Interaction of seawater with (ultra)mafic alkaline rocks-Alternative process for the formation of aegirine

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27350%2F24%3A10254928" target="_blank" >RIV/61989100:27350/24:10254928 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/24:10169056 RIV/61989592:15310/24:73626648

Výsledek na webu

<a href="https://pubs.geoscienceworld.org/ammin/issue/109/3" target="_blank" >https://pubs.geoscienceworld.org/ammin/issue/109/3</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.2138/am-2023-8928" target="_blank" >10.2138/am-2023-8928</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Interaction of seawater with (ultra)mafic alkaline rocks-Alternative process for the formation of aegirine

Popis výsledku v původním jazyce

Submarine mafic and relatively Na-poor alkaline rocks in the Outer Carpathians often contain aegirine, a sodic pyroxene usually found in diferentiated alkaline rocks. Its presence in rocks that are too basic and Na-poor for its conventional magmatic appearance is linked to sodic alteration of submarine alkaline rocks. Aegirine crystals grow on altered rims of diopside, commonly with crystallographic unconformity, suggesting that their growth was related to alteration and that aegirine does not represent a late stage of continuous clinopyroxene crystallization. The U-shaped REE patterns in the studied aegirine lack Eu anomaly, characteristic for aegirine from differentiated alkaline rocks. Therefore, the involvement of chemically more evolved magma is unlikely to have played any role in the formation of aegirine in ijolites and essexites. Formation of aegirine in submarine alkaline rocks may thus represent an alternative process to spilitization. However, this process is strongly limited by the availability of Fe3+ oxidized and mobilized by hydrothermal alteration, which may explain a relative scarcity of aegirine observed in submarine alkaline rocks compared to near-complete albitization of spilites, and its absence in high-MgO rocks (&gt;10 wt%). Due to the blocking effect related to Fe3+ unavailability, ijolites, and essexites do not display significant Na enrichment. We posit that Na incorporated in aegirine was mainly sourced from the zeolitized interstitial glass.

Název v anglickém jazyce

Interaction of seawater with (ultra)mafic alkaline rocks-Alternative process for the formation of aegirine

Popis výsledku anglicky

Submarine mafic and relatively Na-poor alkaline rocks in the Outer Carpathians often contain aegirine, a sodic pyroxene usually found in diferentiated alkaline rocks. Its presence in rocks that are too basic and Na-poor for its conventional magmatic appearance is linked to sodic alteration of submarine alkaline rocks. Aegirine crystals grow on altered rims of diopside, commonly with crystallographic unconformity, suggesting that their growth was related to alteration and that aegirine does not represent a late stage of continuous clinopyroxene crystallization. The U-shaped REE patterns in the studied aegirine lack Eu anomaly, characteristic for aegirine from differentiated alkaline rocks. Therefore, the involvement of chemically more evolved magma is unlikely to have played any role in the formation of aegirine in ijolites and essexites. Formation of aegirine in submarine alkaline rocks may thus represent an alternative process to spilitization. However, this process is strongly limited by the availability of Fe3+ oxidized and mobilized by hydrothermal alteration, which may explain a relative scarcity of aegirine observed in submarine alkaline rocks compared to near-complete albitization of spilites, and its absence in high-MgO rocks (&gt;10 wt%). Due to the blocking effect related to Fe3+ unavailability, ijolites, and essexites do not display significant Na enrichment. We posit that Na incorporated in aegirine was mainly sourced from the zeolitized interstitial glass.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10507 - Volcanology

Projekt

<a href="/cs/project/GA21-30043S" target="_blank" >GA21-30043S: Petrogeneze a vmístění hlubokomořských alkalických bazaltoidů: případ spodnokřídového magmatismu severní Tethydy</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

American Mineralogist

ISSN

0003-004X

e-ISSN

1945-3027

Svazek periodika

109

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

488-501

Kód UT WoS článku

001183294700011

EID výsledku v databázi Scopus

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