Redox geochemistry of the red ‘orthoceratite limestone’ of Baltoscandia: Possible linkage to mid-Ordovician palaeoceanographic changes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000085" target="_blank" >RIV/00025798:_____/21:00000085 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985831:_____/21:00542527 RIV/00216224:14310/21:00119061 RIV/61989592:15310/21:73610768

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0037073821000865" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0037073821000865</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.sedgeo.2021.105934" target="_blank" >10.1016/j.sedgeo.2021.105934</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Redox geochemistry of the red ‘orthoceratite limestone’ of Baltoscandia: Possible linkage to mid-Ordovician palaeoceanographic changes

Popis výsledku v původním jazyce

The orthoceratite limestone of the Ordovician epicontinental sea of Baltoscandia is one of the oldest Phanerozoicexamples of pelagic marine red beds (MRBs). Being enriched in authigenic haematite, MRBs are considered to besensitive palaeoceanographic redox indicators. In this paper, the origin of the reddening of the Ordovician MRBsand its timing and redox conditions were addressed at two sections, and in a drill core in the Kinnekulle area,Sweden, through the application of diffuse reflectance spectroscopy, sedimentary petrology (microfacies andelectron microprobe), bulk-rock and in-situ element geochemistry (laser-ablation ICP-MS) and molybdenumstable isotope systematics. Enrichment in haematite (up to ~0.05 wtprocent) occurred during very early diagenesisunder low sedimentation rates (~5 mm/kyr), which is comparable to several examples of Phanerozoic MRBs.The reddening was associated with the mm-scale, in-situ mobility of Fe, Mn, As, Mo and U, due to Fe–Mnredox cycling between primary and secondary minerals and pore water under oxic and suboxic to anoxic conditions; it was not related to significant changes in seawater chemistry. Stratigraphic red-to-grey transitions likelycoincided with two mid-Darriwilian global regressions (the so-called Täljsten and at the base of the GullhögenFormation), likely due to the effects of changing sedimentation rates and sub-bottom redox potentials. The Ordovician MRBs coincided with a positive delta13C excursion during the middle Darriwilian, which is different to MRBexamples cited from the Devonian to the Cretaceous age, which frequently coincide with shifts to lower valuesof delta13C. Although MRBs are believed to show a time-specific occurrence in greenhouse or transitionalgreenhouse-to-icehouse climatic modes by several authors, our study suggests that causal links between MRBsand global carbon cycle remain unclear

Název v anglickém jazyce

Redox geochemistry of the red ‘orthoceratite limestone’ of Baltoscandia: Possible linkage to mid-Ordovician palaeoceanographic changes

Popis výsledku anglicky

The orthoceratite limestone of the Ordovician epicontinental sea of Baltoscandia is one of the oldest Phanerozoicexamples of pelagic marine red beds (MRBs). Being enriched in authigenic haematite, MRBs are considered to besensitive palaeoceanographic redox indicators. In this paper, the origin of the reddening of the Ordovician MRBsand its timing and redox conditions were addressed at two sections, and in a drill core in the Kinnekulle area,Sweden, through the application of diffuse reflectance spectroscopy, sedimentary petrology (microfacies andelectron microprobe), bulk-rock and in-situ element geochemistry (laser-ablation ICP-MS) and molybdenumstable isotope systematics. Enrichment in haematite (up to ~0.05 wtprocent) occurred during very early diagenesisunder low sedimentation rates (~5 mm/kyr), which is comparable to several examples of Phanerozoic MRBs.The reddening was associated with the mm-scale, in-situ mobility of Fe, Mn, As, Mo and U, due to Fe–Mnredox cycling between primary and secondary minerals and pore water under oxic and suboxic to anoxic conditions; it was not related to significant changes in seawater chemistry. Stratigraphic red-to-grey transitions likelycoincided with two mid-Darriwilian global regressions (the so-called Täljsten and at the base of the GullhögenFormation), likely due to the effects of changing sedimentation rates and sub-bottom redox potentials. The Ordovician MRBs coincided with a positive delta13C excursion during the middle Darriwilian, which is different to MRBexamples cited from the Devonian to the Cretaceous age, which frequently coincide with shifts to lower valuesof delta13C. Although MRBs are believed to show a time-specific occurrence in greenhouse or transitionalgreenhouse-to-icehouse climatic modes by several authors, our study suggests that causal links between MRBsand global carbon cycle remain unclear

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA19-17435S" target="_blank" >GA19-17435S: Paleoklimatologický význam paleozoických červených pelagických karbonátů: časově specifické facie nebo produkty mikrobiální aktivity?</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

Sedimentary Geology

ISSN

0037-0738

e-ISSN

1879-0968

Svazek periodika

420

Číslo periodika v rámci svazku

July : 105934

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

16

Strana od-do

nestránkováno

Kód UT WoS článku

000659165600010

EID výsledku v databázi Scopus

2-s2.0-85106313858