Zirconian-niobian titanite and associated Zr-, Nb-, REE-rich accessory minerals: Products of hydrothermal overprint of leucocratic teschenites (Silesian Unit, Outer Western Carpathians, Czech Republic)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F20%3A73603761" target="_blank" >RIV/61989592:15310/20:73603761 - isvavai.cz</a>

Alternative codes found

RIV/00023272:_____/20:10134839 RIV/00025798:_____/20:00000082

Result on the web

<a href="http://www.geologicacarpathica.com/browse-journal/volumes/71-4/article-952/" target="_blank" >http://www.geologicacarpathica.com/browse-journal/volumes/71-4/article-952/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.31577/GeolCarp.71.4.4" target="_blank" >10.31577/GeolCarp.71.4.4</a>

Result language

angličtina

Original language name

Zirconian-niobian titanite and associated Zr-, Nb-, REE-rich accessory minerals: Products of hydrothermal overprint of leucocratic teschenites (Silesian Unit, Outer Western Carpathians, Czech Republic)

Original language description

Sills of hydrothermally altered alkaline magmatic rock (teschenite) of Lower Cretaceous age at the Čerťák and Řepiště sites in the Silesian Unit (Flysch Belt of the Outer Western Carpathians, Czech Republic) host leucocratic dykes and nests which contain accessory minerals enriched in Zr, Nb and REE: Zr-, Nb-rich titanite, zircon, gittinsite, pyrochlore, monazite, REE-rich apatite, epidote, and vesuvianite. Titanite forms wedge-shaped crystals or irregular aggregates enclosed in the analcime groundmass or overgrowths on Zr-rich ferropargasite and taramite or Zr-rich aegirine–augite to aegirine. Titanite crystals show oscillatory or irregular patchy to sector zoning and contain up to 17.7 wt. % ZrO2 and 19.6 wt. % Nb2O5, and ≤1.1 wt. % REE2O3. High-field-strength elements (HFSE) are incorporated into the structure of the studied titanite predominantly by substitutions: (i) [6]Ti4+ ↔ [6]Zr4+; (ii) [6]Ti4+ + [6]Al3+ ↔ [6]Zr4+ + [6]Fe3+; and (iii) [6]2Ti4+ ↔ [6]Nb5+ + [6](Al, Fe)3+. Magmatic fractional crystallization, high-temperature hydrothermal autometasomatic overprint and low-temperature hydrothermal alterations resulted in the formation of the HFSE-rich mineral assemblages within the leucocratic teschenites. Autometamorphic processes caused by high-temperature hypersaline aqueous solutions (salinity ~50 wt. %, ~390–510 °C), which were released from the HFSE-enriched residual melt, played a major role in the crystallization of Zr-, Nb-, and REE-rich minerals. The mobilization of HFSE could have occurred either by their sequestration into a fluid phase exsolved from the crystallizing melt or by superimposed alteration processes. The distinctive positive Eu anomaly (EuCN/Eu* = 1.85) of leucocratic dykes infers possible mixing of Eu2+-bearing magmatic fluids with more oxidized fluids.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10504 - Mineralogy

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

GEOLOGICA CARPATHICA

ISSN

1335-0552

e-ISSN

—

Volume of the periodical

71

Issue of the periodical within the volume

4

Country of publishing house

SK - SLOVAKIA

Number of pages

18

Pages from-to

343-360

UT code for WoS article

000565769300004

EID of the result in the Scopus database

2-s2.0-85100722089