FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2029145260> ?p ?o ?g. }

• W2029145260 endingPage "470" @default.
• W2029145260 startingPage "445" @default.
• W2029145260 abstract "Although gold production from orogenic deposits in the Arabian–Nubian Shield is currently relatively minor, extensive alluvial and lode fields were exploited by the ancient Egyptians along the western side of the Red Sea in Upper Egypt and northern Sudan. In the Eastern Desert of Egypt, numerous but small gold deposits are generally related to auriferous quartz veins commonly associated with brittle–ductile shear zones cutting the Neoproterozoic crystalline basement rocks. The Um El Tuyor gold deposit, in the extreme south of the Eastern Desert, consists of a series of quartz and quartz–carbonate veins, lenses and veinlets, along foliation-concordant and foliation-discordant fault segments. The orebodies are mainly quartz–carbonate (quartz + Fe-dolomite/ankerite + muscovite/sericite + sulfides ± gold/electrum) and laminated quartz veins (quartz + sericite/chlorite ± graphite ± free gold). Gold appears as microscopic blebs within arsenopyrite and pyrite or along fractures and grain boundaries in quartz veins and finely disseminated grains in mixtures of chlorite ± sericite and carbonate in the wallrock. The bulk vein system is controlled by a NNW- to NW-trending brittle–ductile shear zone, cutting sequences of pelitic metasediments (garnet–biotite schist with intercalations of metamudstone and metagreywacke). Pervasive sericitization, carbonatization and chloritization overprint the metamorphic assemblages in rocks adjacent to the mineralized quartz veins. Temporal and lateral evolution of the ore fluid composition through interaction with the wallrock is inferred from the concentric alteration pattern. Stages of increasing hydrothermal alteration are identified as initial, intermediate and advanced. Hydrolysis reactions by a near acid fluid, whose pH was buffered by the wallrock mineralogy, prevailed in the initial stage. The transitional stage involved intense carbonatization, sulfidation and redox reactions along with hydrolysis. During the advanced stage, intense sericitization consumed K+, released H+, and lowered the solution pH. Sulfidation continued, and unbuffered conditions were locally attained under high fluid/rock ratios. This collectively indicates that the ore fluids evolved progressively towards lower temperatures and sulfur fugacity with time. Clustered and intragranular trail-bound aqueous-carbonic [H2O–NaCl–CO2(± CH4 ± N2)] inclusions are common in cores of the less deformed quartz crystals, whereas carbonic [CO2 ± CH4 ± N2] and aqueous [low salinity H2O–NaCl] inclusions occur along intergranular and transgranular trails. The aqueous-carbonic and aqueous inclusions are common in the quartz–carbonate veins, whereas the carbonic inclusions are by far the dominant — or virtually the sole fluid inclusions — in most parts of the laminated quartz and quartz–carbonate veins. Clathrate melting temperatures indicate low fluid salinities (3 to 8 wt.% NaCl equiv.). Bulk densities and salinities of the aqueous-carbonic inclusions are high in the quartz–carbonate veins compared to those in the laminated quartz veins, further constraining interpretation of the field observations suggesting that the laminated quartz veins were formed through a fault–valve system and cyclic opening and annealing of reactivated quartz–carbonate reefs. Destabilization of gold–bisulfide complexes and lowering of gold solubility through interplay of fluid mixing (± unmixing), cooling, changes in pH and fO2 along with fluid–wallrock interaction brought about gold deposition. In the quartz–carbonate veins, in which the highest Th total (336 °C) indicates a pressure range of 1.7 to 2.1 kbar using isochores for highest and lowest bulk density aqueous-carbonic inclusions. In the laminated quartz veins, gold deposition likely took place due to fluid mixing and fluid–wallrock interaction at ≤ 325 °C at pressures of 1.6 to 1.3 kbar. Gold deposition due to fluid–wallrock interaction (sulfidation) does not conflict with intermittent fluid unmixing or mixing, as the latter does not appear to have extended into the wallrock. Pressure estimates indicate depths of 6 to 8 km for quartz veining and gold deposition in the area, compatible with crustal conditions of greenschist metamorphism and brittle–ductile transition." @default.
• W2029145260 created "2016-06-24" @default.
• W2029145260 creator A5056332242 @default.
• W2029145260 date "2008-11-01" @default.
• W2029145260 modified "2023-10-02" @default.
• W2029145260 title "Characteristics and genesis of shear zone-related gold mineralization in Egypt: A case study from the Um El Tuyor mine, south Eastern Desert" @default.
• W2029145260 cites W1588154159 @default.
• W2029145260 cites W1964259713 @default.
• W2029145260 cites W1968490727 @default.
• W2029145260 cites W1972909865 @default.
• W2029145260 cites W1976815843 @default.
• W2029145260 cites W1976848297 @default.
• W2029145260 cites W1979202704 @default.
• W2029145260 cites W1990029207 @default.
• W2029145260 cites W1994596884 @default.
• W2029145260 cites W1999123171 @default.
• W2029145260 cites W1999154901 @default.
• W2029145260 cites W2002597398 @default.
• W2029145260 cites W2003365107 @default.
• W2029145260 cites W2005925547 @default.
• W2029145260 cites W2008050479 @default.
• W2029145260 cites W2008632542 @default.
• W2029145260 cites W2013577431 @default.
• W2029145260 cites W2015027708 @default.
• W2029145260 cites W2017987352 @default.
• W2029145260 cites W2019635371 @default.
• W2029145260 cites W2024912548 @default.
• W2029145260 cites W2028864413 @default.
• W2029145260 cites W2030315855 @default.
• W2029145260 cites W2031554685 @default.
• W2029145260 cites W2032544550 @default.
• W2029145260 cites W2033878695 @default.
• W2029145260 cites W2041532412 @default.
• W2029145260 cites W2044537972 @default.
• W2029145260 cites W2044649453 @default.
• W2029145260 cites W2045989453 @default.
• W2029145260 cites W2051757039 @default.
• W2029145260 cites W2052163085 @default.
• W2029145260 cites W2054643770 @default.
• W2029145260 cites W2055980863 @default.
• W2029145260 cites W2058473564 @default.
• W2029145260 cites W2063950649 @default.
• W2029145260 cites W2065969677 @default.
• W2029145260 cites W2069301639 @default.
• W2029145260 cites W2070447864 @default.
• W2029145260 cites W2072311942 @default.
• W2029145260 cites W2073250859 @default.
• W2029145260 cites W2075901285 @default.
• W2029145260 cites W2077423884 @default.
• W2029145260 cites W2081149290 @default.
• W2029145260 cites W2081175306 @default.
• W2029145260 cites W2081342672 @default.
• W2029145260 cites W2082645751 @default.
• W2029145260 cites W2085191160 @default.
• W2029145260 cites W2087870474 @default.
• W2029145260 cites W2088168225 @default.
• W2029145260 cites W2088466117 @default.
• W2029145260 cites W2088522209 @default.
• W2029145260 cites W2090666494 @default.
• W2029145260 cites W2094661697 @default.
• W2029145260 cites W2095633464 @default.
• W2029145260 cites W2111053933 @default.
• W2029145260 cites W2116356169 @default.
• W2029145260 cites W2118668493 @default.
• W2029145260 cites W2120270131 @default.
• W2029145260 cites W2122245203 @default.
• W2029145260 cites W2122458595 @default.
• W2029145260 cites W2123802889 @default.
• W2029145260 cites W2140161554 @default.
• W2029145260 cites W2140408185 @default.
• W2029145260 cites W2146231114 @default.
• W2029145260 cites W2151103317 @default.
• W2029145260 cites W2152195282 @default.
• W2029145260 cites W2166351382 @default.
• W2029145260 cites W2174216460 @default.
• W2029145260 cites W2278700438 @default.
• W2029145260 cites W2317337219 @default.
• W2029145260 cites W2480579518 @default.
• W2029145260 cites W2607062484 @default.
• W2029145260 cites W2895330554 @default.
• W2029145260 cites W4234065882 @default.
• W2029145260 doi "https://doi.org/10.1016/j.oregeorev.2008.05.003" @default.
• W2029145260 hasPublicationYear "2008" @default.
• W2029145260 type Work @default.
• W2029145260 sameAs 2029145260 @default.
• W2029145260 citedByCount "49" @default.
• W2029145260 countsByYear W20291452602012 @default.
• W2029145260 countsByYear W20291452602013 @default.
• W2029145260 countsByYear W20291452602014 @default.
• W2029145260 countsByYear W20291452602015 @default.
• W2029145260 countsByYear W20291452602016 @default.
• W2029145260 countsByYear W20291452602017 @default.
• W2029145260 countsByYear W20291452602018 @default.
• W2029145260 countsByYear W20291452602019 @default.
• W2029145260 countsByYear W20291452602020 @default.
• W2029145260 countsByYear W20291452602021 @default.
• W2029145260 countsByYear W20291452602022 @default.
• W2029145260 countsByYear W20291452602023 @default.

• next