Analysis of deformation bands associated with the Trachyte Mesa intrusion, Henry Mountains, Utah: implications for reservoir connectivity and fluid flow around sill intrusions

Abstract. Shallow-level igneous intrusions are a common feature of many sedimentary basins, and there is increased recognition the syn-emplacement deformation structures in host rock that help to accommodate this magma addition. However, sub-seismic structure reservoir-scale implications remain poorly understood. The Trachyte Mesa intrusion small (?1.5 km2), NE–SW trending satellite Oligocene-age Mount Hillers intrusive complex Henry Mountains, Utah. It emplaced within highly porous, aeolian Entrada Sandstone Formation (Jurassic), producing network conjugate sets striking bands parallel margins. was characterized by defining series nodes branches, from which topology, frequency, intensity, spacing, characteristic length, dimensionless intensity band traces branches were determined. These quantitative geometric topological measures supplemented petrological, porosity microstructural analyses. Results show marked increase significant reduction with increasing proximity intrusion. likely impede fluid flow, forming barriers baffles reservoir unit. A corresponding Y- X-nodes highlights connectivity, turn will significantly reduce permeability sandstone. This study indicates flow deformed rocks around bodies may vary undeformed rock. better understanding variability structures, their association geometry, have important for industries where naturally fractured reservoirs adds value (e.g. hydrocarbon deliverability, hydrology, geothermal energy carbon sequestration).