Abstract
Titanium and calcium are both refractory lithophile elements. Significant stable isotopic variations on Ti and Ca have been documented within calcium, aluminum-rich inclusions (CAIs) in carbonaceous chondrites. To trace the condensation history of Ti in the solar nebula, we conducted a high-precision double-spike Ti stable isotopic study on a large set of chondrites. The studied chondrites have a homogeneous bulk Ti stable isotopic composition (δ49/47TiIPGP-Ti = −0.069 ± 0.018‰ 2se, n = 22, i.e., the per mil deviation of the 49Ti/47Ti ratios relative to the IPGP-Ti reference material). The homogeneity across eleven chondrite groups implies that chondrites have acquired, through the condensation sequence at equilibrium, the average stable isotopic composition of Ti in the refractory solids that condensed early in the solar nebula. In contrast, the light Ca stable isotopic compositions of bulk chondrites can be attributed to either the presence of CAIs (CV-, CM- and CO-type) or parent-body aqueous alteration (CR- and CI-type).
Original language | English |
---|---|
Pages (from-to) | 409-419 |
Number of pages | 11 |
Journal | Geochimica et Cosmochimica Acta |
Volume | 239 |
Early online date | 23 Jun 2018 |
DOIs | |
Publication status | Published - 15 Oct 2018 |
Funding
We thank Julien Moureau, Pascale Louvat, Jessica Dallas and Pierre Burckel for maintaining the MC-ICP-MS and Q-ICP-MS at IPGP, John Creech for his help with IsoSpike software, and Marc-Alban Millet for sharing the OL-Ti standard. Dimitri Papanastassiou, Justin Simon and two anonymous reviewers are greatly appreciated for their constructive comments on our manuscript. FM acknowledges funding from the Parts of this work were supported by IPGP multidisciplinary program PARI, and by Region Île-de-France SESAME Grant no. 12015908. We are also indebted to Joseph Boesenberg and Denton Ebel (American Museum of National History, New York), Timothy McCoy (US National Museum of Natural History, Smithsonian Institution, Washington DC), Caroline Smith (The Natural History Museum, London), Alex Bevan (Western Australian Museum, Perth), Jim Karner and Carl Agee (University of New Mexico, Albuquerque), Ludovic Ferriere (Naturhistorisches Museum, Vienna), Philip Heck (The Field Museum, Chicago), Meenakshi Wadhwa (Arizona State University, Tempe), Cecilia Satterwhite (NASA Johnson Space Center, Houston) and the Comité de Gestion (Museum Nationale d’Histoire Naturelle, Paris) for their generous donations of meteorite samples for this work and their confidence in our analytical and scientific capabilities. European Research Council under the H2020 framework program/ERC grant agreement # 637503 (Pristine). FM and MC thank financial support from the ANR through the Cradle project and the UnivEarthS Labex program at Sorbonne Paris Cité (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02).
Funders | Funder number |
---|---|
H2020 framework program/ERC | |
Region Île-de-France | 12015908 |
European Research Council | 637503 |
Labex UnivEarthS | ANR-10-LABX-0023, ANR-11-IDEX-0005-02 |
Keywords
- Calcium isotopes
- Chondrites
- Double spike
- Titanium isotopes