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The Al–Mg systems of five ferromagnesian chondrules from the least metamorphosed ordinary chondrite Semarkona (LL3.0) were studied using a secondary ion mass spectrometer. Their glass or plagioclase portions contain excesses of Mg, and in two chondrules the Mg excesses are well correlated with Al/Mg, which demonstrates the in-situ decay of Al. The initial(More)
Secondary ion mass spectrometer (SIMS) oxygen isotope analyses were performed on 24 clasts, representing 9 clast types, in the Dar al Gani (DaG) 319 polymict ureilite with precisions better than 1‰. Olivine-rich clasts with typical ureilitic textures and mineral compositions have oxygen isotopic compositions that are identical to those of the monomict(More)
Introduction: Ureilitic meteorites are ultramafic rocks with highly depleted REE abundance, while showing primitive signatures, such as abundant noble gases and oxygen isotopic heterogeneities. A lack of basaltic components among ureilitic meteorites is the major cause of our poor understanding of their evolution. Especially, chronological studies of(More)
Two fragments with molecular weights of 105,000 (fragment I) and 58,000 (fragment II) were separated chromatographically from each other after Clostridium botulinum type A derivative toxin adsorbed onto a QAE-Sephadex column was treated with dithiothreitol and urea. They were antigenic and formed crossing precipitin lines against anti-derivative toxin in(More)
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