Crystal chemistry and origin of epidote-(Sr) in alkaline rocks of the teschenite association (Silesian Unit, Outer Western Carpathians, Czech Republic)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F24%3A10136173" target="_blank" >RIV/00023272:_____/24:10136173 - isvavai.cz</a>

Alternative codes found

RIV/61989592:15310/24:73621687

Result on the web

<a href="https://link.springer.com/article/10.1007/s00710-023-00847-w" target="_blank" >https://link.springer.com/article/10.1007/s00710-023-00847-w</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00710-023-00847-w" target="_blank" >10.1007/s00710-023-00847-w</a>

Result language

angličtina

Original language name

Crystal chemistry and origin of epidote-(Sr) in alkaline rocks of the teschenite association (Silesian Unit, Outer Western Carpathians, Czech Republic)

Original language description

A new occurrence of epidote-(Sr) CaSr(Al2Fe3+)[Si2O7][SiO4]O(OH), Sr-REE-rich epidote and Sr-rich allanite-(Ce) is located in Lower Cretaceous, Sr-rich hydrothermally altered leucocratic dykes penetrating alkaline igneous rocks (teschenites) near the Nový Jičín town (the Silesian Unit, Outer Western Carpathians). The dykes contain phenocrysts of pyroxene, amphibole, biotite, fluorapatite and dominant felsic groundmass consisting mostly of alkali feldspars and zeolites (analcime, natrolite and thomsonite-Ca). Accessory minerals include Ti-rich magnetite, prehnite, chamosite, pyrite, calcite, (OH, F)-rich grossular, epidote-group minerals, HFSE-, REE-rich minerals, Sr-rich baryte and slawsonite. The Sr-rich epidote forms columnar crystals or irregular aggregates which are mostly spatially related to chamosite pseudomorphs; it contains 0.15-0.81 apfu Sr, &lt;0.55 apfu REE; Fe3+/(Fe3+ + Al) = 0.16-0.48. The Sr2+ substitutes Ca2+ in the A2 site by a coupled substitution involving other A2 (REE3+, Th4+) or M (Al3+, Fe3+, Fe2+) cations. The Sr-rich epidote crystallized from hydrothermal solutions, probably at temperatures between ~250-430 oC, during cooling of the host rock. The dykes show higher Sr contents (5680-7830 ppm) and 87Sr/86Sri(120 Ma) ratios (~0.7046-0.7047) compared to host mesocratic teschenites (1310-1470 ppm Sr and ~0.7038-0.7045, respectively). The Sr isotopes indicate origin of most Sr from primary magmatic plagioclase in parent teschenite. Nevertheless, there participated fluids of external origin, derived from the Lower Cretaceous seawater or diagenetic waters related to associated siliciclastic sediments with 87Sr/86Sri(120 Ma) = ~0.7073-0.7083. These more radiogenic sources contributed at least 6-21 % of the bulk Sr budget of the studied Sr-rich epidote-bearing leucocratic dykes.

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

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OECD FORD branch

10504 - Mineralogy

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Mineralogy and Petrology

ISSN

0930-0708

e-ISSN

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Volume of the periodical

118

Issue of the periodical within the volume

1

Country of publishing house

AT - AUSTRIA

Number of pages

16

Pages from-to

55-70

UT code for WoS article

001104829600001

EID of the result in the Scopus database

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