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@article{1199378,
author = {Hönig, Sven and Čopjaková, Renata and Škoda, Radek and Novák, Milan and Dolejš, David and Leichmann, Jaromír and Vašinová Galiová, Michaela},
article_number = {10},
doi = {http://dx.doi.org/10.2138/am-2014-4728},
keywords = {Garnet; EMP; LA-ICP-MS; Y+REE mass-balance calculations; A-type granite; Brno Batholith},
language = {eng},
issn = {0003-004X},
journal = {American Mineralogist},
title = {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.},
url = {http://www.minsocam.org/msa/ammin/AM_Preprints.html},
volume = {99},
year = {2014}
}
TY - JOUR
ID - 1199378
AU - Hönig, Sven - Čopjaková, Renata - Škoda, Radek - Novák, Milan - Dolejš, David - Leichmann, Jaromír - Vašinová Galiová, Michaela
PY - 2014
TI - 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.
JF - American Mineralogist
VL - 99
IS - 10
SP - 1922-1941
EP - 1922-1941
PB - Mineralogical Society of America.
SN - 0003004X
KW - Garnet
KW - EMP
KW - LA-ICP-MS
KW - Y+REE mass-balance calculations
KW - A-type granite
KW - Brno Batholith
UR - http://www.minsocam.org/msa/ammin/AM_Preprints.html
L2 - http://www.minsocam.org/msa/ammin/AM_Preprints.html
N2 - 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.
ER -
HÖNIG, Sven, Renata ČOPJAKOVÁ, Radek ŠKODA, Milan NOVÁK, David DOLEJŠ, Jaromír LEICHMANN a 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. \textit{American Mineralogist}. Mineralogical Society of America., 2014, roč.~99, č.~10, s.~1922-1941. ISSN~0003-004X. Dostupné z: https://dx.doi.org/10.2138/am-2014-4728.
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