Redox dynamics and metal cycling in the carbonate-buffered sediment–water interface of the ferruginous and sulfatic Lake Medard, Czech Republic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F25%3A00638660" target="_blank" >RIV/60077344:_____/25:00638660 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60076658:12310/25:43910785 RIV/00025798:_____/25:10169514

Výsledek na webu

<a href="https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/95/4/707/653835/Redox-dynamics-and-metal-cycling-in-the-carbonate?redirectedFrom=fulltext" target="_blank" >https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/95/4/707/653835/Redox-dynamics-and-metal-cycling-in-the-carbonate?redirectedFrom=fulltext</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.2110/jsr.2024.155" target="_blank" >10.2110/jsr.2024.155</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Redox dynamics and metal cycling in the carbonate-buffered sediment–water interface of the ferruginous and sulfatic Lake Medard, Czech Republic

Popis výsledku v původním jazyce

Lake Medard (LM), a post-mining lake in the Czech Republic with stratified, sulfate- and iron-rich bottom waters, serves as a natural laboratory to study sediment–water-interface (SWI) dynamics where steep aqueous redox gradients are present. This study investigates the interplay of redox conditions, microbial activity, and sedimentary processes, revealing that short-term Eh fluctuations (80–100 mV) in the bottom water significantly mobilize rare earth elements (REE) and influence the partitioning of other redox-sensitive elements such as vanadium (V) and arsenic (As) from reactive iron (Fe)- and manganese (Mn)-oxyhydroxides during early diagenesis. While carbonate phases like siderite primarily retain their REE signatures, they can incorporate REE released during these redox shifts. Spectroscopic analyses confirms the presence of FeOOH polymorphs (goethite and lepidocrocite) in organo-mineral aggregates in the upper sediments. Sequential extractions shows that under stronger reducing conditions (Eh ≈ –190 mV), As predominantly associates with carbonates, shifting to Fe(III)-oxyhydroxides at higher Eh (≈ –80 mV). Isotope analyses (d13C) indicate that the bulk sediment carbonate is detrital, sourced from Miocene strata. Authigenic pyrite in LM sediments exhibits d34Spy values (–35.1 to –23.0%), reflecting microbial sulfate reduction. However, the accumulation of the byproduct sulfide, and thus pyrite stabilization, is limited by the low availability of labile organic substrates and the reoxidation of sulfide by Fe(III)-oxyhydroxides. These findings highlight the sensitivity of geochemical signals in sediments to subtle redox shifts and improve our interpretation of ancient deposits formed under dynamic water column redox conditions.

Název v anglickém jazyce

Redox dynamics and metal cycling in the carbonate-buffered sediment–water interface of the ferruginous and sulfatic Lake Medard, Czech Republic

Popis výsledku anglicky

Lake Medard (LM), a post-mining lake in the Czech Republic with stratified, sulfate- and iron-rich bottom waters, serves as a natural laboratory to study sediment–water-interface (SWI) dynamics where steep aqueous redox gradients are present. This study investigates the interplay of redox conditions, microbial activity, and sedimentary processes, revealing that short-term Eh fluctuations (80–100 mV) in the bottom water significantly mobilize rare earth elements (REE) and influence the partitioning of other redox-sensitive elements such as vanadium (V) and arsenic (As) from reactive iron (Fe)- and manganese (Mn)-oxyhydroxides during early diagenesis. While carbonate phases like siderite primarily retain their REE signatures, they can incorporate REE released during these redox shifts. Spectroscopic analyses confirms the presence of FeOOH polymorphs (goethite and lepidocrocite) in organo-mineral aggregates in the upper sediments. Sequential extractions shows that under stronger reducing conditions (Eh ≈ –190 mV), As predominantly associates with carbonates, shifting to Fe(III)-oxyhydroxides at higher Eh (≈ –80 mV). Isotope analyses (d13C) indicate that the bulk sediment carbonate is detrital, sourced from Miocene strata. Authigenic pyrite in LM sediments exhibits d34Spy values (–35.1 to –23.0%), reflecting microbial sulfate reduction. However, the accumulation of the byproduct sulfide, and thus pyrite stabilization, is limited by the low availability of labile organic substrates and the reoxidation of sulfide by Fe(III)-oxyhydroxides. These findings highlight the sensitivity of geochemical signals in sediments to subtle redox shifts and improve our interpretation of ancient deposits formed under dynamic water column redox conditions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10511 - Environmental sciences (social aspects to be 5.7)

Projekt

<a href="/cs/project/GJ19-15096Y" target="_blank" >GJ19-15096Y: Souběžné mikrobiálně řízené cykly železa, dusíku a fosforu a jejich přechodové oddělení v vodních ekosystémech bohatých na redukované železo</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

Journal of Sedimentary Research

ISSN

1527-1404

e-ISSN

1938-3681

Svazek periodika

95

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

707-722

Kód UT WoS článku

001666225000002

EID výsledku v databázi Scopus

2-s2.0-105013135169