Fluid flow and chemical alteration in carbonaceous chondrite parent bodies

Carbonaceous chondrites are a class of primitive meteorites that likely represent early solar system materials, thus providing critical insights about planetary evolution. However, evidence shows that they have undergone considerable processing. Elucidating the complex formation history of aqueously altered chondrite groups has been a principal objective of cosmochemistry. Fulfilling this objective requires understanding the nature of the water–rock interactions involved. Many current alteration models are generally founded upon an assumption of uniform alteration in a closed system. In these models, different chondrite groups must originate on separate parent bodies. Contrary to this common view, we show that chondrite data are consistent with non-uniform alteration in a convecting system so that multiple chondrite groups can form within a single body.