Matches in SemOpenAlex for { <https://semopenalex.org/work/W1991976951> ?p ?o ?g. }
- W1991976951 endingPage "424" @default.
- W1991976951 startingPage "405" @default.
- W1991976951 abstract "Shear zone-related, mesothermal gold deposits of Um Egat and Dungash in the Egyptian Eastern Desert are hosted by greenschist facies metavolcanic and/or metasedimentary rocks of Pan-African age. Both deposits comprise boudinaged quartz veins that show evidence of incipient recrystallization, and are similar in alteration style, structural control, and mineralogy. The ore mineralogy includes pyrite, arsenopyrite ± pyrrhotite ± chalcopyrite ± galena; gold occurs both in the veins, usually included in arsenopyrite, pyrite, or pyrrhotite next to fragments of altered country rocks, or disseminated in the alteration haloes. Arsenic in arsenopyrite and Aliv in chlorite geothermometers indicate that wall-rock alteration and ore mineral precipitation occurred at temperatures between 400° and 250°C.Fluid inclusions in vein quartz occur in clusters, or along trails. Three types of fluid inclusions were identified based on petrography and laser micro-Raman spectroscopy: (1) two-phase carbonic inclusions with CO2 + CH4 ± N2 ± H2O, (2) two-phase aqueous inclusions, and (3) three-phase aqueous-carbonic inclusions with CH4. Final melting of ice (Tmf) for most inclusions occurs at temperatures between −4° and 0°C, indicating a low salinity ( 300°C, but cluster into two distinct groups for each type of inclusion. Inclusions from the same trail or cluster are commonly characterized by different degrees of fill or different Th values.Field, petrographic, and microthermometric data suggest that low-salinity aqueous-carbonic fluids interacted with graphite-bearing metasedimentary rocks to form CH4 at T >400°C and P >3 kbars. These reduced fluids leached gold as they circulated through the metavolcanic rocks, carrying it in the form of bisulfide complexes. Interaction of these aqueous-carbonic fluids with the country rocks caused hydrothermal alteration and precipitated gold-bearing sulfides in the alteration zones. A drop of pressure during the migration of these fluids to shallower depths along the shear zones led to phase separation at T ≤300°C and P ≤2.3 kbars. Quartz crystallizing over a range of lower temperatures and pressures trapped carbonic and aqueous fluids as separate inclusions in clusters along pseudosecondary and secondary trails. Postdepositional deformation caused decrepitation of some inclusions, and the stretching and leakage of others, increasing Th to >250°C. Deformation also remobilized the gold, depositing it as globules of higher fineness in secondary sites." @default.
- W1991976951 created "2016-06-24" @default.
- W1991976951 creator A5017362466 @default.
- W1991976951 creator A5025200194 @default.
- W1991976951 creator A5033648601 @default.
- W1991976951 creator A5056332242 @default.
- W1991976951 creator A5080066270 @default.
- W1991976951 date "2008-03-01" @default.
- W1991976951 modified "2023-10-14" @default.
- W1991976951 title "Origin and Evolution of the Um Egat and Dungash Orogenic Gold Deposits, Egyptian Eastern Desert: Evidence from Fluid Inclusions in Quartz" @default.
- W1991976951 cites W1588154159 @default.
- W1991976951 cites W1968490727 @default.
- W1991976951 cites W1976133378 @default.
- W1991976951 cites W1977715511 @default.
- W1991976951 cites W1987939856 @default.
- W1991976951 cites W2014962862 @default.
- W1991976951 cites W2015273598 @default.
- W1991976951 cites W2016738012 @default.
- W1991976951 cites W2019635371 @default.
- W1991976951 cites W2031554685 @default.
- W1991976951 cites W2034467201 @default.
- W1991976951 cites W2036183472 @default.
- W1991976951 cites W2038367243 @default.
- W1991976951 cites W2043959978 @default.
- W1991976951 cites W2045432938 @default.
- W1991976951 cites W2053944321 @default.
- W1991976951 cites W2054962384 @default.
- W1991976951 cites W2061763016 @default.
- W1991976951 cites W2063950649 @default.
- W1991976951 cites W2065969677 @default.
- W1991976951 cites W2069301639 @default.
- W1991976951 cites W2075901285 @default.
- W1991976951 cites W2077423884 @default.
- W1991976951 cites W2081175306 @default.
- W1991976951 cites W2081342672 @default.
- W1991976951 cites W2081729613 @default.
- W1991976951 cites W2082624801 @default.
- W1991976951 cites W2082645751 @default.
- W1991976951 cites W2091973717 @default.
- W1991976951 cites W2094661697 @default.
- W1991976951 cites W2111473359 @default.
- W1991976951 cites W2114745060 @default.
- W1991976951 cites W2115928868 @default.
- W1991976951 cites W2116356169 @default.
- W1991976951 cites W2122143466 @default.
- W1991976951 cites W2144590563 @default.
- W1991976951 cites W2146231114 @default.
- W1991976951 cites W2164269590 @default.
- W1991976951 cites W2168026755 @default.
- W1991976951 cites W2168622143 @default.
- W1991976951 cites W2171765793 @default.
- W1991976951 cites W2344665303 @default.
- W1991976951 cites W2480579518 @default.
- W1991976951 cites W3111851494 @default.
- W1991976951 doi "https://doi.org/10.2113/gsecongeo.103.2.405" @default.
- W1991976951 hasPublicationYear "2008" @default.
- W1991976951 type Work @default.
- W1991976951 sameAs 1991976951 @default.
- W1991976951 citedByCount "51" @default.
- W1991976951 countsByYear W19919769512012 @default.
- W1991976951 countsByYear W19919769512013 @default.
- W1991976951 countsByYear W19919769512014 @default.
- W1991976951 countsByYear W19919769512015 @default.
- W1991976951 countsByYear W19919769512016 @default.
- W1991976951 countsByYear W19919769512017 @default.
- W1991976951 countsByYear W19919769512018 @default.
- W1991976951 countsByYear W19919769512019 @default.
- W1991976951 countsByYear W19919769512020 @default.
- W1991976951 countsByYear W19919769512021 @default.
- W1991976951 countsByYear W19919769512022 @default.
- W1991976951 countsByYear W19919769512023 @default.
- W1991976951 crossrefType "journal-article" @default.
- W1991976951 hasAuthorship W1991976951A5017362466 @default.
- W1991976951 hasAuthorship W1991976951A5025200194 @default.
- W1991976951 hasAuthorship W1991976951A5033648601 @default.
- W1991976951 hasAuthorship W1991976951A5056332242 @default.
- W1991976951 hasAuthorship W1991976951A5080066270 @default.
- W1991976951 hasConcept C111472728 @default.
- W1991976951 hasConcept C127313418 @default.
- W1991976951 hasConcept C138885662 @default.
- W1991976951 hasConcept C151730666 @default.
- W1991976951 hasConcept C17409809 @default.
- W1991976951 hasConcept C1965285 @default.
- W1991976951 hasConcept C2776130869 @default.
- W1991976951 hasConcept C2776152364 @default.
- W1991976951 hasConcept C2779870107 @default.
- W1991976951 hasConcept C7145564 @default.
- W1991976951 hasConceptScore W1991976951C111472728 @default.
- W1991976951 hasConceptScore W1991976951C127313418 @default.
- W1991976951 hasConceptScore W1991976951C138885662 @default.
- W1991976951 hasConceptScore W1991976951C151730666 @default.
- W1991976951 hasConceptScore W1991976951C17409809 @default.
- W1991976951 hasConceptScore W1991976951C1965285 @default.
- W1991976951 hasConceptScore W1991976951C2776130869 @default.
- W1991976951 hasConceptScore W1991976951C2776152364 @default.
- W1991976951 hasConceptScore W1991976951C2779870107 @default.
- W1991976951 hasConceptScore W1991976951C7145564 @default.
- W1991976951 hasIssue "2" @default.