This grant provides continued support for the University of Texas Computed X-ray Tomography (UTCT) Facility over a three year period. The CT scanner at UT was specifically designed to enable x-ray tomography of a range of geological materials and sample sizes. The technology was developed from commercial biomedical CAT scanners with the adoption of a higher energy x-ray source and higher resolution CCD detectors to allow micron-scale imaging of non-living geological samples. The technique allows for completely non-destructive imaging of the exteriors and interiors of samples. Differences in x-ray attenuation that occur due to variations in sample density and the elemental composition of the material along the x-ray path are digitally recorded by a CCD. Samples are mounted on a rotating table in front of the x-ray source. Radial 2-d slices of the attenuated x-rays are stacked by vertical translation of the sample table. Resultant x-ray "sinograms" are then reduced via computer algorithms to render high resolution 3-D images of the density distributions within samples. Research applications spanning the geosciences, biology, engineering and anthropology are routinely supported. Data and images from UTCT scans are web-accessible data and extremely useful for teaching.