World Library  
Flag as Inappropriate
Email this Article

Calcium–aluminium-rich inclusion

Article Id: WHEBN0000236564
Reproduction Date:

Title: Calcium–aluminium-rich inclusion  
Author: World Heritage Encyclopedia
Language: English
Subject: Chondrule, Lead-lead dating, Meteorite minerals, CAIS, Aluminium-26
Collection: Meteorite Minerals, Solar System Dynamic Theories
Publisher: World Heritage Encyclopedia

Calcium–aluminium-rich inclusion

Chondrite meteorite with calcium–aluminium-rich inclusions seen as white specks

A calcium–aluminium-rich inclusion or Ca–Al-rich inclusion (CAI) is a submillimeter- to centimeter-sized light-colored calcium- and aluminium-rich inclusion found in carbonaceous chondrite meteorites. They are probably the oldest substances in the Solar System. The oldest age was measured in an inclusion of the CV3 carbonaceous chondrite Northwest Africa (NWA) 2364 and was dated at 4568.22 ± 0.17 Mya.[1]


  • Description 1
  • See also 2
  • Bibliography 3
  • References 4


CAIs consist of minerals that are among the first solids condensed from the cooling protoplanetary disk. They are thought to have formed as fine-grained condensates from a high temperature (>1300 K) gas that existed in the protoplanetary disk at early stages of Solar System formations. Some of them were probably remelted later resulting in distinct coarser textures. The most common and characteristic minerals in CAIs include anorthite, melilite, perovskite, aluminous spinel, hibonite, calcic pyroxene, and forsterite-rich olivine.

Using lead (Pb–Pb) isotopic data determined in mineral separates of a CAI from NWA 2364, an age of 4568.22 ± 0.17 million years has been calculated, which can be interpreted as the beginning of the formation of the planetary system.[1] Radiometric dating with Pb–Pb, Al–Mg and Cr–Mn chronometers shows that the CAIs formed up to 3 million years before the chondrules appeared, although some chondrules may have formed simultaneously with some CAIs.

See also


  • Bouvier A., and Wadhwa, M., 2010. "The Age of the Solar System redefined by the oldest Pb-Pb age of a meteoritic inclusion." Nature Geoscience, v. 3, pp. 637-641. DOI: 10.1038/NGEO941
  • MacPherson, G. J. (2004) Calcium-aluminum-rich inclusions in chondritic meteorites. In Treatise on Geochemistry, Volume I, Meteorites, Comets, and Planets, A. M. Davis, edt., Elsevier, New York, pp. 201–246. ISBN 0-08-043751-6
  • Krot, A. N. (September 2002) Dating the Earliest Solids in our Solar System. Planetary Science Research Discoveries.
  • Shukolyukov A., Lugmair G.W. (2002) Chronology of Asteroid Accretion and Differentiation, pp. 687–695, in Asterois III, Bottke W.F., Cellino A., Paolicchi P., Binzel R.P., eds., University of Arizona Press (2002), ISBN 0-8165-2281-2


  1. ^ a b Bouvier, Audrey; Wadhwa, Meenakshi (2010). "The age of the Solar System redefined by the oldest Pb–Pb age of a meteoritic inclusion". Nature Geoscience 3 (9): 637–641.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.