposits.Based on the geological characteristics of Mayang copper deposits and some previous information,the mineralization conditions and ore controlling factors of the sandstone-type copper deposits in Yuan-Ma basin are researched.It shows that the distribution of ore bodies are mainly restricted by petrographic and tectonics in space.A lithology combination for minerals with the copper bearing rock series"red layer"and "light"cross.Groundwater plays an important role in the oreforming process of the rock debris of copper leaching from the leaching from copper migration to the weak alkaline environment litho tectonic favorable sites for poly metallogenic.The biological organic matter plays an important role on the copper adsorption and reduction,dissolution and migration and enrichment of thecopper.Studies suggest that the formation of joint control by material source deposits,ancient structures,lithofacies,groundwater activities and organic matter and other factors that is based on the geological characteristics of Yuan-Ma sandstone-type copper deposit.The deposit is mainly mechanical deposition,after superposition of hot brine underground ore transformation and ultimately the formation of sandstone-type copper.At last,the favorable prospecting areas are pointed.