Search for extinct 36Cl: Vigarano CAIs, the Pink Angel from Allende, and a Ningqiang chondrule

If the variability of 36Cl abundances is caused by temporal differences in the alteration that formed sodalite, sodalite in the Vigarano CAIs and in the Ningqiang chondrule may have formed ⩾0.5 and ⩾0.2 Ma after formation of the sodalite in the Ningqiang CAI analyzed by Lin et al. [Lin, Y., Guan, Y., Leshin, L. A., Ouyang, Z. and Wang, D. (2005) Short-lived chlorine-36 in a Ca- and Al-rich inclusion from the Ningqiang carbonaceous chondrite. Proc. Natl. Acad. Sci. USA 102, 1306-1311]. The Pink Angel sodalite that we analyzed may have formed ∼0.3 Ma after formation of the sodalite in the Pink Angel analyzed by Hsu et al. [Hsu, W., Guan, Y., Leshin, L. A., Ushikubo, T. and Wasserburg G. J. (2006) A late episode of irradiation in the early solar system: Evidence from extinct 36Cl and 26Al in meteorites. Astrophys. J. 640, 525-529]. The estimated temporal differences suggest that alteration extended over at least 0.5 Ma. If previous works showing very low initial 36Cl/35Cl in the Allende CAIs and a H3 chondrite CAI are also considered, then alteration processes may have been more than 1.7 Ma.