Discrete lithofacies discrimination of Jurassic strata using Advanced Spaceborne Thermal Emission and Reflection Radiometer Data, Bighorn Basin, Wyoming, USA

An investigation of the carbonate sedimentology of the Middle Jurassic strata, Bighorn Basin, North-central Wyoming, proved to be an ideal test of new spaceborne remote sensing platforms with high spatial and spectral resolution. To evaluate these new tools, it was necessary to: (i) map the occurrence of different lithofacies in at least a part of the area to establish ground truth; (ii) establish the reflectance characteristics of the different lithofacies using portable, on the ground, systems; (iii) produce maps based on spaceborne remote sensing data that discriminate between the lithological types found in the field; and, lastly, (iv) evaluate the discrimination by visiting previously unvisited areas in which these rock types are predicted to occur based upon their remote signatures. Field checking of previously unvisited outcrops demonstrated whether these remote sensing techniques allowed distinction of different lithological outcrops. This investigation determined that the new spaceborne tools could distinguish between outcrops of sparse silty oomicrites from sorted biosparites as small as 10 m by 10 m. In a study area as large as the Bighorn Basin, the ability to identify very small outcrops with a predicted lithology a priori proved to be a major advantage in maximizing field effort.