The Cordillera Blanca fault zone is a major W dipping normal fault that bounds the W side of a 120- 170-km wide zone of active extension along the crest of the N Peruvian Andes. The fault is approximately 210 km long and exhibits continuous geomorphic evidence of repeated late Pleistocene and Holocene displacements but has not been the source of historical or teleseismically recorded earthquakes. Trenching and mapping of fault scarps provide new information on earthquake recurrence, slip rate, timing of the most recent events and Andean neotectonics. At Quebrada Queroccocha, 55 km from valley fill lacustrine and fluvial deposits are displaced 7.5-8 m. Scarp profiles, tectonic terraces, and trench exposures indicate 5 to 7 scarp-forming earthquakes of 2-3 m per event during the past 11 000-14 000 yrs at this location.-from Author
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Paleoseismicity and neotectonics of the Cordillera Blanca fault zone, Northern Peruvian Andes.