Mineralization responses of the Lala copper deposit in Huili,Sichuan to the Neoproterozoic tectonic-magmatic events within the Huili-Dongchuan aulacogen

The Huili-Dongchuan aulacogen extending across Sichuan and Yunnan is an important Proterozoic copper metallogenic province in China,and the Jinningian is a major metallogenic period during the Neoproterozoic.This long period of metallogenesis spanned the folding and closure stage(1 000-900 Ma) and mantle upwelling and extensional stage(900-740 Ma) of the aulacogen.During the folding and closure stage of the aulacogen,the N-S-trending compression facilitated the reactivation and migration of the ore-forming elements from the ore horizons,and concentration of the ore-forming matter.The gabbro emplacement is interpreted as an important magmatic event within the Huili-Dongchuan aulacogen in response to the breakup of supercontinent Rodinia during the mantle upwelling and extensional stage.The relationship between the gabbro emplacement and copper deposit distribution shows that abundant heat derived from the gabbro emplacement has provided powerful thermal dynamics for the reactivation,migration and concentration of the ore-forming elements from the ore horizons,and finally facilitated the enrichment of abundant metallic elements in the Lala region,Sichuan.