@article{fe2a7b9b4e344978b1f5854f87662674,
title = "Uniform initial 10Be/9Be inferred from refractory inclusions in CV3, CO3, CR2, and CH/CB chondrites",
abstract = "Short-lived radionuclides (SLRs) once present in the solar nebula can be used as probes of the formation environment of our Solar System within the Milky Way Galaxy. The first-formed solids in the Solar System, calcium-, aluminum-rich inclusions (CAIs) in meteorites, record the one-time existence of SLRs such as 10Be and 26Al in the solar nebula. We measured the 10Be–10B isotope systematics in 29 CAIs from several CV3, CO3, CR2, and CH/CB chondrites and show that all except for a FUN CAI record a homogeneous initial 10Be/9Be with a single probability density peak at 10Be/9Be = 7.4 × 10–4. Integrating these data with those of previous studies, we find that most CAIs (81%) for which 10Be–10B isotope systematics have been determined, record a homogeneous initial 10Be/9Be ratio in the early Solar System with a weighted mean 10Be/9Be = (7.1 ± 0.2) × 10–4. This uniform distribution provides evidence that 10Be was predominantly formed in the parent molecular cloud and inherited by the solar nebula. Possible explanations for why unusual CAIs (FUNs, PLACs, those from CH/CBs, and those irradiated on the parent body) recorded a 10Be/9Be ratio outside of 7.1 × 10−4 include the following: 1) They incorporated a component of 10Be that was produced in the nebula by irradiation; 2) they formed after normal CAIs; and 3) they were processed (post-formation) in a way that affected their original 10Be signatures. Given the rarity of these examples, the overall uniformity of initial 10Be/9Be suggests that Solar System 10Be was predominantly inherited from the molecular cloud.",
keywords = "Astrophysics, Beryllium-10, CAIs, Carbonaceous chondrites, Cosmochemistry, Molecular cloud, SIMS, Short-lived radionuclides",
author = "Dunham, {E. T.} and M. Wadhwa and Desch, {S. J.} and Liu, {M. C.} and K. Fukuda and N. Kita and Hertwig, {A. T.} and Hervig, {R. L.} and C. Defouilloy and Simon, {S. B.} and J. Davidson and Schrader, {D. L.} and Y. Fujimoto",
note = "Funding Information: We thank associate editor Dr. Thorsten Kleine for editorial handling and Dr. Andrew Davis and two anonymous reviewers for careful reviews that greatly improved the manuscript. We are grateful to Dr. Lynda Williams for her assistance in the ASU SIMS lab. We thank Dr. Ryan Ogliore and Dr. Chris Coath for useful discussions about statistics and ratio determination. We acknowledge the use of facilities within the Eyring Materials Center at ASU, supported in part by NNCI-ECCS-1542160, with the assistance of Dr. Axel Wittmann. We acknowledge ASU{\textquoteright}s Buseck Center for Meteorite Studies collection for providing samples of NWA 5028, NWA 6991 (CAI B4), Leoville, Allende (CAI CMS-1), NWA 7891, and NWA 7892; the Field Museum of Natural History for Allende CAIs TS23A and TS68; Dr. Gregory Brennecka for providing samples of DaG 005 and DaG 027; Dr. Devin Schrader for providing sample Shi{\c s}r 033; Dr. Glenn MacPherson for providing the Vigarano sample with CAI 3137, and the US Antarctic meteorite collection for samples of DOM 08006, MIL 090657, and LAP 02342. The US Antarctic meteorite samples are recovered by the Antarctic Search for Meteorites (ANSMET) program, which has been funded by NSF and NASA, and characterized and curated by the Department of Mineral Sciences of the Smithsonian Institution and the Astromaterials Acquisition and Curation Office at NASA Johnson Space Center. We acknowledge some prominent women astronauts and researchers in astronomy, geology, and physics by naming the CO3 and CH/CB CAIs studied here after them (Goeppert, Jemison, Anning, Mitchell, Bascom, Krafft, Burnell, Meitner, Rubin, Tharp, and Tereshkova); these women{\textquoteright}s achievements and contributions to science remain largely unacknowledged, and they are deserving of greater recognition. This work is supported by the NASA Earth and Space Sciences Fellowship grant NNX1AP48H (ETD and MW), 51 Pegasi b grant #2020-1829 (ETD), and grants NNX15AH41G (MW), NNX17AI43G (SS), and 80NSSC18K0602 (ML) from the NASA Emerging Worlds program. The results reported herein benefitted from collaborations and/or information exchange within NASA{\textquoteright}s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA{\textquoteright}s Science Mission Directorate; we gratefully acknowledge support from NExSS grant NNX15AD53G (SJD). The UCLA ion microprobe facility is partially supported by a grant from the NSF Instrumentation and Facilities program ( EAR-1734856 ; ML), as is the ASU secondary ion mass spectrometer (NSF EAR 1819550 ; RLH). WiscSIMS is partly supported by NSF ( EAR-1658823 ; NK). Funding Information: We thank associate editor Dr. Thorsten Kleine for editorial handling and Dr. Andrew Davis and two anonymous reviewers for careful reviews that greatly improved the manuscript. We are grateful to Dr. Lynda Williams for her assistance in the ASU SIMS lab. We thank Dr. Ryan Ogliore and Dr. Chris Coath for useful discussions about statistics and ratio determination. We acknowledge the use of facilities within the Eyring Materials Center at ASU, supported in part by NNCI-ECCS-1542160, with the assistance of Dr. Axel Wittmann. We acknowledge ASU's Buseck Center for Meteorite Studies collection for providing samples of NWA 5028, NWA 6991 (CAI B4), Leoville, Allende (CAI CMS-1), NWA 7891, and NWA 7892; the Field Museum of Natural History for Allende CAIs TS23A and TS68; Dr. Gregory Brennecka for providing samples of DaG 005 and DaG 027; Dr. Devin Schrader for providing sample Shi?r 033; Dr. Glenn MacPherson for providing the Vigarano sample with CAI 3137, and the US Antarctic meteorite collection for samples of DOM 08006, MIL 090657, and LAP 02342. The US Antarctic meteorite samples are recovered by the Antarctic Search for Meteorites (ANSMET) program, which has been funded by NSF and NASA, and characterized and curated by the Department of Mineral Sciences of the Smithsonian Institution and the Astromaterials Acquisition and Curation Office at NASA Johnson Space Center. We acknowledge some prominent women astronauts and researchers in astronomy, geology, and physics by naming the CO3 and CH/CB CAIs studied here after them (Goeppert, Jemison, Anning, Mitchell, Bascom, Krafft, Burnell, Meitner, Rubin, Tharp, and Tereshkova); these women's achievements and contributions to science remain largely unacknowledged, and they are deserving of greater recognition. This work is supported by the NASA Earth and Space Sciences Fellowship grant NNX1AP48H (ETD and MW), 51 Pegasi b grant #2020-1829 (ETD), and grants NNX15AH41G (MW), NNX17AI43G (SS), and 80NSSC18K0602 (ML) from the NASA Emerging Worlds program. The results reported herein benefitted from collaborations and/or information exchange within NASA's Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA's Science Mission Directorate; we gratefully acknowledge support from NExSS grant NNX15AD53G (SJD). The UCLA ion microprobe facility is partially supported by a grant from the NSF Instrumentation and Facilities program (EAR-1734856; ML), as is the ASU secondary ion mass spectrometer (NSF EAR 1819550; RLH). WiscSIMS is partly supported by NSF (EAR-1658823; NK). Publisher Copyright: {\textcopyright} 2022 The Authors",
year = "2022",
month = may,
day = "1",
doi = "10.1016/j.gca.2022.02.002",
language = "English (US)",
volume = "324",
pages = "194--220",
journal = "Geochimica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier Limited",
}