Urrao Fault
Etymology
The fault is named after Urrao.
Description
This set of two parallel faults extend along the axis of the Western Ranges of the Colombian Andes, close to the valleys of the Anacosca and Penderisco Rivers, and the plateau of the Frontino Páramo. Located to the west of the city of Medellín, the faults mainly displace Tertiary sedimentary rocks. The west branch of the fault has mainly normal slip as observed from offset alluvial terraces. The fault forms spectacular fault scarps on terraces. These scarps are 10 kilometres (6.2 mi) long and as much as 50 metres (160 ft) high. Most of the fault trace has a moderate alignment of topographic features, such as linear streams and offset spurs. Quaternary alluvial sediments of the Penderisco River are offset an unknown amount. The slip rate is estimated at 0.2 to 1 millimetre (0.0079 to 0.0394 in) per year deduced from displaced Quaternary sediments.
See also
References
- ^ Paris et al., 2000, p.18
- ^ Paris et al., 2000, p.19
Bibliography
- Paris, Gabriel; Machette, Michael N.; Dart, Richard L.; Haller, Kathleen M. (2000a), Map and Database of Quaternary Faults and Folds in Colombia and its Offshore Regions (PDF), USGS, pp. 1–66, retrieved 2017-09-18
Maps
- Paris, Gabriel; Machette, Michael N.; Dart, Richard L.; Haller, Kathleen M. (2000b), Map of Quaternary Faults and Folds of Colombia and Its Offshore Regions (PDF), USGS, p. 1, retrieved 2017-09-18
Further reading
- Page, W.D (1986), Seismic geology and seismicity of Northwestern Colombia, San Francisco, California, Woodward-Clyde Consultants Report for ISA and Integral Ltda., Medellín, pp. 1–200