Holocene surface faulting along the west flank of the Santa Rosa Range (Nevada-Oregon) and the possible northern extension of the Central Nevada Seismic Belt

Conference · Thu Apr 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5127606

Michetti, A M ^[1]; Wesnousky, S G ^[2]

---

1. CNR/GNDT, Rome (Italy) Univ. of Nevada, Reno, NV (United States). Center for Neotectonic Studies
2. Univ. of Nevada, Reno, NV (United States). Center for Neotectonic Studies

The 130 km long Santa Rose Range fault system extends northward from a point about 70 km north of the 1915 Pleasant Valley earthquake fault ruptures to Blue Mountain Pass, Oregon. The authors have examined 1:12,000 low-sun-angle aerial photographs and conducted surveys of scarp morphology to investigate the neotectonic evolution and paleoseismicity of this possible northern extension of the Central Nevada Seismic Belt. Two adjoining segments of the fault zone are separated by a right step in the range-front and apparent absence of Holocene scarps. Each segment records evidence of a Holocene faulting event. The southern 31 km segment between Frey Ranch and the Willow Creek fan shows both small scarps (< 1 m) which cut Lahontan shorelines in the fluvio-lacustrine sediments of the Quinn River Valley and larger scarps which oversteepen the base of the adjacent range-front to slopes of 20[degree] to 24[degree]. The northern 42 km segment between Flat Creek and Oregon Canyon Creek shows a recent offset which rejuvenates older (pre-Lahontan) fault scarps and also cuts Holocene terraces along the base of the piedmont pediment. Based on preliminary morphometric data, the maximum vertical displacement (3--4 m) and age of the faulting (early Holocene) are similar in both segments but it is not known whether both segments ruptured contemporaneously. Except for the lack of large historical surface faulting the main neotectonic and geomorphic features of the Santa Rose Range fault zone are similar to that of the Dixie Valley and Pleasant Valley regions of the Central Nevada Seismic Belt. Hence, the occurrence of a large earthquake rupture along this range-front in the near future should not be viewed as a surprise.

• OSTI ID: 5127606
• Report Number(s): CONF-9305259--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
CENOZOIC ERA
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
GEOMORPHOLOGY
NEVADA
NORTH AMERICA
OREGON
QUATERNARY PERIOD
SEISMICITY
STRATA MOVEMENT
USA