Poster Number 311
See more from this Division: Topical Sessions
See more from this Session: Sigma Gamma Epsilon Undergraduate Research (Posters)
Abstract:
We identified a primary fracture set with a mean orientation of tr. 352° pl. 15.9°. This orientation corresponds with the principal stress direction of the Laramide Orogeny. These fractures were at least 100 m in length with a mean fracture spacing of 28.0 m, which appears to be independent of location within the monocline exposed in White Creek Canyon. A zone of paleokarst features was identified at the base of the Mission Canyon Member. This paleokarst was infilled by collapse breccia, calcite, and speleofluvial deposits. Open karst features were discontinuous, dry, and displayed an apparently random orientation. Our observations suggest that groundwater flows primarily through fracture networks and not paleokarst in this aquifer. This conclusion is supported by similar studies conducted in Trapper Creek Canyon south of this study area. The large fracture spacing and lack of relationship between spacing and structure may explain the highly variable yield of wells completed in the Madison locally. We are hopeful that continuing investigation of White Creek Canyon will reveal a contemporary karst system interconnected with fractures that could be used as an aquifer for nearby residents.
See more from this Division: Topical Sessions
See more from this Session: Sigma Gamma Epsilon Undergraduate Research (Posters)