Three-dimensional structures of extremely C-rich micrometeorites: their distributions of carbonaceous materials and Fe concentrations.

Abstract

3-D structures of three ultra C-rich micrometeorite (UCMM) samples were obtained using SR microtomography at BL47XU of SPring-8 (voxel size: 0.195 micron). C-rich material is pre-sent around a magnetite-rich core in a hydrated UCMM, while they may be present in porous portions in two anhydrous UCMMs. Subtraction method using Fe K-adsorption edge shows that large crystals in the anhydrous UCMMs are poor in Fe than the porous portions.