¹Sutton, S.R.,¹Lanzirotti, A.,¹Newville, M.,^2,3Dyar, M.D.,⁴Delaney, J.
Chemical Geology 531, 119305 Link to Article [DOI: 10.1016/j.chemgeo.2019.119305]
¹U. Chicago, IL, United States
²Planetary Science Institute, AZ, United States
³Mount Holyoke College, MA, United States
⁴Rutgers U., NJ, United States

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

¹Povinec, P.P.,¹Sýkora, I.,²Ferrière, L.,^2,3Koeberl, C.
Journal of Radioanalytical and Nuclear Chemistry 324, 349-357 Link to Article [DOI: 10.1007/s10967-020-07034-7]
¹Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, 84248, Slovakia
²Natural History Museum, Burgring 7, Vienna, 1010, Austria
³Department of Lithospheric Research, University of Vienna, Vienna, 1090, Austria

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

¹Pierre Haenecour,²Christine Floss,³Adrian J. Brearley,^1,4Thomas J. Zega
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13477]
¹Lunar and Planetary Laboratory, The University of Arizona, Tucson, Arizona, 85721‐0092 USA
²Laboratory for Space Sciences and McDonnell Center for Space Sciences, Washington University in St. Louis, St. Louis, Missouri, 63130 USA
³Department of Earth and Planetary Sciences, The University of New Mexico, Albuquerque, New Mexico, 87131 USA
⁴Department of Materials Science and Engineering, The University of Arizona, Tucson, Arizona, 85721‐0012 USA
Published by arrangement with John Wiley & Sons

Our detailed mineralogical, elemental, and isotopic study of the Miller Range (MIL) 07687 meteorite showed that, although this meteorite has affinities to CO chondrites, it also exhibits sufficient differences to warrant classification as an ungrouped carbonaceous chondrite. The most notable feature of MIL 07687 is the presence of two distinct matrix lithologies that result from highly localized aqueous alteration. One of these lithologies is Fe‐rich and exhibits evidence for interaction with water, including the presence of fibrous (dendritic) ferrihydrite. The other lithology, which is Fe‐poor, appears to represent relatively unaltered protolith material. MIL 07687 has presolar grain abundances consistent with those observed in other modestly altered carbonaceous chondrites: the overall abundance of O‐rich presolar grains is 137 ± 3 ppm and the overall abundance of SiC grains is 71 ± 11 ppm. However, there is a large difference in the observed O‐rich and SiC grain number densities between altered and unaltered areas, reflecting partial destruction of presolar grains (both O‐ and C‐rich grains) due to the aqueous alteration experienced by MIL 07687 under highly oxidizing conditions. Detailed coordinated NanoSIMS‐TEM analysis of a large hotspot composed of an isotopically normal core surrounded by a rim composed of ¹⁷O‐rich grains is consistent with either original condensation of the core and surrounding grains in the same parent AGB star, or with grain accretion in the ISM or solar nebula.