In Lisbon Valley, Utah, Early Cretaceous braided stream deposits of the Lower Burro Canyon Formation form the primary host beds for high-grade copper ore bodies that are potential targets for in-situ leach mining. Variations in the lithology, facies associations, and depositional architecture of the Lower Burro Canyon Formation represent major controls on the porosity, permeability, and connectivity of ore host beds, and are poorly understood in this area.
The goal of this study is to constrain and characterize the lithologic (facies-scale), architectural (element-scale) and stratigraphic (member-scale) heterogeneity that exists within the Lower Burro Canyon Formation in Lisbon Valley in the context of its effect on modern fluid storage and transport.
Detailed logging along a closely spaced (less than 150 meters) transect of five drill-cores revealed the presence of 8 major lithofacies within the Lower Burro Canyon Formation, primarily composed of sandstones, mudstones, and pebble conglomerates. Outcrop-based observations and measurements resulted in the description of 4 distinct architectural element types. Quantitative porosity and permeability data are limited, with existing data showing porosities ranging from approximately 11-22% and permeabilities ranging from approximately 20-325 millidarcies.
