Özet
Gold-sulfide mineralization in the Abu Zawal (Fatira) mine area, North Eastern Desert of Egypt, is related to porphyritic felsite dikes and elongate silicification zones in granitic rocks. These felsite dikes and the host granitic rocks exhibit major and trace element geochemical features typical of calc-alkaline and metaluminous I-type granites, likely originated in a late-orogenic setting. Their geochemical characteristics along with their fractionated LREE relative to HREE patterns imply either formation in a subduction-related environment or generation from subduction-modified source materials. Partial melting of subduction-metasomatized lower crustal rocks during extension following the lithospheric thickening may account for the production of such fertile, high Sr/Y and La/Yb magmas. In the Abu Zawal (Fatira) area, NE-trending altered felsite dikes, hydrothermal breccias, quartz enclaves, and wall-rock replacements are characterized by disseminations of chalcopyrite, pyrite, and rare gold. Alteration mineralogy, dominated by sericite, drusy quartz, kaolinite, calcite, and specular hematite, combined with the available fluid inclusion data suggests moderate to low temperature and near neutral pH conditions. The geochemical data of the altered wallrocks and mass balance calculations indicate significant mass losses in the altered rocks consistent with fluid/wallrock ratios higher than unity and near neutral pH conditions. Considering that the silica-rich host rocks, hydrothermal alteration, and sulfide-bearing hydrothermal quartz breccia in Fatira mine area were intuitively related to sulfur-saturated, oxidized felsic magmatism and associated hydrothermal systems, they are most likely linked to the post-subduction felsite porphyries (post-Hammamat felsites ~ 607 Ma), or pertaining to the late phases of the subaerial high-K calc-alkaline volcanics (Dokhan Volcanics ≤ 620 Ma).
| Orijinal dil | İngilizce |
|---|---|
| Makale numarası | 489 |
| Dergi | Minerals |
| Hacim | 13 |
| Basın numarası | 4 |
| DOI'lar | |
| Yayın durumu | Yayınlandı - Nis 2023 |
Bibliyografik not
Publisher Copyright:© 2023 by the authors.
Finansman
The authors would like to thank the National Science Foundation of China (NSFC: 92162213). They express their gratitude to the group of Geochemistry Research Laboratories, Istanbul Technical University, Turkey (ITU-JAL labs) for providing technical supports during laboratory work. Refaey M. El-Wardany is very grateful to the Geology Department Faculty of Science at Al-Azhar University (Assiut Branch), the China Scholarship Council, and Chang’an University for their support during this research. Amr Abdelnasser would like to thank the Ministry of Higher Education of Egypt as well as the Scientific and Technological Research Council of Turkey (2221-TUBITAK Fellowship Program) for supporting his research stay at Istanbul Technical University (Turkey) as a postdoctoral fellow. The handling editor and three anonymous reviewers are acknowledged for their insightful comments and suggestions that improved the presentation and interpretations of our work. Peter Johnson is thanked for his valued remarks on the early version of this paper.
| Finansörler | Finansör numarası |
|---|---|
| National Natural Science Foundation of China | 92162213 |
| Chang'an University | |
| Ministry of Higher Education, Egypt | |
| Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | |
| China Scholarship Council | |
| Istanbul Teknik Üniversitesi | |
| Al-Azhar University |