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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10507 - Volcanology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

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

Name of the periodical

Earth and Planetary Science Letters

ISSN

0012-821X

e-ISSN

—

Volume of the periodical

498

Issue of the periodical within the volume

15 September

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

12

Pages from-to

140-151

UT code for WoS article

000442060600013

EID of the result in the Scopus database

2-s2.0-85049526684