Fine-grained rims surrounding chondrules in the Tagish Lake carbonaceous chondrite: Verification of their formation through parent-body processes

The results suggest that the chondrules, other coarse-grained components, and their rims (generically referred to as chondrules/rims) and the clasts originated from a common precursor region in the meteorite parent-body that was different from the location where the host meteorite was finally lithified. That is, the chondrules/rims are actually clasts produced by brecciation and later transported and incorporated into the present host matrix. The rims are, therefore, remnants of matrix material that formerly filled interspaces between the chondrules and other coarse-grained components. This model is essentially consistent with those previously proposed for the carbonate-rich lithology of Tagish Lake and the hydrated chondrules/rims in the Vigarano and Mokoia CV3 chondrites.