Další formáty:
BibTeX
LaTeX
RIS
@article{1415284,
author = {Monsef, Mohamed Abd El and Salem, Ibrahim and Slobodník, Marek and Ragab, Ahmed},
article_number = {2018},
doi = {http://dx.doi.org/10.1016/j.jafrearsci.2018.03.031},
keywords = {Intrusion-related deposits; Geochemistry; EMPA; Fluid inclusions; Um Balad; Egypt},
language = {eng},
issn = {1464-343X},
journal = {Journal of African Earth Sciences},
title = {Fluid evolution of Au-Cu zones in Um Balad area, North Eastern Desert of Egypt: Implications from mineral chemistry and fluid inclusions},
url = {https://www.sciencedirect.com/science/article/pii/S1464343X18300918?via%3Dihub},
volume = {143},
year = {2018}
}
TY - JOUR
ID - 1415284
AU - Monsef, Mohamed Abd El - Salem, Ibrahim - Slobodník, Marek - Ragab, Ahmed
PY - 2018
TI - Fluid evolution of Au-Cu zones in Um Balad area, North Eastern Desert of Egypt: Implications from mineral chemistry and fluid inclusions
JF - Journal of African Earth Sciences
VL - 143
IS - 2018
SP - 321-338
EP - 321-338
SN - 1464343X
KW - Intrusion-related deposits
KW - Geochemistry
KW - EMPA
KW - Fluid inclusions
KW - Um Balad
KW - Egypt
UR - https://www.sciencedirect.com/science/article/pii/S1464343X18300918?via%3Dihub
N2 - Scanning electron microscope (SEM), Electron microprobe (EMPA) and fluid inclusion studies of the ore body, as well as geochemical analyses of country rocks were performed to determine the nature and characteristics of the mineralizing fluid responsible for Au-Cu deposits in Um Balad area, Northern Eastern Desert of Egypt. The Um Balad Au-Cu deposits are confined to well developed-quartz veins and veinlets cutting through the hosting country rocks. Petrographic and geochemical investigations of the hosting rocks distinguished between two main rock units; 1) metagabbro-diorite rocks with tholeiitic nature derived in island arc/continental margin tectonic regime, and 2) granodiorite rocks formed from calc-alkaline magma in continental margin regime. Wallrock alterations are represented by propylitic and argillic types. The mineralized quartz veins are striking in NE-SW direction and dipping between (35e45) in SE direction, other mineralized mafic dykes enriched with auriferous quartz veinlets are trending NE-SWand dipping 70/SE. The main ore minerals are represented by gold, chalcopyrite, pyrite, sphalerite, malachite, covellite and goethite. While, geffroyite, cuprite, chrysocolla, pseudomalachite, britholite, wolframite, scheelite, hematite and rutile are detected as minor constituents. Fluid inclusions microthermometry and isochore calculations combined with chlorite geothermometry revealed that the Um Balad deposits were formed at temperature ranging from 305 C to 325 C and pressure between (100e500 bar). The mineralization had been developed in the shallow levels, beneath the water table at depth of 350e1760 m, rather than common mesothermal vein-type deposits in Egypt. Magmatic water have been suggested as the main source for the mineralized fluid. The transportation of the gold metal seems to be happen as bisulfide complexes in moderately acidic environment. The deposition was resulted from combination of changes in physico-chemical parameters, temperature and pressure plus the instability of the reduced sulfur complexes. A contamination with metamorphic and/or meteoric water was also proposed that has strong influence during the depositional process.
ER -
MONSEF, Mohamed Abd El, Ibrahim SALEM, Marek SLOBODNÍK a Ahmed RAGAB. Fluid evolution of Au-Cu zones in Um Balad area, North Eastern Desert of Egypt: Implications from mineral chemistry and fluid inclusions. \textit{Journal of African Earth Sciences}. 2018, roč.~143, č.~2018, s.~321-338. ISSN~1464-343X. Dostupné z: https://dx.doi.org/10.1016/j.jafrearsci.2018.03.031.
|
