Talc metasomatism of a magnesite body in response to a granite intrusion: Application of Sm–Nd dating of metasomatic dolomite

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F24%3A00582405" target="_blank" >RIV/67985831:_____/24:00582405 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0024493724000331?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0024493724000331?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.lithos.2024.107521" target="_blank" >10.1016/j.lithos.2024.107521</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Talc metasomatism of a magnesite body in response to a granite intrusion: Application of Sm–Nd dating of metasomatic dolomite

Popis výsledku v původním jazyce

The deposit Gemerská Poloma is located in the Gemeric Superunit of the Western Carpathians and it is currently mined for talc. Talc formed by metasomatic replacement of magnesite, together with dolomite, quartz, pyrite, and accessory minerals. Leachates of dolomite samples in 2.5 M acetic acid yield a Smsingle bondNd isochron age of 271 ± 7 Ma. This age coincides with the previously published ages of the underlying, evolved granitic rocks (from 265 ± 17 to 257 ± 5 Ma, U–Th–Pb on monazite) and the Usingle bondPb age of uraninite (264 ± 1 Ma) interpreted to form from fluids expelled during granite crystallization. The relationship of metasomatism and the granites is further supported by: (i) increased Li and F concentrations in the leachates from dolomite (when compared to the primary magnesite), (ii) increased total REE concentrations in dolomite (compared to magnesite) and even presence of individual REE minerals (bastnäsite) in the ore body, (iii) chondritic Y/Ho ratios, compatible with a magmatic source, (iv) the presence of skarn bodies directly above the magnesite-talc ore deposit, and (v) previously inferred low pressure of talc metasomatism, typical for contact metamorphism in shallow crustal levels. The positive europium anomalies argue for the metasomatism by the action of high-temperature (> 250 °C) hydrothermal fluids that progressively cooled below 250 °C. Thus, the observed talc metasomatism was triggered by the intrusion of the Permian granitic rocks. The Alpine processes tectonically modified the ore body, caused recrystallization and folding of the pre-existing talc and formation of new talc, and obliterated much of the evidence of the earlier processes.

Název v anglickém jazyce

Talc metasomatism of a magnesite body in response to a granite intrusion: Application of Sm–Nd dating of metasomatic dolomite

Popis výsledku anglicky

The deposit Gemerská Poloma is located in the Gemeric Superunit of the Western Carpathians and it is currently mined for talc. Talc formed by metasomatic replacement of magnesite, together with dolomite, quartz, pyrite, and accessory minerals. Leachates of dolomite samples in 2.5 M acetic acid yield a Smsingle bondNd isochron age of 271 ± 7 Ma. This age coincides with the previously published ages of the underlying, evolved granitic rocks (from 265 ± 17 to 257 ± 5 Ma, U–Th–Pb on monazite) and the Usingle bondPb age of uraninite (264 ± 1 Ma) interpreted to form from fluids expelled during granite crystallization. The relationship of metasomatism and the granites is further supported by: (i) increased Li and F concentrations in the leachates from dolomite (when compared to the primary magnesite), (ii) increased total REE concentrations in dolomite (compared to magnesite) and even presence of individual REE minerals (bastnäsite) in the ore body, (iii) chondritic Y/Ho ratios, compatible with a magmatic source, (iv) the presence of skarn bodies directly above the magnesite-talc ore deposit, and (v) previously inferred low pressure of talc metasomatism, typical for contact metamorphism in shallow crustal levels. The positive europium anomalies argue for the metasomatism by the action of high-temperature (> 250 °C) hydrothermal fluids that progressively cooled below 250 °C. Thus, the observed talc metasomatism was triggered by the intrusion of the Permian granitic rocks. The Alpine processes tectonically modified the ore body, caused recrystallization and folding of the pre-existing talc and formation of new talc, and obliterated much of the evidence of the earlier processes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Lithos

ISSN

0024-4937

e-ISSN

1872-6143

Svazek periodika

470-471

Číslo periodika v rámci svazku

April

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

107521

Kód UT WoS článku

001177704800001

EID výsledku v databázi Scopus

2-s2.0-85183985425