TY - JOUR

T1 - Earth’s geodynamic evolution constrained by 182W in Archean seawater

AU - Mundl-Petermeier, A.

AU - Viehmann, S.

AU - Tusch, J.

AU - Bau, M.

AU - Kurzweil, F.

AU - Münker, C.

N1 - Funding information: A.M.-P. acknowledges FWF grant V659-N29 that funded this research. S.V. acknowledges FWF project P34238. J.T. and C.M. acknowledge funding through the European Commission by ERC grant 669666 ‘Infant Earth’. M.B. acknowledges funding from the Deutsche Forschungsgemeinschaft (grant BA-2289/8–1) within the framework of DFG Priority Program 1833 “Building a Habitable Earth”.

PY - 2022/12

Y1 - 2022/12

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85130068875&partnerID=8YFLogxK

U2 - 10.1038/s41467-022-30423-3

DO - 10.1038/s41467-022-30423-3

M3 - Article

C2 - 35577795

AN - SCOPUS:85130068875

VL - 13

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

IS - 1

M1 - 2701

ER -