Complex magmatic and subsolidus compositional trends of
columbite-tantalite in the beryl-columbite Sejby granitic
pegmatite, Czech Republic: role of crystal-structural
constraints and associated minerals

J 2018

Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals

NOVÁK, Milan; Stepan CHLADEK; Pavel UHER a Petr GADAS

Základní údaje

Originální název

Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals

Autoři

NOVÁK, Milan; Stepan CHLADEK; Pavel UHER a Petr GADAS

Vydání

Journal of Geosciences, Praha, Česká geologická společnost, 2018, 1802-6222

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Full Text

Impakt faktor

Impact factor: 1.275

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/18:00111284

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

columbite-group minerals; tapiolite; compositional trends; Nb-Ta and Fe-Mn fractionation; granitic pegmatite

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 11. 5. 2020 10:08, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

The simply zoned Sejby pegmatite of beryl-columbite subtype is enclosed in migmatitized gneisses - country rocks of the southern part of the Central Moldanubian Plutonic Complex, Bohemian Massif, Czech Republic. The columbite-group minerals (CGM) occur mostly in blocky K-feldspar unit. Primary magmatic CGM [columbite-(Fe)-tantalite-(Fe)], show an interesting compositional and textural evolution. Subhomogeneous cores of columbite-(Fe)-tantalite-(Fe) (A) are surrounded by heterogeneous intermediate zones (B) and (C) with irregular to oscillatory zoning and mutually comparable compositions. Zone (B) contains grains of tapiolite-(Fe) and inclusions of pyrite decomposed into a mixture of secondary jarosite-group minerals. In the next zone (C), irregular Mn-enriched patches occur and in the outermost thin zone (D) CGM exhibit fine oscillatory zoning typically developed at crystal terminations. The late, subsolidus CGM include patchy-zoned Mn-enriched columbite-(Fe) and late columbite-(Fe) veinlets both formed at the expense of their magmatic precursors in the zone C; the veinlets are also present in the zone D. Similar but fine patches and veinlets are developed around jarosite pseudomorphs after pyrite. The compositional evolution of CGM shows a slight increase in Ta/Nb and Mn/Fe in the zones A and B followed by a reverse trend to elevated Nb and Fe in the zone C and, in particular, in the zone D. Complex subsolidus fluid-melt interactions that generated patches and veinlets caused only minor changes in Ta/Nb and slight Mn-enrichment. Tantalum depletion in veins close to jarosite pseudomorphs after pyrite indicates higher mobility of Ta in acidic low-temperature fluids.

Návaznosti

MUNI/A/1653/2016, interní kód MU

Název: Geologické, geodynamické a environmentální procesy při východním okraji Českého masívu (Akronym: Geodyn)

Investor: Masarykova univerzita, Geologické, geodynamické a environmentální procesy při východním okraji Českého masívu, DO R. 2020_Kategorie A - Specifický výzkum - Studentské výzkumné projekty

Citovat

NOVÁK, Milan; Stepan CHLADEK; Pavel UHER a Petr GADAS. Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals. Journal of Geosciences. Praha: Česká geologická společnost, 2018, roč. 63, č. 3, s. 253-263. ISSN 1802-6222. Dostupné z: https://doi.org/10.3190/jgeosci.269.

@article{1579199,
   author = {Novák, Milan and Chladek, Stepan and Uher, Pavel and Gadas, Petr},
   article_location = {Praha},
   article_number = {3},
   doi = {https://doi.org/10.3190/jgeosci.269},
   keywords = {columbite-group minerals; tapiolite; compositional trends; Nb-Ta and Fe-Mn fractionation; granitic pegmatite},
   language = {eng},
   issn = {1802-6222},
   journal = {Journal of Geosciences},
   title = {Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals},
   url = {http://www.jgeosci.org/content/jgeosci.269_novak.pdf},
   volume = {63},
   year = {2018}
}

TY  - JOUR
ID  - 1579199
AU  - Novák, Milan - Chladek, Stepan - Uher, Pavel - Gadas, Petr
PY  - 2018
TI  - Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals
JF  - Journal of Geosciences
VL  - 63
IS  - 3
SP  - 253-263
EP  - 253-263
PB  - Česká geologická společnost
SN  - 18026222
KW  - columbite-group minerals
KW  - tapiolite
KW  - compositional trends
KW  - Nb-Ta and Fe-Mn fractionation
KW  - granitic pegmatite
UR  - http://www.jgeosci.org/content/jgeosci.269_novak.pdf
L2  - http://www.jgeosci.org/content/jgeosci.269_novak.pdf
N2  - The simply zoned Sejby pegmatite of beryl-columbite subtype is enclosed in migmatitized gneisses - country rocks of the southern part of the Central Moldanubian Plutonic Complex, Bohemian Massif, Czech Republic. The columbite-group minerals (CGM) occur mostly in blocky K-feldspar unit. Primary magmatic CGM [columbite-(Fe)-tantalite-(Fe)], show an interesting compositional and textural evolution. Subhomogeneous cores of columbite-(Fe)-tantalite-(Fe) (A) are surrounded by heterogeneous intermediate zones (B) and (C) with irregular to oscillatory zoning and mutually comparable compositions. Zone (B) contains grains of tapiolite-(Fe) and inclusions of pyrite decomposed into a mixture of secondary jarosite-group minerals. In the next zone (C), irregular Mn-enriched patches occur and in the outermost thin zone (D) CGM exhibit fine oscillatory zoning typically developed at crystal terminations. The late, subsolidus CGM include patchy-zoned Mn-enriched columbite-(Fe) and late columbite-(Fe) veinlets both formed at the expense of their magmatic precursors in the zone C; the veinlets are also present in the zone D. Similar but fine patches and veinlets are developed around jarosite pseudomorphs after pyrite. The compositional evolution of CGM shows a slight increase in Ta/Nb and Mn/Fe in the zones A and B followed by a reverse trend to elevated Nb and Fe in the zone C and, in particular, in the zone D. Complex subsolidus fluid-melt interactions that generated patches and veinlets caused only minor changes in Ta/Nb and slight Mn-enrichment. Tantalum depletion in veins close to jarosite pseudomorphs after pyrite indicates higher mobility of Ta in acidic low-temperature fluids.
ER  -

NOVÁK, Milan; Stepan CHLADEK; Pavel UHER a Petr GADAS. Complex magmatic and subsolidus compositional trends of columbite-tantalite in the beryl-columbite Sejby granitic pegmatite, Czech Republic: role of crystal-structural constraints and associated minerals. \textit{Journal of Geosciences}. Praha: Česká geologická společnost, 2018, roč.~63, č.~3, s.~253-263. ISSN~1802-6222. Dostupné z: https://doi.org/10.3190/jgeosci.269.

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