Intrusion-related Gold Deposits in Egypt

• 作者: Nagy Shawky BOTROS
• 来源期刊: 地质学报（英文版）
• 年，卷（期）: 2021,（3）
• 所属期刊栏目: REVIEWS
• 页码范围: 1033-1055
• 页数: 23页
• 语种: 英文

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,Ⅱ and Ⅲ). 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 (phase Ⅰ and Ⅱ of 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 phase Ⅲ of the YGs that hosts IRRMDs. A distinct metallogenic epoch comprising both IRGDs and IRRMDs, was undergoing extreme growth at～600 Ma.