Iron isotope fractionation during silicate‑carbonatite liquid immiscibility processes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F25%3A00618118" target="_blank" >RIV/67985831:_____/25:00618118 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/25:10169520 RIV/00216224:14310/25:00141866 RIV/00216305:26110/26:0199942

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0009254125001226?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0009254125001226?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2025.122732" target="_blank" >10.1016/j.chemgeo.2025.122732</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Iron isotope fractionation during silicate‑carbonatite liquid immiscibility processes

Popis výsledku v původním jazyce

Liquid immiscibility is one of the viable genetic models to generate carbonatites. Experimental studies have demonstrated that lighter Fe isotopes are enriched in carbonatite melts, whereas heavier Fe isotopes preferentially enter silicate melts during liquid immiscibility. However, this observation has not been substantiated by natural samples, and the mechanism behind Fe isotope fractionation during silicate–carbonatite immiscibility remains unclear. Here, we present high-precision Fe isotope data, combined with petrography, whole-rock elemental and Srsingle bondNd isotopic compositions, for ultramafic lamprophyres (UML) and carbonatites from the Alnö complex in central Sweden, to elucidate the Fe isotope fractionation during silicate–carbonatite immiscibility processes. The presence of various carbonate spherules in UML, coupled with enrichments in Sr and Ba and depletion in high field strength elements in carbonatites, as well as their overlapping Srsingle bondNd isotope compositions, supports a petrogenetic relationship involving liquid immiscibility between the UML and carbonatites. The mean δ57Fe of UML (0.16 ± 0.08 ‰) is higher than that of carbonatites (0.03 ± 0.04 ‰), with ∆57Fesil−carb of 0.13 ‰ (± 0.05, 2SD). By excluding the effects of low temperature alteration and magmatic processes, we conclude that silicate–carbonatite immiscibility imparts significant Fe isotope fractionation. This fractionation may be influenced by different Fe bond strengths provided by the distinct polymer networks of silicate and carbonatite melts, as well as the varying degrees of Fe enrichment in minerals and melts. This leads to light Fe isotopes being preferentially enriched in the carbonate melt, while heavy Fe isotopes become enriched in the coexisting silicate melt.

Název v anglickém jazyce

Iron isotope fractionation during silicate‑carbonatite liquid immiscibility processes

Popis výsledku anglicky

Liquid immiscibility is one of the viable genetic models to generate carbonatites. Experimental studies have demonstrated that lighter Fe isotopes are enriched in carbonatite melts, whereas heavier Fe isotopes preferentially enter silicate melts during liquid immiscibility. However, this observation has not been substantiated by natural samples, and the mechanism behind Fe isotope fractionation during silicate–carbonatite immiscibility remains unclear. Here, we present high-precision Fe isotope data, combined with petrography, whole-rock elemental and Srsingle bondNd isotopic compositions, for ultramafic lamprophyres (UML) and carbonatites from the Alnö complex in central Sweden, to elucidate the Fe isotope fractionation during silicate–carbonatite immiscibility processes. The presence of various carbonate spherules in UML, coupled with enrichments in Sr and Ba and depletion in high field strength elements in carbonatites, as well as their overlapping Srsingle bondNd isotope compositions, supports a petrogenetic relationship involving liquid immiscibility between the UML and carbonatites. The mean δ57Fe of UML (0.16 ± 0.08 ‰) is higher than that of carbonatites (0.03 ± 0.04 ‰), with ∆57Fesil−carb of 0.13 ‰ (± 0.05, 2SD). By excluding the effects of low temperature alteration and magmatic processes, we conclude that silicate–carbonatite immiscibility imparts significant Fe isotope fractionation. This fractionation may be influenced by different Fe bond strengths provided by the distinct polymer networks of silicate and carbonatite melts, as well as the varying degrees of Fe enrichment in minerals and melts. This leads to light Fe isotopes being preferentially enriched in the carbonate melt, while heavy Fe isotopes become enriched in the coexisting silicate melt.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GX19-29124X" target="_blank" >GX19-29124X: VÝVOJ STAVEB A GEOCHEMICKÉ SIGNATURY KARBONATITŮ V ČASE: VÝZNAM MOBILITY A KONCENTRACE KRITICKÝCH KOVŮ</a><br>

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

Chemical Geology

ISSN

0009-2541

e-ISSN

1872-6836

Svazek periodika

681

Číslo periodika v rámci svazku

May

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

13

Strana od-do

122732

Kód UT WoS článku

001451126300001

EID výsledku v databázi Scopus

2-s2.0-105000128488