HÖNIG, Sven, Renata ČOPJAKOVÁ, Radek ŠKODA, Milan NOVÁK, David DOLEJŠ, Jaromír LEICHMANN and Michaela VAŠINOVÁ GALIOVÁ. Garnet as a major carrier of the Y and REE in the granitic rocks: An example from the layered anorogenic granite in the Brno Batholith, Czech Republic. American Mineralogist. Mineralogical Society of America., 2014, vol. 99, No 10, p. 1922-1941. ISSN 0003-004X. Available from: https://dx.doi.org/10.2138/am-2014-4728.
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Basic information
Original name Garnet as a major carrier of the Y and REE in the granitic rocks: An example from the layered anorogenic granite in the Brno Batholith, Czech Republic.
Authors HÖNIG, Sven (203 Czech Republic, guarantor, belonging to the institution), Renata ČOPJAKOVÁ (203 Czech Republic, belonging to the institution), Radek ŠKODA (203 Czech Republic, belonging to the institution), Milan NOVÁK (203 Czech Republic, belonging to the institution), David DOLEJŠ (203 Czech Republic), Jaromír LEICHMANN (203 Czech Republic, belonging to the institution) and Michaela VAŠINOVÁ GALIOVÁ (203 Czech Republic, belonging to the institution).
Edition American Mineralogist, Mineralogical Society of America. 2014, 0003-004X.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10500 1.5. Earth and related environmental sciences
Country of publisher United States of America
Confidentiality degree is not subject to a state or trade secret
WWW URL
Impact factor Impact factor: 1.964
RIV identification code RIV/00216224:14310/14:00076613
Organization unit Faculty of Science
Doi http://dx.doi.org/10.2138/am-2014-4728
UT WoS 000342956700011
Keywords in English Garnet; EMP; LA-ICP-MS; Y+REE mass-balance calculations; A-type granite; Brno Batholith
Tags AKR, rivok
Changed by Changed by: Ing. Andrea Mikešková, učo 137293. Changed: 8/4/2015 13:42.
Abstract
Garnet and other rock-forming minerals from A-type granite dykes in the Pre-Variscan Brno Batholith were analyzed to determine relative contributions of individual minerals to whole-rock Y and REE budget and to assess incorporation mechanisms of these elements in garnet. Minor to accessory garnet (<2 vol%) is the essential reservoir for Y+REE in the Hlína granite accounting ~84% Y and 61% REE of the total whole-rock budget. Zircon is another important carrier of REE with ~13% Y and ~11% REE. At least ~21% REE and 1% Y were probably hosted by Th- and U-rich monazite that has been completely altered to a mixture of secondary REE-bearing phases. The contribution of major rock-forming minerals (quartz and feldspars) is low (~1% Y; 10% LREE; ~1% HREE) excluding Eu, which is hosted predominantly by feldspars (~90%). Minor to accessory muscovite and magnetite incorporate ~1% Y and ~2% REE of the whole-rock budget. Magmatic garnet Sps41–46Alm28–44And0–13 Grs6–12Prp0–1 is Y- and HREE-rich (up 1.54 wt% Y; up ~1 wt% total REE), and the Y+REE enter the garnet structure via the menzerite-(Y) substitution. The Y and REE show complex zoning patterns and represent sensitive indicator of garnet evolution, in contrast to a homogeneous distribution of major divalent cations. General outward decrease of Y+REE is a common feature due to the strong partitioning of Y+HREE in the garnet relative to the other phases. REE underwent significant fractionation during growth of early garnet I; the YbN/NdN ratio generally decreases from the core to rim of garnet I. Higher Mn and Al, lower Ca, and Y+REE contents, as well as higher YbN/NdN ratio and more negative Eu anomaly in garnet II overgrowths indicate its crystallization from a more evolved melt. Application of zircon saturation geothermometry provides upper temperature limit of 734 ± 14 °C for the closed-system crystallization. Mineral equilibria reveal that crystallization started at QFM + 1.2, and preferential sequestration of Fe3+ into garnet and magnetite was responsible for progressively reducing conditions. Equilibrium between magnetite, garnet, quartz, and plagioclase, representing the final crystallization stage of the granitic magma, occurred at 658–663 °C and QFM 0 to + 0.8, hence at undercooling of ~75 °C.
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CZ.1.05/1.1.00/02.0068, interní kód MUName: CEITEC - středoevropský technologický institut (Acronym: CEITEC)
Investor: Ministry of Education, Youth and Sports of the CR, CEITEC - Central European Institute of Technology, 1.1 European Centres of Excellence
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