| Synopsis | The northeast-striking, shallowly northwest-dipping Corvallis fault zone forms the western margin of the southern Willamette Valley in the vicinity of Corvallis. The fault thrusts Eocene Siletz River Volcanics over siltstone and sandstone of the Eocene Tyee Formation The fault may have been reactivated as a steeply dipping left-lateral strike-slip fault. The fault trace is offset by two northwest-striking strike-slip faults that appear to be tear faults in the thrust sheet; however, these faults may extend eastward into the Willamette Valley and thus may not be not tear faults. No unequivocal evidence of Quaternary deformation has been described, so, herein the fault is classified as Class B until further studies are conducted. |
| County(s) and State(s) | BENTON COUNTY, OREGON |
| AMS sheet(s) | Salem |
| Physiographic province(s) | PACIFIC BORDER |
| Length (km) | 40 km. |
| Average strike | N3°E |
| Sense of movement | Thrust |
| Dip Direction | NW |
| Historic earthquake | |
| Most recent prehistoric deformation | Quaternary (<1.6 Ma) |
| Slip-rate category | Less than 0.2 mm/yr |
| Date and Compiler(s) | 2002 Stephen F. Personius, U.S. Geological Survey |
http://gldims.cr.usgs.gov/webapps/cfusion/Sites/qfault/qf_web_disp.cfm?qfault_or=1727&qfault_id=869