Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F21%3A00545490" target="_blank" >RIV/60077344:_____/21:00545490 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/21:00000049

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/10.1111/sed.12849" target="_blank" >https://onlinelibrary.wiley.com/doi/10.1111/sed.12849</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/sed.12849" target="_blank" >10.1111/sed.12849</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model

Popis výsledku v původním jazyce

First proposed nearly half a century ago, the mixing-zone model of dolomitization enjoyed a brief stay in the limelight before falling out of favour. Despite extended past criticism, arguments that build on its current validity are presented and discussed. The coastal mixing zone can be seen as an aquifer system exhibiting marked physicochemical gradients, reflective of the admixture of low salinity freshwater and seawater sources with variable redox potentials. This perspective requires a more holistic look at the mixing zone, not only as a gradient of major element concentrations, but also as the locus of enhanced subsurface redox sensitive reactions that occur at the pore-space scale within a moveable diagenetic front. Combined genomic and isotopic data indicate that an active subsurface biosphere thrives in the mixing zone. This could facilitate Mg2+ dehydration, generate alkalinity, consume protons and mobilize potentially catalyzing ions (i.e. Mn and Zn), which are all low temperature factors thought to promote dolomite formation from soluble precursors. In the updated model, the advective mix of fluids with contrasting composition modulate a range of biogeochemically induced mineral dissolution and reprecipitation reactions. Biotic and abiotic interactions between these fluids affect carbonate equilibrium and result in dissolution of soluble aragonitic and calcitic phases, while dolomite precipitates (as cement) and neomorphic replacement. The secondary dolomite often exhibits compositional heterogeneity and contentious δ18O signatures indicative of re-equilibration. The role of manganese, zinc, intermediate sulphur species and ammonia are far from being fully understood, nor is their fingerprint in ancient deposits. Application of in situ spectroscopic imaging techniques, clumped and metal isotope analyses, as well as a more extended use of traditional approaches, such as sulphur isotopes, are poised to open many opportunities to further explore the biogeochemistry of this diagenetic environment and how it relates to platform dolomitization.

Název v anglickém jazyce

Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model

Popis výsledku anglicky

First proposed nearly half a century ago, the mixing-zone model of dolomitization enjoyed a brief stay in the limelight before falling out of favour. Despite extended past criticism, arguments that build on its current validity are presented and discussed. The coastal mixing zone can be seen as an aquifer system exhibiting marked physicochemical gradients, reflective of the admixture of low salinity freshwater and seawater sources with variable redox potentials. This perspective requires a more holistic look at the mixing zone, not only as a gradient of major element concentrations, but also as the locus of enhanced subsurface redox sensitive reactions that occur at the pore-space scale within a moveable diagenetic front. Combined genomic and isotopic data indicate that an active subsurface biosphere thrives in the mixing zone. This could facilitate Mg2+ dehydration, generate alkalinity, consume protons and mobilize potentially catalyzing ions (i.e. Mn and Zn), which are all low temperature factors thought to promote dolomite formation from soluble precursors. In the updated model, the advective mix of fluids with contrasting composition modulate a range of biogeochemically induced mineral dissolution and reprecipitation reactions. Biotic and abiotic interactions between these fluids affect carbonate equilibrium and result in dissolution of soluble aragonitic and calcitic phases, while dolomite precipitates (as cement) and neomorphic replacement. The secondary dolomite often exhibits compositional heterogeneity and contentious δ18O signatures indicative of re-equilibration. The role of manganese, zinc, intermediate sulphur species and ammonia are far from being fully understood, nor is their fingerprint in ancient deposits. Application of in situ spectroscopic imaging techniques, clumped and metal isotope analyses, as well as a more extended use of traditional approaches, such as sulphur isotopes, are poised to open many opportunities to further explore the biogeochemistry of this diagenetic environment and how it relates to platform dolomitization.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

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

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Sedimentology

ISSN

0037-0746

e-ISSN

1365-3091

Svazek periodika

68

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

34

Strana od-do

1797-1830

Kód UT WoS článku

000637480700001

EID výsledku v databázi Scopus

2-s2.0-85103905527