GROUND-BASED LUMINESCENCE MEASUREMENT AT BROWN-BASSETT FIELD, TEXAS

Luminescence and reflectance measurements made on Cretaceous carbonate rocks and thin soils showed significant variation over and adjacent t o the Brown-Bassett gas field. Luminescence and reflectance were measu red for ten rock and ten soil samples at each of 40 sites using a Frau nhofer Line Radiometer Analysis of variance models with lithologic des criptors for color, lithology, and texture as covariates were used to calculate average values of luminescence for each site. The lithologic descriptors were assigned ordinal values based on a hierarchical sche me, then tested for significance using t-tests prior to inclusion in t he model. Significant differences were observed between site means. Si tes with high luminescence generally corresponded to areas overlying o r near the Brown-Bassett field. Sites with low values of luminescence were generally off-field. The total range of mean values for relative luminescence of rocks and soils at the 40 measured sites was three tim es the average variation of luminescence of samples at a site.