Characteristics and nature of gold-bearing fluids in Fatira area, North Eastern Desert of Egypt: possible transition from intrusion-related to orogenic deposits
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F20%3A00117218" target="_blank" >RIV/00216224:14310/20:00117218 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1007/s12517-020-05982-8" target="_blank" >https://doi.org/10.1007/s12517-020-05982-8</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s12517-020-05982-8" target="_blank" >10.1007/s12517-020-05982-8</a>
Alternative languages
Result language
angličtina
Original language name
Characteristics and nature of gold-bearing fluids in Fatira area, North Eastern Desert of Egypt: possible transition from intrusion-related to orogenic deposits
Original language description
The gold lode in Fatira area is represented in three modes of occurrence: (1) altered felsite dykes, (2) massive quartz veins that are cutting through the hosting granitic rocks, and (3) siliceous-hybrid shear zone which is trending in NNW-SSE direction and separating between metavolcanic and granitic rocks. Metavolcanic rocks are described by meta-andesite and meta-dolerite varieties; they exhibit calc-alkaline magma type related to island arc system. However, granitic rocks are of I-type granodiorite composition with calc-alkaline affinity developed in convergent plate environment (island arc/active continental margins) during the late stage of orogeny. The wallrock alteration around the ore body includes propylitization, sericitization, and silicification facies. The ore minerals were observed as disseminated sulfides (pyrite, sphalerite, chalcopyrite, and covellite). Goethite, jarosite, and ilmenite are the main iron-rich mineral phase as well as malachite and rutile. Gold was detected by microprobe analysis within the internal composition of pyrite and/or jarosite. Two groups of fluid inclusions could be recognized in samples from different mineralized zones: (a) aqueous fluid inclusions (H2O-NaCl/KCl) and (b) aqueous-carbonic fluid inclusions (H2O-CO2-NaCl/KCl). Isochore construction from fluid inclusion data, combined with chlorite thermometry from alteration zone, revealed that Fatira gold deposits were formed at temperature range of 275-297 degrees C and pressure between 0.2 and 1.1 kb). The Fatira gold deposits exhibit similar features of both intrusion-related and orogenic deposits. Hence, the initial ore-bearing fluid was proposed to have originated from magmatic source at deeper levels related to the granitic emplacement (5-10 kb); moreover, the granitic batholith acted as an important vehicle for driving of the metamorphic hydrothermal currents and probably as a cause for the metamorphic process itself. Then, the migration of gold was taken place in form of bi-sulfide complexes and the final deposition occurred through fluid uplifting consequent with a possibility of mixing with meteoric water at shallow depths, pressure/temperature drop, and fluid/wallrock interactions.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
—
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Arabian Journal of Geosciences
ISSN
1866-7511
e-ISSN
1866-7538
Volume of the periodical
13
Issue of the periodical within the volume
19
Country of publishing house
DE - GERMANY
Number of pages
24
Pages from-to
1-24
UT code for WoS article
000576179900003
EID of the result in the Scopus database
2-s2.0-85091718982