JMDMT #1744 Microfossils of Cyanobacteria in Carbonaceous Meteorites

The James M. DuPont Meteorite Collection - consistent with immersion in a slightly acidic fluid, exhibiting preferential removal of Fe-rich glass interstitial to Mg-rich olivine bars. In addition, the full range of expected morphologies for cosmic spherules is present, from glassy, fully melted and devolatilized spherules to bubble-rich, cryptocrystalline and relict-grain bearing particles retaining "meteoritic" mineral compositions. Unmelted micrometeorites with a texture similar to those found in other Antarctic collections[4] are also found in the SPWW sediment. These somewhat porous particles have a compacted, dark matrix containing metal, sulfide, and silicate grains with chondritic composition; and a fine, glassy Fe-rich rim surrounds the particle and most vesicles. Detailed examinations of non-spherical