In Earth And Planetary Science Letters for 15 Feb (vol. 676), we have:
Miller, Martin F. Residual mass-independently fractionated oxygen present in solids accreted during planetesimal formation in the early Solar System: potential evidence from… Art 119717 .2025.119717
Oxygen forms oxides, obviously. Because oxides (including water) are strong and hard to break down, that oxygen tends to stick where it was, and acts as a tracer for the chemical history of its host mineral and body. Oxygen has three isotopes (16O, 17O, and 18O), whose levels can be used to discriminate between themselves. Separating the three is no easy task, so they form a “fingerprint”.
In this case, Miller uses the oxygen isotopes of main-group pallasites (stony-iron meteorites) as compared to calcium-aluminum rich inclusions (CAIs) to deduce a history and timeline. The pallasites are from large asteroids, which melted into a separate core (of iron) and mantle (rock); pallasites are widely assumed to be the transition zone between the two. Is there a certain connection between these pallasites, and the wider presolar nebula (the cloud of gas and dust that formed our Solar System)?