Geochemical constraints on the origin of phonolites from the Lužické hory Mts., Ohře (Eger) Rift, Bohemian Massif

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F25%3A00642204" target="_blank" >RIV/67985831:_____/25:00642204 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61389005:_____/25:00642204 RIV/00216224:14310/25:00143450 RIV/00216208:11310/25:10511044

Výsledek na webu

<a href="https://geologicacarpathica.com/browse/archive/?journal_article_no=41176" target="_blank" >https://geologicacarpathica.com/browse/archive/?journal_article_no=41176</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.31577/GeolCarp.2025.20" target="_blank" >10.31577/GeolCarp.2025.20</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Geochemical constraints on the origin of phonolites from the Lužické hory Mts., Ohře (Eger) Rift, Bohemian Massif

Popis výsledku v původním jazyce

Geochemical and petrological data are reported for phonolites from the Lužické hory Mts. in the northeastern part of the Ohře (Eger) Rift near the junction with the Lusatian Fault. The rocks are collectively enriched in incompatible trace elements such as Rb, REEs, Zr, Hf, U, Th, Nb, Ta (concentrated mainly in hainite, Nb-rich titanite and aegirine) and volatile components such as F and Cl. On the other hand, the phonolites are significantly depleted in Ti and P and partly also in Sr and Ba contents. The K–Ar dating provided scattered ages in the range from 34 to 27 Ma. Two geochemically different phonolite types were recognized: (i) type A (higher Sr>90 ppm, Ba>130 ppm) having initial 87Sr/86Sr = 0.7032–0.7094 and εNd=2.9–3.4, similar to those phonolites that are predominant in the nearby České středohoří Mts., and (ii) prevailing type B with lower contents of Sr<20 ppm and Ba<60 characterized by a decoupled Sr–Nd systematics (initial 87Sr/86Sr ratios up to ~0.714) at narrow εNd of 3.2–3.8. Yet, both phonolite types exhibit relatively restricted variations in initial 206Pb/204Pb (19.2–19.5), 207Pb/204Pb (15.61–15.66) and 208Pb/204Pb (39.07–39.30), indicating their derivation from a similar metasomatically enriched mantle source. The observed geochemical characteristics of the studied phonolites can be best explained by (i) variable degree of clinopyroxene and feldspar fractional crystallization from primary basanitic magma, (ii) degree of assimilation-fractional crystallization (AFC) processes during the magma ascent, and/or (iii) late-magmatic to post-magmatic hydrothermal processes related to selective enrichment of some incompatible elements.

Název v anglickém jazyce

Geochemical constraints on the origin of phonolites from the Lužické hory Mts., Ohře (Eger) Rift, Bohemian Massif

Popis výsledku anglicky

Geochemical and petrological data are reported for phonolites from the Lužické hory Mts. in the northeastern part of the Ohře (Eger) Rift near the junction with the Lusatian Fault. The rocks are collectively enriched in incompatible trace elements such as Rb, REEs, Zr, Hf, U, Th, Nb, Ta (concentrated mainly in hainite, Nb-rich titanite and aegirine) and volatile components such as F and Cl. On the other hand, the phonolites are significantly depleted in Ti and P and partly also in Sr and Ba contents. The K–Ar dating provided scattered ages in the range from 34 to 27 Ma. Two geochemically different phonolite types were recognized: (i) type A (higher Sr>90 ppm, Ba>130 ppm) having initial 87Sr/86Sr = 0.7032–0.7094 and εNd=2.9–3.4, similar to those phonolites that are predominant in the nearby České středohoří Mts., and (ii) prevailing type B with lower contents of Sr<20 ppm and Ba<60 characterized by a decoupled Sr–Nd systematics (initial 87Sr/86Sr ratios up to ~0.714) at narrow εNd of 3.2–3.8. Yet, both phonolite types exhibit relatively restricted variations in initial 206Pb/204Pb (19.2–19.5), 207Pb/204Pb (15.61–15.66) and 208Pb/204Pb (39.07–39.30), indicating their derivation from a similar metasomatically enriched mantle source. The observed geochemical characteristics of the studied phonolites can be best explained by (i) variable degree of clinopyroxene and feldspar fractional crystallization from primary basanitic magma, (ii) degree of assimilation-fractional crystallization (AFC) processes during the magma ascent, and/or (iii) late-magmatic to post-magmatic hydrothermal processes related to selective enrichment of some incompatible elements.

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

2025

Kód důvěrnosti údajů

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

Název periodika

Geologica Carpathica

ISSN

1335-0552

e-ISSN

1336-8052

Svazek periodika

76

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

SK - Slovenská republika

Počet stran výsledku

20

Strana od-do

369-388

Kód UT WoS článku

001629632500004

EID výsledku v databázi Scopus

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