B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al

Details B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al

Apr 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003eaeja.....9292c&link_type=abstract

EGS - AGU - EUG Joint Assembly, Abstracts from the meeting held in Nice, France, 6 - 11 April 2003, abstract #9292

Computer Science

1

Scientific paper

The finding [1-3] in Ca-Al-rich refractory inclusions (CAI) of primitive chondrites of traces of the in situ decay of radioactive 10Be (half-life 1.5Myr) indicates that irradiation of the protosolar nebula by the young Sun in its T-Tauri phase has produced significant amounts of the Li-Be-B elements. This irradiation may have produced also some or all of the short-lived 26Al (half-life 0.7Myr) and 41Ca (half-life 0.1Myr) previously detected in CAIs. To constrain the origin of 10Be and 10Al it is important to look for coupled variations in the 10Be/9Be and 26Al/27Al ratios in CAIs and to understand the processes responsible for these variations (e.g. variations in the fluences of irradiation, secondary perturbations of the CAIs, ...) We have thus studied the Li and B isotopic compositions and the Be/Li and Be/B concentration ratios in one CAI (MRS-06) from the Leoville CV3 chondrite in which large variations of the Mg isotopic compositions showing both the in situ decay of 26Al and the secondary redistribution of Mg isotopes have been observed [4]. The results show large variations for the Li and B isotopic compositions (^7Li/^6Li ranging from 11.02±0.21 to 11.82±0.07, and 10B/11B ratios ranging from 0.2457±0.0053 to 0.2980±0.0085). The ^7Li/^6Li ratio tend to decrease towards the rim of the inclusion. The 10B/11B ratios are positively correlated with the ^9Be/11B ratios indicating the in situ decay of 10Be. However perturbations of the 10Be/B system are observed. They would correspond to an event which occurred approximately 2Myr after the formation of the CAI and the irradiation of the CAI precursors which is responsible for the 10Be observed in the core of the CAI. These perturbations seem compatible with those observed for the 26Al/Mg system but they might be due to an irradiation of the already-formed, isolated CAI which would have resulted in increased 10Be/^9Be ratios and low ^7Li/^6Li ratios in the margin of the CAI. [1] McKeegan K. D. et al. (2000) Science, 90, 1334-1337. [2] Sugiura N. et al. et al. (2001) Meteoritics &Planet. Sci., 36, 1397-1408. [3] McPherson G. J. and Huss G. R. (2001) LPS XXXII, Abstract #1882. [4] Ash R. D. et al. (2002) LPS XXXIII, Abstract #2063.

Affiliated with

Also associated with

No associations

Rating

B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and B and Mg isotopic variations in Leoville mrs-06 type B1 cai:origin of 10Be and 26Al will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-844738