¹Morten Smelror
Review of Palaeobotany and Palynology, 344, 105439
Open Access Link to Article [DOI: 10.1016/j.revpalbo.2025.105439]
¹Geological Survey of Norway, Trondheim, Norway

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Kanako Yoshihara, ²Hiroshi Isobe
Journal of Mineralogical and Petrological Sciences (in Press)
Open Acces Link to Article [DOI: 10.2465/jmps.250311]
¹Graduate School Science and Technology, Kumamoto University, Kumamoto, 860–8555, Japan
²Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860–8555, Japan

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Gerardo Dominguez, ¹Caroline Caplan, ¹Lauren Tafla, ¹Joshua Lucas, ²Ming-Chang Liu, ²Kevin McKeegan, ³Jeff Gillis
Proceedings of the National Academy of Sciences, 123, e2610806123
Open Access Link to Article [DOI: 10.1073/pnas.2610806123]
¹Department of Physics, California State University, San Marcos, CA 92096-0001
²Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095-1567
³Department of Physics, Washington University of St. Louis, St. Louis, MO 63130

Mass-independent isotope fractionation (MIF) of oxygen provides key insights into atmospheric chemistry and the origin of isotopic anomalies in planetary materials. To date, MIF has been primarily associated with gas-phase processes involving symmetry-dependent reaction pathways, most notably ozone formation. Whether analogous effects can arise in condensed phases or at interfaces remains an open question. Here we report laboratory experiments demonstrating that energetic particle irradiation of icy oxide surfaces produces mass-independent oxygen isotope fractionation at temperatures as low as 10 K. Electron irradiation of SiO₂ and Al₂O₃ substrates in the presence of H₂O ice results in measurable shifts in Δ¹⁷O in the underlying solids. The resulting three-isotope relationships include slope-1-like behavior in SiO₂ and Al₂O₃ and distinct, substrate-dependent trends in Al₂O₃, indicating that irradiation-induced defect formation and interfacial chemistry govern the isotope effects. The magnitude of the observed anomalies demonstrates that irradiation-driven processes can generate substantial oxygen isotope heterogeneity in condensed phases. These results identify a previously unrecognized class of MIF and provide a quantitative framework for interpreting oxygen isotope signatures in radiation-processed environments, including interstellar grains and early solar system materials.

^1,2Yang Liu et al. (>10)
Science (in Press) Link to Article [DOI: 10.1126/science.adz5646]
¹Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
²Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA, USA

Reprinted with permission fromm AAAS

Martian meteorites provide a record of the planet’s geological history. However, most are geologically young samples that are not representative of Mars’ surface, which is dominated by ancient rocks. We describe the Martian meteorite Teghaza 001 (Teg 001), a slowly cooled igneous rock that formed at least 4.1 billion years ago. Its composition, mineralogy, and texture are distinct from other Martian meteorites. We determine that Teg 001 is a sample of ancient crust, which formed from a geochemically distinct mantle source with primordial composition. The presence of aqueously altered minerals, combined with bulk and mineral-specific oxygen isotope measurements, indicate that Teg 001 experienced reactions with fluids enriched in 18O, before ejection into space by an impact.