Thermal processing refractory inclusions

Davis AM, MaePherson GJ (1996) Thermal processing in the solar nebula Constraints from refractory inclusions. In Chondrules and the Protoplanetary Disk. Hewins RH, Jones RH, Scott ERD (eds) Cambridge University Press, New York, p 71-76... 

Shortly after the condensation of the first minerals to form within the Solar System, thermal processing of refractory inclusions began. The overall processing of these materials into igneous rocks was short-lived, perhaps only 100000 years (Bizzarro et al. 2007). The critical constraints on the thermal histories of these objects is essentially limited to Type-B CAIs (Connolly Desch 2004), which have been generated by the experimental reproduction of these objects in the laboratory. Type-B CAIs are composed mostly of melilite, anorthite, aluminous spinel, and a titanium-rich pyroxene known in the parlance as fassaite (for a summary of minerals common to the Solar System see Appendix 1). The general consensus is... 

Perhaps the most well-known, unsolved problem in cosmochemistry is the question of the mechanism whereby dust grain aggregates were thermally processed to form chondrules and some rounded refractory inclusions. Chondrule compositions and textures require rapid heating and somewhat slower cooling for their explanation a globally hot nebula is inconsistent with these requirements... 

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