Marine anoxia as a trigger for the largest Phanerozoic positive carbon isotope excursion: evidence from carbonate barium isotope records

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F22%3A00000232" target="_blank" >RIV/00025798:_____/22:00000232 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60460709:41330/22:89944

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/abs/pii/S0012821X22000577" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S0012821X22000577</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.epsl.2022.117421" target="_blank" >10.1016/j.epsl.2022.117421</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Marine anoxia as a trigger for the largest Phanerozoic positive carbon isotope excursion: evidence from carbonate barium isotope records

Popis výsledku v původním jazyce

The mid-Ludfordian Lau carbon isotope excursion (Lau CIE) represents the largest positive carbon isotope excursion in the Phanerozoic (∼9), coincident with the biodiversity loss of many marine animal clades. Two main explanations for the Lau CIE are enhanced organic carbon burial via increased marine productivity and preservation-driven expansion of anoxia. While these two explanations are not mutually exclusive, the main driver of Lau CIE is yet to be constrained. Here, we resolve this longstanding debate using barium isotopes (delta138Ba) of marine carbonates deposited across the Lau CIE. Our delta138Badata from the Kosov section (Czech Republic) record a large negative excursion in correlation to the positive shift in delta13Ccarb. We suggest that the observed negative shift in delta138Bato values as low as −0.33can be best interpreted as upwelling of isotopically light Ba from deeper waters due to pelagic barite dissolution under euxinic conditions. This hypothesis is consistent with results from barium concentration data as well as the results from the sulfate mass balance modeling that indicates a contraction in the seawater sulfate reservoir, with seawater sulfate concentrations decreasing from several mM ranges before the Lau CIE to less than 100míM during Lau CIE. Taken together, evidence for a strong negative correlation between delta138Baand delta13Ccarbsuggests that shallow water anoxia, rather than enhanced marine productivity, was a primary driver of the Lau CIE that resulted in a notable decrease in the size of seawater sulfate reservoir.

Název v anglickém jazyce

Marine anoxia as a trigger for the largest Phanerozoic positive carbon isotope excursion: evidence from carbonate barium isotope records

Popis výsledku anglicky

The mid-Ludfordian Lau carbon isotope excursion (Lau CIE) represents the largest positive carbon isotope excursion in the Phanerozoic (∼9), coincident with the biodiversity loss of many marine animal clades. Two main explanations for the Lau CIE are enhanced organic carbon burial via increased marine productivity and preservation-driven expansion of anoxia. While these two explanations are not mutually exclusive, the main driver of Lau CIE is yet to be constrained. Here, we resolve this longstanding debate using barium isotopes (delta138Ba) of marine carbonates deposited across the Lau CIE. Our delta138Badata from the Kosov section (Czech Republic) record a large negative excursion in correlation to the positive shift in delta13Ccarb. We suggest that the observed negative shift in delta138Bato values as low as −0.33can be best interpreted as upwelling of isotopically light Ba from deeper waters due to pelagic barite dissolution under euxinic conditions. This hypothesis is consistent with results from barium concentration data as well as the results from the sulfate mass balance modeling that indicates a contraction in the seawater sulfate reservoir, with seawater sulfate concentrations decreasing from several mM ranges before the Lau CIE to less than 100míM during Lau CIE. Taken together, evidence for a strong negative correlation between delta138Baand delta13Ccarbsuggests that shallow water anoxia, rather than enhanced marine productivity, was a primary driver of the Lau CIE that resulted in a notable decrease in the size of seawater sulfate reservoir.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA21-10799S" target="_blank" >GA21-10799S: Vliv prostředí na vzestup a pád nejstarších rostlinných společenstev, která osídlila silurské vulkanické ostrovy Pražské pánve (Česká republika)</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Earth and Planetary Science Letters

ISSN

0012-821X

e-ISSN

—

Svazek periodika

584

Číslo periodika v rámci svazku

Apr : 117421

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

11

Strana od-do

nestránkováno

Kód UT WoS článku

000782123400003

EID výsledku v databázi Scopus

2-s2.0-85126276072