The Corvallis fault is a 50 km long northeast-trending structure, part of which defines the boundary between the central Willamette Valley and the east-central Coast Range of Oregon. Previously the fault had been mapped as either a high-angle reverse or normal fault, with the east block down. New gravity data...
Surface geology, seismic data, petroleum exploratory well data, and water well data
have been used to analyze the structural and tectonic history of the southern Willamette
Valley. Tertiary strata beneath the southern Willamette Valley appear to have had an early
Cascade or Clarno volcanic source to the east by the...