Geology of the Vista 7.5' quadrangle, St. Clair County, Missouri

Date of Graduation

Fall 2008


Master of Science in Geospatial Sciences


Geography, Geology, and Planning

Committee Chair

Kevin Evans


The Vista 7.5' quadrangle is located in St. Clair County, 100 kilometers north of Springfield, Missouri. The Weaubleau structure, an anomalous area of intense structural deformation, is located in the northern half of this quadrangle and is interpreted to be a meteorite impact. At the surface, folded, fractured, and locally brecciated strata derived from Mississippian and Ordovician dolomites and limestones characterize the geology. This breccia is informally referred to as the "Weaubleau Breccia" and it crops out irregularly in the northern part of the quadrangle. The Pennsylvanian shale and sandstone succession that overlie these strata is undeformed. Topographically, the Weaubleau structure is delineated by circular drainages that outline an area interpreted as the central uplift. It coincides with outcrops of a fine-grained facies of the "Weaubleau Breccia," which is interpreted as a water-lain resurge breccia. Detailed geologic mapping was conducted in the field combining the use of traditional mapping techniques with geographic information system (GIS)-based methods. A global positioning system (GPS) unit was used in conjunction with a mobile GIS software mapping application (ArcPad), installed on a handheld personal computer. This project produced a detailed geologic map and an assemblage of GIS products for the Vista 7.5' quadrangle that highlight the structural deformation and distribution of rock types associated with the Weaubleau structure. This mapping effort has provided new details concerning the development and evolution of the structure.


GIS, impact, mapping, meteorite, Vista, Weaubleau Breccia

Subject Categories

Geographic Information Sciences | Geology


© Melissa Rochelle Cox