Fluorite-bearing vein mineralization from Bartoušov near Havlíčkův Brod: a complex fluid history related to post-Variscan uplift of the Moldanubian basement (Bohemian Massif, Czech Republic)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F23%3A10136171" target="_blank" >RIV/00023272:_____/23:10136171 - isvavai.cz</a>

Result on the web

<a href="http://www.jgeosci.org/content/jgeosci.379_Dolnicek.pdf" target="_blank" >http://www.jgeosci.org/content/jgeosci.379_Dolnicek.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3190/jgeosci.379" target="_blank" >10.3190/jgeosci.379</a>

Result language

angličtina

Original language name

Fluorite-bearing vein mineralization from Bartoušov near Havlíčkův Brod: a complex fluid history related to post-Variscan uplift of the Moldanubian basement (Bohemian Massif, Czech Republic)

Original language description

A subvertical NW-SE trending fluorite-bearing vein at Bartoušov cut small body of two-mica granites hosted by high-grade metamorphic rocks of the Moldanubian Zone of the Bohemian Massif, in the northern part of the tectonic structure of the Jihlava Graben. The vein mineralization features open-space filling and multiple episodes of mineral precipitation. Early fine-grained quartz containing rare Nb- and W-enriched rutile is overgrown by crystals of late quartz and greenish to violet fluorite, followed by veinlets of dolomite-ankerite and calcite with pyrite and siderite. Quartz and fluorite crystallized from heterogeneous aquo-carbonic fluid with highly variable both bulk density and composition. Early CO2-dominated aquo-carbonic fluids probably represent local retrograde-metamorphic fluids, whose variations in density likely reflect the pressure decrease during uplift of the basement during the Carboniferous. Late N2-dominated low-density aquo-carbonic fluids were trapped at ~135-150 oC and ~60-100 bars. Raman analysis proved minor occurrence of CH4, C2H6, H2, and/or O2 in the N2-rich carbonic fluid. The composition of N2-dominated carbonic fluid cannot be explained by the local basement sources only, but it could be derived from the now eroded immature Permo-Carboniferous sediments of the Jihlava Graben. In this concept, N2, hydrocarbons, and possibly some H2 could have been formed due to thermal alteration of immature organic matter, whereas O2 and rest of H2 were likely formed due to radiolysis of water within bodies of synsedimentary uranium ores present in this sedimentary basin. The infiltration of basinal fluids into basement was allowed due to an extensional tectonic regime. Paragenetically late carbonates originated from low- to moderate-salinity aqueous fluids derived from meteoric water and containing elevated amount of carbon from the oxidized organic matter.

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

10505 - Geology

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

Journal of Geosciences

ISSN

1802-6222

e-ISSN

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Volume of the periodical

68

Issue of the periodical within the volume

4

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

20

Pages from-to

261-280

UT code for WoS article

001198181900002

EID of the result in the Scopus database

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