Recent Activity of the Wasatch Fault, Northwestern Utah, U.S.A.

摘要: Abstract The Wasatch fault trends north—south for a total length of 370 km, between Gunnison, Utah and Malad City, Idaho. is in the eastern Basin-and-Range Province, adjacent to Middle Rocky Mountains Colorado Plateau. most recent displacements indicate normal slip, with western block faulted down relative Mountains. within Intermountain Seismic Belt U.S.A.; however, it has been associated only minor seismicity historic time (140 yrs). There no conclusive evidence significant surface faulting along Wasatch, although there concentrated 50–100-m-wide zone damaged streets, curbs, houses, buildings where through Salt Lake City. This damage may be interpreted as tectonic creep; other possible interpretations include fault-controlled related slope instability steep scarp or groundwater. Precise geodetic leveling across City segments suggests that creep occurring, span (7 yrs) not long enough establish consistent trend. Geomorphic tree-ring dating suggest events appreciable are older than few hundred years. Fresh scarps geologically young glacial post-glacial deposits 13–20 m high. Surface manifestations active multiple-fault scarplets materials, graben on downthrown block, backward tilting near fault, triangular facets scarp, lines springs, slickensided surfaces. In addition geologic faulting, numerous landslides large debris flows have subsequent their deposition, linear geomorphic features indicative cross them. Our current research activity directed toward determining history relationship large-magnitude earthquakes, which based upon sequence Pleistocene Bonneville beds Front.