Coarse - Grained Refractory Inclusions : Condensates , Evaporation Residues , or Both ?

A preferred method for the determination of bulk compositions of coarse-grained refractory inclusions and some implications of the results

Analyses of coarse-grained refractory inclusions typically do not have the solar CaO/Al2O3 ratio, probably reflecting nonrepresentative sampling of them in the laboratory. Many previous studies, especially those done by instrumental neutron activation analysis (INAA), were based on very small amounts of material removed from those restricted portions of inclusions that happened to be exposed on...

Forsterite-bearing Type B Cai with a Relict Eringaite-bearing Ultra-refractory Cai

ERINGAITE-BEARING ULTRA-REFRACTORY CAI A. N. Krot, K. Nagashima, C. Ma, G. J. Wasserburg. HIGP, U. Hawai‘, USA. CalTech, USA. Introduction: Forsterite-bearing Type B (FoB) Ca,Al-rich inclusions (CAIs) are a rare type of coarse-grained igneous CAIs found almost exclusively in CV3 chondrites [1–5]. Here we describe the mineralogy, petrography, and oxygen-isotope compositions of a FoB CAI Al-2 fro...

Ti-XANES ANALYSES OF SPINEL IN COARSE-GRAINED REFRACTORY INCLUSIONS FROM ALLENDE

Calcium isotopic ratios and rare earth element abundances in refractory inclusions from the Allende CV3 chondrite

Refractory inclusions in primitive meteorites are the oldest objects formed in the Solar System. They exhibit large massdependent isotopic effects in many elements, including Si, Mg and Ca, indicative of their complex origin. We report data for both mass-dependent (d) and mass-independent (e) Ca isotopic effects, and rare earth element (REE) abundances in six refractory inclusions from the Alle...

Noble Gases in Allende Fluffy and Compact Cais

The Ne and Ar isotopic composition of Allende CAIs can consistently be explained by cosmogenically produced Ne and Ar. Thereby, the extraordinary chemistry of CAIs and the large preatmospheric size of Allende, which may cause significant cosmogenic production of Ar from Cl, were taken into account. In contrast to earlier workers, we conclude that no trapped noble gas components are needed to ex...