Oxygen isotopic compositions of Allende Type C CAIs: Evidence for isotopic exchange during nebular melting and asteroidal metamorphism

Krot, Alexander N.; Chaussidon, M.; Yurimoto, H.; Sakamoto, Naoya; Nagashima, K.; Hutcheon, I. D.; MacPherson, G. J.

doi:10.1016/j.gca.2008.02.011

Cited by 53 publications

(41 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…15.31; Krot et al unpublished) are consistent with this hypothesis. The common presence of 16 O-rich melilite and/or anorthite in CAIs from Kaba (petrologic type 3.1, Nagashima et al 2007) and Efremovka (petrologic type 3.1-3.4, Fagan et al 2004;Aléon et al 2005;Krot et al 2008;Nagashima et al 2010) and the exceptionally rare presence of 16 Orich melilite or anorthite in CAIs from Allende (petrologic type >3.6) supports this suggestion. Experimental data on oxygen-isotope self-diffusion in melilite and anorthite, under hydrothermal conditions, are required to test this hypothesis.…”

Section: Oxygen Isotopic Compositions Of Cafe-silicates and Magnetitmentioning

confidence: 84%

“…Mineralogy and Petrography Hutcheon and Newton 1981;Hashimoto and Grossman 1987;McGuire and Hashimoto 1989;Lin et al 2005;Fagan et al 2007;Ushikubo et al 2007;Brearley 2008, 2010;Ishii et al 2010;Krot et al 2007Krot et al , 2008Krot et al , 2010 (Ford and Brearley 2010). Melilite and anorthite are the major primary CAI minerals susceptible to alteration; åkermanitic melilite is generally more altered than gehlenitic melilite.…”

Section: Metasomatic Alteration Of the CV Chondrite Componentsmentioning

confidence: 99%

“…15.2.6), support formation of the secondary Ca,Fe-silicates, fayalite, magnetite, and alkali-rich minerals (nepheline, sodalite, wadalite, Na-melilite) in all CV chondrite components by interaction with an isotopically heavy, 16 O-depleted reservoir on the CV parent body. 16 O-rich compositions (e.g., Yurimoto et al 1998;Kim et al 2002;Ito et al 2004;Fagan et al 2004;Aléon et al 2005;Krot et al 2008), oxygen isotopic exchange, between originally 16 O-rich CAIs and a 16 O-depleted external reservoir, is required.…”

Section: Oxygen Isotopic Compositions Of Cafe-silicates and Magnetitmentioning

confidence: 99%

See 2 more Smart Citations

Metasomatism in the Early Solar System: The Record from Chondritic Meteorites

Brearley

Krot

2012

Lecture Notes in Earth System Sciences

103

View full text Add to dashboard Cite

Mineralogic, petrologic, and isotopic studies of chondritic meteorites have revealed a significant body of evidence of metasomatic processes during the earliest stages of Solar System evolution. The exact nature of these processes, as well as the conditions and environments where metasomatism occurred, are still the subject of vigorous debate. The interaction of aqueous fluids with early Solar System solids affected different chondrite groups to different degrees: even within a single chondrite group the effects of metasomatism can be highly variable. Among the carbonaceous chondrite groups, the CV (Vigarano-type) and CO (Ornans-type) chondrites show the best documented evidence of metasomatic effects. In the oxidized subgroup of the CV chondrites, Ca-Al-rich Inclusions (CAIs), Amoeboid Olivine Aggregates (AOAs), chondrules, and matrix have all been extensively affected by Fe-alkali-halogen metasomatism, that has resulted in the formation of a wide range of secondary, dominantly anhydrous minerals, including grossular, andradite, wollastonite, monticellite, anorthite, forsterite, ferroan olivine, corundum, Na-melilite, nepheline, sodalite, wadalite, Al-diopside, kushiroite, ferroan diopside À hedenbergite pyroxenes, ilmenite, phosphates, magnetite, awaruite, tetrataenite, and Fe,Ni sulfides. Hydrous phases are much rarer, but include, margarite, vesuvianite, and kaolinite. The mineral assemblages that form are highly dependent on the primary mineralogy of the host object: distinct mineral assemblages are produced by alteration of CAIs, chondrules, and matrix, for example. Nebular and asteroidal scenarios for these metasomatic effects have been extensively discussed in the literature for the metasomatism observed in the

show abstract

Section: Oxygen Isotopic Compositions Of Cafe-silicates and Magnetitmentioning

confidence: 84%

Section: Metasomatic Alteration Of the CV Chondrite Componentsmentioning

confidence: 99%

Section: Oxygen Isotopic Compositions Of Cafe-silicates and Magnetitmentioning

confidence: 99%

See 1 more Smart Citation

Metasomatism in the Early Solar System: The Record from Chondritic Meteorites

Brearley

Krot

2012

Lecture Notes in Earth System Sciences

103

View full text Add to dashboard Cite

show abstract

“…Detailed studies continue to focus on a variety of components within these meteorites, including: refractory inclusions (Thrane et al, 2006;Krot et al, 2008), presolar grains (Verchovsky et al, 2006;Marhas et al, 2007), organic material (Pizzarello et al, 2006), silicate chondrules ( Libourel and Krot, 2007;. These materials were formed in diverse environments, ranging from pre-nebular to asteroidal (McSween et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

The relationship between CK and CV chondrites

Greenwood¹,

Franchi²,

Kearsley³

et al. 2010

Geochimica et Cosmochimica Acta

100

195

View full text Add to dashboard Cite

CK chondrites are highly oxidized meteorites containing abundant magnetite and trace amounts of Fe,Ni-metal. Although the group is predominately composed of equilibrated meteorites (types 4 to 6), in recent years a significant number of new samples have been classified as being either CK3 or CK3-anomalous. These unequilibrated CKs often display a close affinity with members of the CV oxidized subgroup. CKs and CVs (oxidized subgroup) may therefore form a continuum and by implication could be derived from a single common parent body. To investigate the relationship between these two groups a detailed study of the oxygen isotope composition, opaque mineralogy and major and trace element geochemistry of a suite of CV and CK chondrites has been undertaken. The results of oxygen isotope analysis confirm the close affinity between CV and CK chondrites, while excluding the possibility of a linkage between the CO and CK groups. Magnetites in both CV and CK chondrites show significant compositional similarities, but high Ti contents are a diagnostic feature of the latter group. The results of major and trace element analysis demonstrate that both CV and CK chondrites show overlapping variation. Supporting evidence for a single common source for both groups comes from their similar cosmic-ray exposure age distributions. Recent reflectance spectral analysis is consistent with both the CVs and CKs being derived from Eos family asteroids, which are believed to have formed by the catastrophic disruption of a single large asteroid. Thus, a range of evidence appears to be consistent with CV and CK chondrites representing samples from a single thermally stratified parent body. In view of the close similarity between CV and CK chondrites some modification of the present classification scheme may be warranted, possibly involving integration of the two groups. One means of achieving this would be to reassigned CK chondrites to a subgroup of the oxidized CVs. It is recognized that a full evaluation of this proposal may require further study of the still poorly understood CK3 chondrites. ACCEPTED MANUSCRIPT3

show abstract

“…The preliminary studies of trace element abundances and oxygen isotopic compositions have been described by Huss et al (2002) and Krot et al (2007b). Here, we report the mineralogy and petrography of five Type C CAIs from Allende: 100, 160, CG5, 6-1-72, and 3529-40, and two Al-rich chondrules (3510-7 and 3555B-2), and compare them with our recent results on three chondrule-bearing Type C CAIs from Allende ABC, 93, and TS26 (Krot et al, 2005b(Krot et al, , 2007b. Although most of the Allende Type C CAIs described here have been previously studied by Wark (1987), we think that some important aspects of their formation have been overlooked.…”

Section: Introductionmentioning

confidence: 99%