DOI: 10.1016/j.epsl.2018.02.029
Scopus记录号: 2-s2.0-85043285914
论文题名: Calcium and titanium isotopes in refractory inclusions from CM, CO, and CR chondrites
作者: Kööp L. ; Davis A.M. ; Krot A.N. ; Nagashima K. ; Simon S.B.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 489 起始页码: 179
结束页码: 190
语种: 英语
英文关键词: calcium isotopes
; calcium–aluminum-rich inclusions (CAIs)
; CO chondrites
; CR chondrites
; fractionation and unidentified nuclear effects (FUN)
; titanium isotopes
Scopus关键词: Aluminum compounds
; Calcium
; Calcium compounds
; Isotopes
; Titanium
; Titanium compounds
; Uncertainty analysis
; Ca , Al-rich inclusions
; Calcium isotopes
; Homogeneous distribution
; Isotopic characteristics
; Measurement uncertainty
; Mutual exclusivities
; Nuclear effects
; Oxygen isotopic composition
; Meteorites
英文摘要: Previous studies have shown that CV and CM chondrites incorporated Ca, Al-rich inclusions (CAIs) with different isotopic characteristics, which may represent different snapshots in the isotopic evolution of the early Solar System. To better understand how the isotopic characteristics of CAIs vary between different chondrite groups, we have studied calcium and titanium isotopes in CAIs from CM, CO, and CR chondrites. We show that all three chondrite groups contain CAIs with large anomalies in 48Ca and/or 50Ti (10s of ‰ or 100s of ε-units) as well as CAIs with no anomalies resolved beyond measurement uncertainties. Isotopically, the anomalous CO and CR chondrite CAIs resemble the platy hibonite crystals (PLACs) from CM chondrites, but they are more mineralogically complex. The new data are consistent with the well-established mutual exclusivity relationship between incorporation of 26Al and the presence of large anomalies in 48Ca and 50Ti. The two highly anomalous CO chondrite CAIs have correlated anomalies in 46Ti and 50Ti, while most other highly anomalous CAIs do not. This result could indicate that the reservoir with coupled 46Ti and 50Ti that was sampled by bulk meteorites and CV chondrite CAIs already existed before arrival and/or homogeneous distribution of 26Al in the protoplanetary disk. Among the studied CM chondrite CAIs are ten spinel-hibonite inclusions (SHIBs) with known oxygen isotopic compositions. Our results show that these objects sampled a reservoir that was well-mixed in oxygen, calcium, and titanium isotopes. We further show that SHIBs tend to be slightly enriched in the heavy calcium isotopes, suggesting that their formation history was different from CV chondrite CAIs. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109961
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of the Geophysical Sciences, The University of Chicago, Chicago, IL 60637, United States; Chicago Center for Cosmochemistry, The University of Chicago, Chicago, IL 60637, United States; Robert A. Pritzker Center for Meteoritics and Polar Studies, Field Museum of Natural History, Chicago, IL, United States; Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637, United States; Hawai‘i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, HI, United States; Institute of Meteoritics, University of New Mexico, Albuquerque, NM 87131, United States
Recommended Citation:
Kööp L.,Davis A.M.,Krot A.N.,et al. Calcium and titanium isotopes in refractory inclusions from CM, CO, and CR chondrites[J]. Earth and Planetary Science Letters,2018-01-01,489