Details
| Originalsprache | Englisch |
|---|---|
| Aufsatznummer | 577 |
| Fachzeitschrift | Communications Earth and Environment |
| Jahrgang | 6 |
| Ausgabenummer | 1 |
| Frühes Online-Datum | 23 Juli 2025 |
| Publikationsstatus | Veröffentlicht - Dez. 2025 |
Abstract
As a sub-type of micrometeorites, I-type cosmic spherules form by complete melting and oxidation of extraterrestrial Fe, Ni metal particles during their atmospheric entry. All oxygen in the resulting Fe, Ni oxides sources from the Earth’s atmosphere and hence makes them probes for the composition of atmospheric oxygen. When recovered from sedimentary rocks, they allow the reconstruction of the triple oxygen isotope composition of past atmospheric O2, providing quantitative constraints on past CO2 levels or global primary production. Here we establish using fossil I-type cosmic spherules as an archive of Earth’s atmospheric composition with the potential for a unique record of paleo-atmospheric conditions dating back billions of years. We present combined triple oxygen and iron isotope compositions of a collection of fossil I-type cosmic spherules recovered from Phanerozoic sediments. We reconstruct the triple oxygen isotope anomalies of past atmospheric O2 and quantify moderate ancient CO2 levels during the Miocene (~8.5 million years) and late Cretaceous (~87 million years). We also demonstrate this method’s competitive precision for paleo-CO2 determination, despite challenges in finding micrometer-sized unaltered fossil I-type cosmic spherules. Our work indicates that morphologically intact spherules can be isotopically altered by terrestrial processes, underscoring the need for rigorous sample screening.
ASJC Scopus Sachgebiete
- Umweltwissenschaften (insg.)
- Allgemeine Umweltwissenschaft
- Erdkunde und Planetologie (insg.)
- Allgemeine Erdkunde und Planetologie
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in: Communications Earth and Environment, Jahrgang 6, Nr. 1, 577, 12.2025.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Traces of the oxygen isotope composition of ancient air in fossilized cosmic dust
AU - Zahnow, Fabian
AU - Suttle, Martin D.
AU - Lazarov, Marina
AU - Weyer, Stefan
AU - Di Rocco, Tommaso
AU - Folco, Luigi
AU - Pack, Andreas
N1 - Publisher Copyright: © The Author(s) 2025.
PY - 2025/12
Y1 - 2025/12
N2 - As a sub-type of micrometeorites, I-type cosmic spherules form by complete melting and oxidation of extraterrestrial Fe, Ni metal particles during their atmospheric entry. All oxygen in the resulting Fe, Ni oxides sources from the Earth’s atmosphere and hence makes them probes for the composition of atmospheric oxygen. When recovered from sedimentary rocks, they allow the reconstruction of the triple oxygen isotope composition of past atmospheric O2, providing quantitative constraints on past CO2 levels or global primary production. Here we establish using fossil I-type cosmic spherules as an archive of Earth’s atmospheric composition with the potential for a unique record of paleo-atmospheric conditions dating back billions of years. We present combined triple oxygen and iron isotope compositions of a collection of fossil I-type cosmic spherules recovered from Phanerozoic sediments. We reconstruct the triple oxygen isotope anomalies of past atmospheric O2 and quantify moderate ancient CO2 levels during the Miocene (~8.5 million years) and late Cretaceous (~87 million years). We also demonstrate this method’s competitive precision for paleo-CO2 determination, despite challenges in finding micrometer-sized unaltered fossil I-type cosmic spherules. Our work indicates that morphologically intact spherules can be isotopically altered by terrestrial processes, underscoring the need for rigorous sample screening.
AB - As a sub-type of micrometeorites, I-type cosmic spherules form by complete melting and oxidation of extraterrestrial Fe, Ni metal particles during their atmospheric entry. All oxygen in the resulting Fe, Ni oxides sources from the Earth’s atmosphere and hence makes them probes for the composition of atmospheric oxygen. When recovered from sedimentary rocks, they allow the reconstruction of the triple oxygen isotope composition of past atmospheric O2, providing quantitative constraints on past CO2 levels or global primary production. Here we establish using fossil I-type cosmic spherules as an archive of Earth’s atmospheric composition with the potential for a unique record of paleo-atmospheric conditions dating back billions of years. We present combined triple oxygen and iron isotope compositions of a collection of fossil I-type cosmic spherules recovered from Phanerozoic sediments. We reconstruct the triple oxygen isotope anomalies of past atmospheric O2 and quantify moderate ancient CO2 levels during the Miocene (~8.5 million years) and late Cretaceous (~87 million years). We also demonstrate this method’s competitive precision for paleo-CO2 determination, despite challenges in finding micrometer-sized unaltered fossil I-type cosmic spherules. Our work indicates that morphologically intact spherules can be isotopically altered by terrestrial processes, underscoring the need for rigorous sample screening.
UR - http://www.scopus.com/inward/record.url?scp=105011343734&partnerID=8YFLogxK
U2 - 10.1038/s43247-025-02541-5
DO - 10.1038/s43247-025-02541-5
M3 - Article
AN - SCOPUS:105011343734
VL - 6
JO - Communications Earth and Environment
JF - Communications Earth and Environment
IS - 1
M1 - 577
ER -