Intrusion-related Gold Deposits in Egypt  

作　　者：Nagy Shawky BOTROS 

机构地区：[1]Egyptian Mineral Resources Authority,Abbassia,Cairo,Egypt

出　　处：《Acta Geologica Sinica(English Edition)》2021年第3期1033-1055,共23页地质学报（英文版）

摘　　要：Intrusion-related gold deposits(IRGDs)occur in the Eastern Desert(ED)of Egypt within magmatic districts that are exploited for tungsten and tin mineralization.IRGDs and intrusion-related rare metal deposits(IRRMDs)are almost invariably linked with the late to post collisional Younger Granites(YGs)that have three successive phases(Ⅰ,ⅡandⅢ).At~635–630 Ma,the ED underwent a transition in deformation style from compressional to extensional and a switch from subduction with crustal thickening to delamination with crustal thinning.This transition was concurrent with the emplacement of a short magmatic pulse(~635–630 Ma)that represents a transition between orogenic gold deposits and IRGDs.K-rich calc alkaline granites(phaseⅠandⅡof the YGs)hosting IRGDs like the Hangalia deposit were emplaced during the time span 630–610 Ma.Alkaline magmatism began at 610 Ma,coexisting with the K-rich calc-alkaline magmatism over the 610–590 Ma time span,where the Fawakhir(598±3 Ma)and Um Had(596±2 Ma)granites that host the IRGDs were emplaced.In time,the alkaline magmatism became more alkaline giving rise to phaseⅢof the YGs that hosts IRRMDs.A distinct metallogenic epoch comprising both IRGDs and IRRMDs,was undergoing extreme growth at~600 Ma.

关 键 词：intrusion-related gold deposits intrusion-related rare metal deposits delamination crustal melting metallogenic epoch ~600 Ma Younger Granites 

分 类 号：P618.51[天文地球—矿床学]