JMDMT #1316 Microfossils of Cyanobacteria in Carbonaceous Meteorites

The James M. DuPont Meteorite Collection - with the formation of nonporous andradite/hedenbergite rims (for detailed description see [2,4]) around clasts that had been affected by aqueous alteration and probably occurred during this later episode of thermal metamorphism. The presence of feldspathoids in the matrix of Allende [12] and the similarity in bulk composition of this meteorite [13] and those of altered dark inclusions confirm that Allende host materials were affected by significant amounts of alteration [4,14]. The presence in Allende host of dark inclusions that display a variety of textures and bulk compositions emphasizes the importance of regolithic mixing on the Allende parent body. References: [1] Palme H. et al. (1989) Zeitschr. Naturforsch., 44a, 1005-1014. [2] Johnson C. A. et al. (1990) GCA,