Abstract
New geochemical data of the hydrothermal alteration zones associated with gold-bearing quartz veins at Atud mine are used for better understanding the ore evolution and exploration vectoring. ASTER and Landsat 8 OLI data are used to elucidate the distribution of gold-associated alteration zones. Three alteration zones are defined; zone 1 (sericite-kaolinite-quartz-pyrite), zone 2 (quartz-sericite-albite-pyrite), and zone 3 (chlorite-carbonate-epidote ± pyrite). Sericite and hydrothermal quartz are confined to the mineralized quartz veins. Fe-OH and OH-bearing minerals are observed along NW- and NE-trending shear zones in the Main Atud mine. The association of gold-bearing quartz veins and sericite alteration is constrained by processing ASTER- and OLI-imagery data. The geochemical data of the ore-enveloping hydrothermally altered rocks are used to assess the behavior of the REEs during the mineralization process. Mild enrichment in LREE and significant enrichment in the HREE are associated with sericite in zones (1) and (2) alterations. Carbonate alteration (zone 3) is enriched in LREE and in immobile HREE. Moreover, LREE and Eu anomalies have negative correlated with the Alteration Index (A.I.) and K2O index (K.I.) in zones 1 and 2, suggesting high mobility of LREE in K-rich hydrothermal fluids. On the other hand, HREE anomalies with increasing MgO index (M.I.) in alteration zone 3 may imply low solubility of these elements in alkaline solutions. Au anomalies linked to sericite/silica alteration is a rather meaningful vector for further exploration in the area.
| Original language | English |
|---|---|
| Pages (from-to) | 317-330 |
| Number of pages | 14 |
| Journal | Journal of African Earth Sciences |
| Volume | 145 |
| DOIs | |
| Publication status | Published - Sept 2018 |
Bibliographical note
Publisher Copyright:© 2018 Elsevier Ltd
Funding
This contribution builds on the Ph.D. thesis of the first author. The study was possible through a scholarship sponsored by the Egyptian-Turkish cultural and mission cooperation program Government (YTB, Turkey). It was also supported by the BAP Project (No. 39183 ) for the graduate students by Istanbul Technical University . Thanks should go to the group of the ITU/JAL (Turkey) for their help during the laboratory work. Additionally, the authors are much more grateful to Professor Dr Zakaria Hamimi (Guest Editor of the special issue “Geology, tectonics and mineralizations of the East African Orogen”) and two anonymous reviewers for their constructive comments and helpful suggestions, which greatly improved the manuscript.
| Funders | Funder number |
|---|---|
| Istanbul Teknik Üniversitesi |
Keywords
- ASTER imagery data
- Atud gold deposit
- Egypt
- Hydrothermal alteration
- Landsat 8 OLI data
- REE geochemistry
