Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: a case study from the Bohemian Massif (Czech Republic)

Breiter, Karel; Gardenová, Nina; Kanický, Viktor; Vaculovič, Tomáš

doi:10.2478/geoca-2013-0018

Cited by 53 publications

(16 citation statements)

References 36 publications

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“…In Harker-type diagrams, however, the biotite and the calcic granites do not show a continuum; rather, they present two parallel trends (Fig. 5), with no significant variation in highly incompatible elements, including Ga, which can be used as a fractionation index in granitic systems (Breiter et al, 2013).…”

Section: Did the Main Granite Types Have A Similar Source?mentioning

confidence: 98%

Systematic mineralogical diversity in A-type granitic intrusions: Control of magmatic source and geological processes

Papoutsa¹,

Pe‐Piper²,

Piper³

2015

Geological Society of America Bulletin

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The origin and causes of mineralogical diversity of A-type granites are debated. The series of A-type granite plutons, with distinct mineralogical differences, emplaced along an Upper Paleozoic crustal-scale shear zone in the Cobequid Highlands, Nova Scotia, provide an opportunity to examine the origin of different A-type plutons in a similar tectonic setting. Based on the ferromagnesian minerals present, the plutons are classified into sodic granites with sodic amphibole, calcic granites with calcic amphibole, and biotite granites. Sodic and calcic granites occur exclusively in complex intrusions with subequal amounts of gabbro in the eastern shear zone, whereas plutons in the western shear zone, with lesser gabbro, are solely biotite granites. Trace elements and radiogenic isotopes show that the three granite types have different sources. Intensive parameters including temperature, pressure, and water-in-melt contents were esti mated from mineralogical and geochemical data. Modeling of these geochemical data suggests that the biotite and calcic granites were derived by 20%-40% partial melting of intra crustal feldspathic rocks, whereas the sodic granites are extreme fractionates (90%) of coeval mafic magma. We propose that supply of Upper Paleozoic mafic magma, probably related to regional extension and decompression melting beneath the Magdalen Basin, created a deep crustal hot zone in the eastern Cobequid Highlands, and extreme fractionation of underplated mafic sills produced the sodic granites. Heat transfer from crystallizing mafic magma induced partial melting of the surrounding crust, creating batches of biotite and calcic granitic melts in different depths. Fractionated and crustally derived melts segregated along crustal-scale faults, constructing the complex plutons in the east. Melting of the crust was further facilitated by the release of water from the crustal rocks upon heating. In the eastern shear zone, water was released predominantly by magmatic rocks and in lesser amounts compared to the west, where Neoproterozoic sedimentary and volcani clastic rocks are more abundant. The volatile-rich granitic melts in the western part of the shear zone were crystallized rapidly, stabilizing only biotite. This study demonstrates that the mineralogical variations in A-type granites arise from rather similar magma compositions, but they are important petrogenetic indicators of varying sources, specific magmatic processes, and emplacement conditions.

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Section: Did the Main Granite Types Have A Similar Source?mentioning

confidence: 98%

Systematic mineralogical diversity in A-type granitic intrusions: Control of magmatic source and geological processes

Papoutsa¹,

Pe‐Piper²,

Piper³

2015

Geological Society of America Bulletin

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“…The presence of Ge and Ga in hydrothermal fluids probably derives from enrichment during the fractional crystallization processes of igneous rocks (Breiter et al, 2013), or they were derived from the country rocks, particularly from those containing organic material (Bernstein, 1985; Höll et al , 2007). According to the latter authors, the behaviour of Ge appears to be dependent on the sulfur fugacity conditions whereby Ge enters the structure of sphalerite in low to moderate sulfur activity and forms its own phases under higher fugacity of sulfur.…”

Section: Discussionmentioning

confidence: 99%

Enrichment in critical metals (In-Ge) and Te-Se in epithermal deposits of the ‘La Carolina’ district, San Luis, Argentina

et al. 2018

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Epithermal Au-Ag deposits of the La Carolina district, in the San Luis metallogenetic belt (Argentina), are related spatially and genetically to Mio-Pliocene volcanism. In this district, mineralization in the Cerro Mogote and Puesto La Estancia prospects occur as disseminations, veins and fracture/cavity infillings in volcanic/pyroclastic rocks, metamorphic basement and hydrothermal breccias. The gangue assemblage is dominated by carbonates (siderite, rhodochrosite, kutnahorite, dolomite). The main sulfides are pyrite, sphalerite, galena and chalcopyrite. Pyrite and sphalerite have compositional zoning, the former with As-rich cores and Cu-rich overgrowths, the latter with Fe-rich and Fe-poor bands. Sphalerite shows variable contents of Mn, Cu, In, Ga, Ge and Ag. The In-richest sphalerite hosts up to 5940 ppm In but also contains elevated concentrations of Cu, Ag, Ga and Ge, suggesting a coupled substitution mechanism resulting in enrichments in monovalent (Ag+, Cu+) and trivalent-tetravalent cations (Ga3+, In3+, Ge4+). The main precious metal minerals are Ag-rich tetrahedrite, acanthite, argyrodite, pearceite–polybasite and Au-Ag alloy. Locally, Se and/or Te-enriched minerals include galena Pb(S0.9–1Se0.1–0), hessite Ag2(Te0.9–1Se0.1–0), Se-rich cervelleite Ag4(Te1.3–0.9S1–0.5 Se0.5–0.2), and also alburnite [Ag8GeTe2S4] and benleonardite [Ag15Cu(As,Sb)2S7Te4]. Pearceite contains Te (3.6–4.3 wt.%) and Se (1–2.3 wt.%) substituting for S, which are unusually high concentrations for this mineral. The Puesto La Estancia deposit contains various tellurides including sylvanite, petzite, stutzite, altaite, tellurobismuthite and volynskite. This study shows that the chemistry of the fluids fluctuated during ore deposition suggesting different fluid pulses (system rejuvenation and/or boiling). The enrichment in Te, Se and Bi enrichment is supportive of a magmatic contribution to the ore fluid, while graphite in the metamorphic basement could be the source of germanium, although a magmatic source cannot be ruled out.

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“…DOI: https://doi.org/10.2138/am-2021-7838. http://www.minsocam.org/ concentration in pegmatites and quartz-topaz greisens (Bernstein, 1985;Höll et al, 2007;Breiter et al, 2013). Trace elements found in euclase samples from other localities (Sharp, 1961;Graziani and Guidi, 1980;Hanson, 1985), such as Na, K, Ca, Sc, Cu or Sn, were not detected.…”

Section: Methodsmentioning

confidence: 97%

Mn3+ and the pink color of gem-quality euclase from northeast Brazil

Gilles-Guéry,

Galoisy,

Schnellrath

et al. 2022

American Mineralogist

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Pink euclase of gem-quality and centimeter size, presenting an unusual pink-orange coloration and a pink to orange pleochroism, has been discovered near Livramento de Nossa Senhora, in Bahia State, Brazil. The origin of the pink coloration has been investigated using different spectroscopic techniques: UV-Vis-NIR spectroscopy, Electron Paramagnetic Resonance (EPR), luminescence and X-ray Absorption Near Edge Structure (XANES). The coloration is mainly due This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

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Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: a case study from the Bohemian Massif (Czech Republic)

Cited by 53 publications

References 36 publications

Systematic mineralogical diversity in A-type granitic intrusions: Control of magmatic source and geological processes

Systematic mineralogical diversity in A-type granitic intrusions: Control of magmatic source and geological processes

Enrichment in critical metals (In-Ge) and Te-Se in epithermal deposits of the ‘La Carolina’ district, San Luis, Argentina

Mn3+ and the pink color of gem-quality euclase from northeast Brazil

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