Precambrian and Phanerozoic history of gold mineralization in the Bohemian Massif

Moravek, P.; Pouba, Z.

doi:10.2113/gsecongeo.82.8.2098

Cited by 24 publications

(7 citation statements)

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“…The main gold metallogenetic phases in the Bohemian Massif, including the formation of the Mokrsko gold deposit, were temporally and spatially connected with the Variscan orogeny [26,27], which formed the main tectonic units in Western and Central Europe during the Carboniferous time (Figure 1, [28]). Many of the gold deposits in the Bohemian Massif were formed in conjunction with a large granitoid mass of the Variscan Central Bohemian Plutonic Complex (~360-330 Ma [29,30]).…”

Section: Geological Settingmentioning

confidence: 99%

Multi-Stage Evolution of Gold-Bearing Hydrothermal Quartz Veins at the Mokrsko Gold Deposit (Czech Republic) Based on Cathodoluminescence, Spectroscopic, and Trace Elements Analyses

et al. 2018

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We performed a detailed analysis of hydrothermal quartz at the Mokrsko gold deposit (Čelina, Mokrsko-East, and Mokrsko-West deposits). Twenty-one samples were studied by scanning electron microscopy cathodoluminescence (CL) imagining, CL emission spectra and trace elements were measured on six selected samples. Four quartz growth generations Q1 to Q4 were described. Homogeneous early blue CL Q1 with initial emission spectra at 380 and 500 nm was observed at the Čelina deposit with typical titanium concentrations in the range of 20–50 ppm. Hydrothermal quartz at Mokrsko-West, which also includes early Q1, late subhedral faces of yellow CL Q2, and microfissures of greenish CL Q3 (both 570 nm), is characterized by titanium depletion. The titanium concentration is comparable to previous studies of crystallization temperatures proving titanium concentration in quartz as a good geothermal indicator. Q4, developed in microfissures only at Čelina, has no visual CL effect. Mokrsko-West is specific in comparison to Mokrsko-East and Čelina by germanium enrichments in hydrothermal quartz (up to 17 ppm) and the presence of fluorite. Tectonic (sheeted veinlets system, regional tectonic setting) and geochemical (germanium in quartz, the presence of fluorite) characteristics of the quartz veins link the late mineralization stages at the Mokrsko-West deposit to the temporally related Blatná intrusive suite.

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Section: Geological Settingmentioning

confidence: 99%

Multi-Stage Evolution of Gold-Bearing Hydrothermal Quartz Veins at the Mokrsko Gold Deposit (Czech Republic) Based on Cathodoluminescence, Spectroscopic, and Trace Elements Analyses

et al. 2018

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“…This summary of Mokrsko is taken from Moravek and Pouba (1987) and Moravek and others (1989). This summary of Mokrsko is taken from Moravek and Pouba (1987) and Moravek and others (1989).…”

Section: Mokrsko Czechoslovakiamentioning

confidence: 99%

On a proposed plutonic porphyry gold deposit model

Hollister

1992

Nat Resour Res

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A plutonic porphyry gold deposit model is proposed that is similar to the plutonic porphyry copper deposit model. However, unlike the plutonic porphyry copper deposit model, the proposed model is deficient in copper and contains less than 1 percent total sulfides. In the proposed model, gold is accompanied by scheelite, molybdenite, arsenopyrite, a variety of bismuth sulfides, tellurides, and native bismuth. The host rock varies from granite to granodiorite stock. Most of the ore is in the pluton. Deposits cited as examples of the proposed model are the Mokrsko deposit in Czechoslovakia, the Fort Knox deposit in the United States, and the Dublin Gulch deposit in Canada. In each of these deposits, pervasive potassic or phyllic alteration zones accompany the gold ore, which is disseminated in quartz-rich stockworks, veinlet swarms, and veins. Tonnages of gold-bearing material are large, but grades are low in the cited deposits. The proposed model is distinct from other gold deposit models because of the low Cu to Au ratio and the association of Au, Bi, W, and Mo.

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“…Finally, the Pontal gold-bearing quartz vein may be described as a high-temperature metamorphic deposit (Moravek and Pouba, 1987), probably formed under variable oxygen fugacity, with redox conditions ranging from QFM buffer to lower values. A major unresolved problem is the origin of the carbon-bearing fluids: the usual assumption of a source within graphitic shales cannot be invoked, in view of the lack of such sediments in the basement.…”

Section: Interpretations and Conclusionmentioning

confidence: 99%

Multiphase methane-rich fluid inclusions in gold-bearing quartz as illustrated at Pontal (Goias, Brazil)

et al. 1990

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In the Pontal auriferous lode, dominant saccharoidal quartz is associated with oligoclase, biotite, hornblende, tremolite-actinolite, sulphides (less than 2%), and disseminated native gold. Four main types of fluid inclusion have been distinguished based on their habit, distribution and spatial relationship with gold particles. Type S are primary multiphase large sized (100 to 200 p~m) inclusions with homogenization temperatures (V + L-*L) between 350 and 450~ They Contain siderite and/or calcite and graphite-like microcrystals as daughter phases. Commonly associated with these inclusions are tiny (50 to 100 p~m) solid inclusions of biotite or actinolite. In most of these inclusions, only CH4 has been detected in the vapour phase. However some noticeable exceptions were observed (COjCH4 ratio near 0.85). Type C inclusions are later than gold and occur disseminated in quartz or along trails that crosscut quartz grain boundaries. They may contain nahcolite daughter crystals. CO2/CH 4 ratios range from 0.0 to 0.5. Homogenization temperatures vary from 150 to 300 ~ Type V are mainly gaseous CH4-H20 inclusions. They may occur as small-sized inclusions directly associated with gold particles. Type L are aqueous two-phase inclusions of late secondary origin.The scattering of the CO2/CH 4 ratios could be related to fluctuations of the oxygen fugacity that triggered gold precipitation at the time of trapping. These variations of fo2 with time could reflect unbuffered fluid-rock interaction with respect to redox conditions during quartz deposition.Finally, gold deposition is interpreted to have occurred at elevated temperature (500~ and pressure, compatible with boundary conditions between greenschist and amphibolites facies. K E Y W O g O S: gold deposit, quartz lode, fluid inclusions, Raman microprobe, microthermometry.

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Precambrian and Phanerozoic history of gold mineralization in the Bohemian Massif

Cited by 24 publications

References 0 publications

Multi-Stage Evolution of Gold-Bearing Hydrothermal Quartz Veins at the Mokrsko Gold Deposit (Czech Republic) Based on Cathodoluminescence, Spectroscopic, and Trace Elements Analyses

Multi-Stage Evolution of Gold-Bearing Hydrothermal Quartz Veins at the Mokrsko Gold Deposit (Czech Republic) Based on Cathodoluminescence, Spectroscopic, and Trace Elements Analyses

On a proposed plutonic porphyry gold deposit model

Multiphase methane-rich fluid inclusions in gold-bearing quartz as illustrated at Pontal (Goias, Brazil)

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