Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model
The result's identifiers
Result code in 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>
Alternative codes found
RIV/00025798:_____/21:00000049
Result on the web
<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>
Alternative languages
Result language
angličtina
Original language name
Biogeochemical reappraisal of the freshwater–seawater mixing-zone diagenetic model
Original language description
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.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
<a href="/en/project/GJ19-15096Y" target="_blank" >GJ19-15096Y: Microbially induced iron, nitrogen and phosphorus co-recycling and transient decoupling in aqueous ferruginous ecosystems</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Sedimentology
ISSN
0037-0746
e-ISSN
1365-3091
Volume of the periodical
68
Issue of the periodical within the volume
5
Country of publishing house
GB - UNITED KINGDOM
Number of pages
34
Pages from-to
1797-1830
UT code for WoS article
000637480700001
EID of the result in the Scopus database
2-s2.0-85103905527