Chromium isotope fractionation between modern seawater and biogenic carbonates from the Great Barrier Reef, Australia: Implications for the paleo-seawater δ53Cr reconstruction

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F18%3A00496023" target="_blank" >RIV/67985831:_____/18:00496023 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.epsl.2018.06.032" target="_blank" >http://dx.doi.org/10.1016/j.epsl.2018.06.032</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.epsl.2018.06.032" target="_blank" >10.1016/j.epsl.2018.06.032</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Chromium isotope fractionation between modern seawater and biogenic carbonates from the Great Barrier Reef, Australia: Implications for the paleo-seawater δ53Cr reconstruction

Popis výsledku v původním jazyce

This study investigates chromium isotope variations (delta53Cr) and REE patterns in present-day biogenic carbonates and ocean waters from Lady Elliot Island (LEI) located in the southern Great Barrier Reef (GBR), Australia, which is one of the world's largest carbonate-producing shelf ecosystems. Our results from carbonates collected at LEI revealed a systematic and statistically significant correlation (r2 = 0.83, p < 0.05) between delta53Cr and cerium anomaly (Ce/Ce*) data in molluscan shells (i.e., gastropods). This implies a redox-controlled incorporation of Cr from seawater into a shell during mineralization mediated by the organism. In particular, shells with higher delta53Cr values, which approach the Cr isotope composition of local seawater, tend to be associated with more negative Ce/Ce*. Importantly, the intercept of the above delta53Cr vs. Ce/Ce* correlation points to the Cr isotope composition of local ocean water, which has an average delta53Cr of + 0.82 ± 0.13. Interestingly, the only calcifying organism from LEI that yielded identical delta53Cr vs. Ce/Ce* values as those in ambient ocean water was a microbial calcitic carbonate produced by red coralline algae (Lithothamnion sp.). This organism thus seems to incorporate Cr isotopes and REE from seawater without additional biological discrimination and/or isotope fractionation effects. Our compilation of delta53Cr data from recent marine biogenic carbonates originating from the main oceanic confirms that marine carbonates tend to be systematically enriched in light Cr isotopes relative to local ocean waters. Trace element constraints, however, indicate that some of these shifts to lower delta53Cr values (i.e., approaching -0.1 per mil) are related to a presence of lithogenic Cr in the shells, causing a diagenetic overprint of the primary marine delta53Cr signal.

Název v anglickém jazyce

Chromium isotope fractionation between modern seawater and biogenic carbonates from the Great Barrier Reef, Australia: Implications for the paleo-seawater δ53Cr reconstruction

Popis výsledku anglicky

This study investigates chromium isotope variations (delta53Cr) and REE patterns in present-day biogenic carbonates and ocean waters from Lady Elliot Island (LEI) located in the southern Great Barrier Reef (GBR), Australia, which is one of the world's largest carbonate-producing shelf ecosystems. Our results from carbonates collected at LEI revealed a systematic and statistically significant correlation (r2 = 0.83, p < 0.05) between delta53Cr and cerium anomaly (Ce/Ce*) data in molluscan shells (i.e., gastropods). This implies a redox-controlled incorporation of Cr from seawater into a shell during mineralization mediated by the organism. In particular, shells with higher delta53Cr values, which approach the Cr isotope composition of local seawater, tend to be associated with more negative Ce/Ce*. Importantly, the intercept of the above delta53Cr vs. Ce/Ce* correlation points to the Cr isotope composition of local ocean water, which has an average delta53Cr of + 0.82 ± 0.13. Interestingly, the only calcifying organism from LEI that yielded identical delta53Cr vs. Ce/Ce* values as those in ambient ocean water was a microbial calcitic carbonate produced by red coralline algae (Lithothamnion sp.). This organism thus seems to incorporate Cr isotopes and REE from seawater without additional biological discrimination and/or isotope fractionation effects. Our compilation of delta53Cr data from recent marine biogenic carbonates originating from the main oceanic confirms that marine carbonates tend to be systematically enriched in light Cr isotopes relative to local ocean waters. Trace element constraints, however, indicate that some of these shifts to lower delta53Cr values (i.e., approaching -0.1 per mil) are related to a presence of lithogenic Cr in the shells, causing a diagenetic overprint of the primary marine delta53Cr signal.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

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

498

Číslo periodika v rámci svazku

15 September

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

140-151

Kód UT WoS článku

000442060600013

EID výsledku v databázi Scopus

2-s2.0-85049526684