Earth’s geodynamic evolution constrained by 182W in Archean seawater

Author(s)

Andrea Mundl-Petermeier, Sebastian Viehmann, Jonas Tusch, Michael Bau, Florian Kurzweil, Carsten Münker

Abstract

Radiogenic isotope systems are important geochemical tools to unravel geodynamic processes on Earth. Applied to ancient marine chemical sediments such as banded iron formations, the short-lived

182Hf-

182W isotope system can serve as key instrument to decipher Earth's geodynamic evolution. Here we show high-precision

182W isotope data of the 2.7 Ga old banded iron formation from the Temagami Greenstone Belt, NE Canada, that reveal distinct

182W differences in alternating Si-rich (7.9 ppm enrichment) and Fe-rich (5.3 ppm enrichment) bands reflecting variable flux of W from continental and hydrothermal mantle sources into ambient seawater, respectively. Greater

182W excesses in Si-rich layers relative to associated shales (5.9 ppm enrichment), representing regional upper continental crust composition, suggest that the Si-rich bands record the global rather than the local seawater

182W signature. The distinct intra-band differences highlight the potential of

182W isotope signatures in banded iron formations to simultaneously track the evolution of crust and upper mantle through deep time.

Organisation(s)

Department of Lithospheric Research

External organisation(s)

Universität zu Köln, Jacobs Universität Bremen

Journal

Nature Communications

Volume

13

No. of pages

8

ISSN

2041-1723

DOI

https://doi.org/10.1038/s41467-022-30423-3

Publication date

05-2022

Peer reviewed

Yes

Austrian Fields of Science 2012

105105 Geochemistry

Keywords

ASJC Scopus subject areas

General, General Physics and Astronomy, General Chemistry, General Biochemistry,Genetics and Molecular Biology

Portal url

https://ucrisportal.univie.ac.at/en/publications/ba7404d1-614f-4757-8806-cb809d189035