J 2014

Alpine oxidation of lithium micas in Permian S-type granites (Gemeric unit, Western Carpathians, Slovakia)

PETŘÍK, I., M. ČÍK, M. MIGLIERINI, Tomáš VACULOVIČ, I. DIANIŠKA et. al.

Basic information

Original name

Alpine oxidation of lithium micas in Permian S-type granites (Gemeric unit, Western Carpathians, Slovakia)

Authors

PETŘÍK, I. (703 Slovakia, guarantor), M. ČÍK (703 Slovakia), M. MIGLIERINI (703 Slovakia), Tomáš VACULOVIČ (703 Slovakia, belonging to the institution), I. DIANIŠKA (703 Slovakia) and D. OZDÍN (703 Slovakia)

Edition

Mineralogical Magazine, Middlesex, Mineralogical Society, 2014, 0026-461X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10406 Analytical chemistry

Country of publisher

Czech Republic

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 2.026

RIV identification code

RIV/00216224:14740/14:00079354

Organization unit

Central European Institute of Technology

UT WoS

000344420400003

Keywords in English

lithium micas; zinnwaldite; phengite; Permian granite; oxidation; Alpine metamorphism; Gemeric unit; Western Carpathians; Slovakia

Tags

International impact, Reviewed
Změněno: 18/3/2015 09:41, doc. Mgr. Tomáš Vaculovič, Ph.D.

Abstract

V originále

Lithium micas of the zinnwaldite and phengite-Li-phengite series occur as characteristic minerals in Permian Li-F-(P) granites of the western Gemeric unit (Western Carpathians) accompanied by topaz, tourmaline, Nb, Ta, Ti, Sn oxides and aluminophosphates. The calculated Li2O contents of all the mica analysed, together with Rb2O and Cs2O were confirmed by LA-ICP-MS analyses for all the identified micas. Samples from three localities were investigated: two surficial (Surovec, Vrchsul'ova); and one drill hole (Dlha dolina). Zinnwaldite (polylithionite) occurs in the upper level of the Dlha dolina granitic intrusion and in the nearby shallow satellite body of Surovec. The lower level porphyritic granites contain only siderophyllite. The Vrchsul'ova micas are closer in composition to Li-annite and siderophyllite. Dioctahedral micas are mostly phengites, although zinnwaldite-bearing granites are rich in late-crystallizing Li-phengite, which extensively replaces earlier zinnwaldite. The secondary Li-phengite and phengite are interpreted as products of Alpine metamorphism during Cretaceous burial and subsequent exhumation of the Gemeric unit. Reactions are suggested explaining the formation of Li-phengite by reaction of zinnwaldite with phengite or with muscovite. All mica types were investigated by Mossbauer spectroscopy, which showed high degrees of oxidation (25-50% Fe3+ of total Fe) with the exception of zinnwaldite from Vrchsul'ova, which may have preserved an original, reduced value of 10%. The metamorphic assemblage present permitted calculation of P-T-X conditions: T = 184 degrees C, P = 320 MPa, with oxidation of siderophyllite to phengite + goethite and f(O2) at Delta NN = 4.7, confirming the low-grade conditions of the Alpine metamorphism in agreement with previous estimates.