2012
CONTRASTING ORIGINS OF THE MIXED (NYF plus LCT) SIGNATURE IN GRANITIC PEGMATITES, WITH EXAMPLES FROM THE MOLDANUBIAN ZONE, CZECH REPUBLIC
NOVÁK, Milan; Radek ŠKODA; Petr GADAS; Lukáš KRMÍČEK; Petr ČERNÝ et al.Základní údaje
Originální název
CONTRASTING ORIGINS OF THE MIXED (NYF plus LCT) SIGNATURE IN GRANITIC PEGMATITES, WITH EXAMPLES FROM THE MOLDANUBIAN ZONE, CZECH REPUBLIC
Autoři
Vydání
Canadian Mineralogist, Ottawa, MAC, 2012, 0008-4476
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10500 1.5. Earth and related environmental sciences
Stát vydavatele
Kanada
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 1.180
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/12:00058610
Organizační jednotka
Přírodovědecká fakulta
UT WoS
Klíčová slova anglicky
Li-bearing pegmatites; mixed (NYF plus LCT) signature; origin; contamination; mixing test; Moldanubian Zone; Czech Republic
Změněno: 9. 4. 2013 15:55, Ing. Andrea Mikešková
Anotace
V originále
Two granitic pegmatites with mixed (NYF + LCT) signatures from the Moldanubian Zone, Czech Republic, were examined to determine their origin. On the basis of geological setting, paragenesis, geochemical modeling and chemical composition of rocks and minerals, two contrasting modes of origin were discerned. The Li-bearing (lithium micas + elbaite) Kracovice pegmatite, with "amazonite", samarskite and fergusonite, is the product of the strong fractionation of pegmatite-forming melt derived from the orogenic I-type Trebic pluton. Geological, petrological, compositional and isotopic data from this ultrapotassic melasyenite-melagranite point to mixing of a mantle-derived magma with (leuco) granitic melt from crustal rocks. The granite-pegmatite system of the Trebic pluton and the mainly Li-bearing Kracovice pegmatite are typical examples of the mixed (NYF + LCT) petrogenetic family. The contaminated elbaite-subtype pegmatite Blizna I, Cesky Krumlov Unit, with lithium tourmalines (elbaite, liddicoatite, uvite), primary REE minerals [bastnasite-(Ce), parisite-(Ce), allanite-(Ce)] and Ca(Mg)-rich minerals (diopside, uvite, titanite), gained its mixed signature through a unique pre-emplacement process involving the external contamination with Ca, Mg and REE of an evolved (LCT) pegmatite-forming melt by distal carbonatite-like marbles with an NYF signature. Despite the clearly mixed-signature mineralogy and geochemistry, the Blizna I pegmatite represents a special type of contaminated LCT pegmatite rather than a member of the mixed family.
Návaznosti
| GAP210/10/0743, projekt VaV |
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