A Caltech Library Service

Al-Mg systematics of CAIs, POI, and ferromagnesian chondrules from Ningqiang

Hsu, Weibiao and Huss, Gary R. and Wasserburg, G. J. (2003) Al-Mg systematics of CAIs, POI, and ferromagnesian chondrules from Ningqiang. Meteoritics and Planetary Science, 38 (1). pp. 35-48. ISSN 1086-9379. doi:10.1111/j.1945-5100.2003.tb01044.x.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We have made aluminum-magnesium isotopic measurements on 4 melilite-bearing calcium-aluminum-rich inclusions (CAIs), 1 plagioclase-olivine inclusion (POI), and 2 ferromagnesian chondrules from the Ningqiang carbonaceous chondrite. All of the CAIs measured contain clear evidence for radiogenic ^(26)Mg^* from the decay of ^(26)Al (τ = 1.05 Ma). Although the low Al/Mg ratios of the melilites introduce large uncertainties, the inferred initial ^(26)Al/^(27)Al ratios for the CAIs are generally consistent with the value of 5 x 10^(−5). There is clear evidence of ^(26)Al^* in one POI and two chondrules, but with considerable uncertainties in the value of (^(26)Al/^(27)Al)0. The (^(26)Al/^(27)Al)_0 ratios for the POI and the chondrules are 0.3–0.6 x 10^(−5), roughly an order of magnitude lower than the canonical value. Ningqiang shows very little evidence of metamorphism as a bulk object and the (^(26)Al/^(27)Al)_0 ratios in its refractory inclusions and chondrules are consistent with those found in other unmetamorphosed chondrites of several different classes. Our observations and those of other workers support the view that ^(26)Al was widely and approximately homogeneously distributed throughout the condensed matter of the solar system. The difference in (^(26)Al/^(27)Al)0 between CAIs and less refractory materials seems reasonably interpreted in terms of a ∼2 million year delay between the formation of CAIs and the onset of formation of less refractory objects. The POI shows clear differences in ^(25)Mg/^(24)Mg between its constituent spinels and olivine, which confirms that they are partially reprocessed material from different sources that were rapidly quenched.

Item Type:Article
Related URLs:
URLURL TypeDescription
Huss, Gary R.0000-0003-4281-7839
Wasserburg, G. J.0000-0002-7957-8029
Additional Information:© 2003 The Meteoritical Society. Received 20 February 2002; revision accepted 1 November 2002. Article first published online: 26 Jan 2010. The thin section containing the POI was kindly provided by Dr. Alan Rubin. We appreciate the critical and constructive comments of the reviewers, J. Goswami and N. T. Kita. Their suggestions as well as the thorough and helpful comments by the associate editor, H. Nagahara, have been incorporated to provide a better presentation. This study was supported by NASA NAG5-10293 (GJW) and NAG5-8158 (GRH) and Caltech Division Contribution #8738(1069).
Funding AgencyGrant Number
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences8738
Lunatic Asylum Lab1069
Issue or Number:1
Record Number:CaltechAUTHORS:20140715-134743251
Persistent URL:
Official Citation:Hsu, W., Huss, G. R. and Wasserburg, G. J. (2003), Al-Mg systematics of CAIs, POI, and ferromagnesian chondrules from Ningqiang. Meteoritics & Planetary Science, 38: 35–48. doi: 10.1111/j.1945-5100.2003.tb01044.x
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:47229
Deposited By: Ruth Sustaita
Deposited On:15 Jul 2014 21:27
Last Modified:10 Nov 2021 17:36

Repository Staff Only: item control page