FLUID MIGRATION IN FAULTS: ANALYSIS OF THE HITE FAULT GROUP

We evaluate low permeability fault damage zones within Permian Cedar Mesa Sandstone, southeastern Utah, in order to examine fluid migration pathways and barriers in an exhumed flow system. We examine the Hite fault group in the Glen Canyon National Recreation Area, where reservoir levels have dropped and exposed a set of northwest-striking normal faults sub meter to ~7m of throw. Individual fault damage zones have associated deformation bands and zones of calcite and hematite mineralized fractures. Within the damage zones ultraviolet-light-induced fluorescence has examined the various types mineralized fractures (Petrie et al., 2014) and indicates that there is fluid pathway connectivity and a possible shared history of mineralization in the damage zones. In field area 34 faults and associated damage zones were mapped at 1:10,000 scale, of these three faults were selected to be transected and sampled for further analysis. Fault surfaces strikes on an average of ~305ᵒ, fracture parallel fault surface with some variance. Fracture densities in these the damage zone range from ~3 fractures per meter to ~18 fractures per meter. All fractures within the selected damage zones are mineralized to some degree. In preliminary thin section analysis micro scale structures have been observed and zones of mineralization have been more closely examined. Whole rock geochemical analysis and x-ray diffraction analyses are currently being performed and from these we will determine variations in rock chemistry as samples were from the protolith towards the center of the damaged zone giving further evidence for fluid flow through low permeability fault zones.