Metallogenesis at the Terramonte Pb–Zn–Ag quartz vein, Portugal: Geological, mineralogical and geochemical evidences

Neiva, A.M.R.; Moura, António; Carvalho, P. C. S.

doi:10.1016/j.oregeorev.2015.04.023

Cited by 4 publications

(2 citation statements)

References 72 publications

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“…The mixing is synchronous with the chalcopyrite deposition. The chlorinity decrease due to mixing may have destabilised metal (Zn, Cu, Pb) chloride complexes, and caused metal deposition (Wilkinson, 2001;Heijlen et al, 2003;Boiron et al, 2002Boiron et al, , 2010Neiva et al, 2015;Richard et al, 2016).…”

Section: Triassic Formations As Brine Sourcementioning

confidence: 99%

Evaporitic brines and copper-sulphide ore genesis at Jbel Haïmer (Central Jebilet, Morocco)

Essarraj

Boiron

Cathelineau

et al. 2021

Ore Geology Reviews

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The Jbel Haïmer copper-sulphide mineralisation occurs at 20 km north of Marrakesh in the Variscan Jebilet massif, Morocco. Most of the ores (up to 3.9 wt. % Cu, ≤ 38 ppm Ag, and up to 2.9 ppm Au) occur as impregnations of NE-SW fault/fracture zones and related tectonic breccia. Two independent stages of fluid circulation and mineral deposition are distinguished. First, Late Variscan high temperature-low pressure metamorphism synchronous of granite intrusion induced percolation of C-H-O-N hydrothermal fluids throughout faults and shear zones. The drop in pressure from lithostatic down to hydrostatic values at temperatures around 350 ± 50°C triggered quartz precipitation associated with minor Sn-As-(Co-Ni) deposits and finally brecciation. The second stage, more recent than Triassic, consists in the deposition of quartz + carbonates, followed by Cu-(Pb-Zn) sulphides (±Ag-Au alloys) in fractures crosscutting 240 Ma microdiorite dikes. Mixing of evaporitic brines likely coming from Triassic formations with low salinity aqueous fluids was responsible for Cu-sulphide deposition at temperatures of around 220-280°C at a depth of 4-5 km. These base metal-rich brines are similar to those from the nearby Roc Blanc Ag-deposit and several other silver and base metal deposits in Morocco, considered as having circulated during the Central Atlantic Ocean opening.

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Section: Triassic Formations As Brine Sourcementioning

confidence: 99%

Evaporitic brines and copper-sulphide ore genesis at Jbel Haïmer (Central Jebilet, Morocco)

Essarraj

Boiron

Cathelineau

et al. 2021

Ore Geology Reviews

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“…Variations in FeS content in sphalerite may reflect variations in the activity of FeS in the fluid and in physicochemical conditions during precipitation [74]. Also, variation in the mol % FeS of sphalerite coexisting with pyrite and pyrrhotite reflects the variability of the sulfidation state in a given system and provides useful information in classifying an epithermal deposit [75][76][77].…”

Section: Geochemistry Of Ore Mineralsmentioning

confidence: 99%

The Shah-Ali-Beiglou Zn-Pb-Cu (-Ag) Deposit, Iran: An Example of Intermediate Sulfidation Epithermal Type Mineralization

et al. 2018

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The Shah-Ali-Beiglou epithermal base metal-silver deposit is located in the Tarom-Hashjin metallogenic province (THMP) in northwestern Iran. This deposit is hosted by quartz monzonite dikes of Oligocene age and surrounded by andesite to trachyandesite volcanic and volcaniclastic rocks of Eocene age. The subvolcanic rocks in the study area vary in composition from quartz-monzonite to monzonite and have metaluminous, calc-alkaline to shoshonitic affinity. These rocks have I-type geochemical characteristic and are related to post-collisional tectonic setting. The mineralization occurs as NE-SW and E-W-trending brecciated veins controlled by strike-slip and normal faults, which are associated to the Late Oligocene compressional regime. The mineral paragenesis of the vein mineralization is subdivided into pre-ore stage, ore stage, post-ore stage, and supergene stage. Pre-ore stage is dominated by quartz, sericite, and subhedral to anhedral pyrite as disseminated form. Ore-stage is represented by quartz, sphalerite (from 0.1 mol % to 4 mol % FeS), galena, chalcopyrite, tetrahedrite-tennantite, minor seligmannite and enargite, as vein-veinlet, cement and clast breccias. Post-ore stage is defined by deposition of quartz and carbonate along with minor barite, and supergene stage is characterized by bornite, chalcocite, covellite, hematite, goethite, and jarosite. The ore mineralization is associated with the silicic alteration. The styles of alteration are silicic, carbonate, sericitic, chloritic, and propylitic. Fluid inclusions in sphalerite have a wide range of salinities between 0.35 wt % and 21.4 wt % NaCl equivalent and homogenization temperatures range from 123 to 320 • C. The isotopic values of sulfides vary from 2.8 to 6.7 suggesting a magmatic source for the sulfur. In the present study, based on geological setting, alteration style of the host and wall rocks, main textures, mineral assemblages, composition of ore minerals, and structural features, it is suggested that the mineralization in the Shah-Ali-Beiglou is similar to intermediate-sulfidation style of epithermal deposits.

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The Koudia El Hamra Ag–Pb–Zn deposit, Jebilet, Morocco: Mineralogy and ore fluid characterization

Nshimiyimana

Essarraj

Hibti

et al. 2018

Journal of African Earth Sciences

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Metallogenesis at the Terramonte Pb–Zn–Ag quartz vein, Portugal: Geological, mineralogical and geochemical evidences

Cited by 4 publications

References 72 publications

Evaporitic brines and copper-sulphide ore genesis at Jbel Haïmer (Central Jebilet, Morocco)

Evaporitic brines and copper-sulphide ore genesis at Jbel Haïmer (Central Jebilet, Morocco)

The Shah-Ali-Beiglou Zn-Pb-Cu (-Ag) Deposit, Iran: An Example of Intermediate Sulfidation Epithermal Type Mineralization

The Koudia El Hamra Ag–Pb–Zn deposit, Jebilet, Morocco: Mineralogy and ore fluid characterization

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