Buesaco-Aranda Fault

Buesaco-Aranda Fault
Buesaco-Aranda Fault
Falla Buesaco-Aranda
Age	Quaternary
Orogeny	Andean

The Buesaco-Aranda Fault (

strike in the Central Ranges of the Colombian Andes

. The 1995 Pasto earthquake is associated with the active fault showing high amounts of displacement. The earthquake caused seven fatalities.

Etymology

The fault is named after Buesaco and Aranda, a vereda of Pasto.^[1] Other sources call the fault by the general name of Silvia-Pijao Fault.^[2]

Description

The Buesaco-Aranda Fault, extends in a north-northeast to northeast direction from near the

glacial deposits.^[1]

The Buesaco-Aranda Fault has a very well-defined fault trace, with strongly deformed landforms of Pleistocene-Holocene age, clear breaks in slope along eroded

alluvial deposits and in recent alluvial fans have fresh scarp morphology. The net cumulative horizontal slip calculated is 188 ± 14 metres (617 ± 46 ft), with 160 ± 10 metres (525 ± 33 ft) of displacement in offset landforms along the Aranda Fault.^[1] The Morasurco volcano is enclosed by the Buesaco and Aranda Fault segments.^[3]

Activity

The last strong seismic event occurred on the Buesaco Fault near Pasto at 18:23 on March 4, 1995; the magnitude of the biggest shock was M 5.0.[4] Seven people died as a result of the earthquake and the aftershocks.^[5]

References

^ ^a ^b ^c Paris et al., 2000a, p.26
^ Plancha 5-18, 2015
^ Tibaldi & Romero, 2000, p.360
^ (in Spanish) El sismo del 4 de marzo 1995, Pasto
^ (in Spanish) Siete muertos dejaron cuatro sismos en Pasto - El Tiempo

Bibliography

Paris, Gabriel; Michael N. Machette; Richard L. Dart, and Kathleen M. Haller. 2000a. Map and Database of Quaternary Faults and Folds in Colombia and its Offshore Regions, 1–66. USGS. Accessed 2017-09-18.
Tibaldi, Alessandro, and Jaime Romero León. 2000. Morphometry of late Pleistocene-Holocene faulting and volcanotectonic relationship in the southern Andes of Colombia. Tectonics 19. 358–377. Accessed 2017-09-24.

Maps

Paris, Gabriel; Michael N. Machette; Richard L. Dart, and Kathleen M. Haller. 2000b. Map of Quaternary Faults and Folds of Colombia and Its Offshore Regions, 1. USGS. Accessed 2017-09-18.
Gómez Tapias, Jorge; Nohora Emma Montes Ramírez; Álvaro Nivia Guevara, and Hans Diederix. 2015. Plancha 5-18 del Atlas Geológico de Colombia 1:500,000, 1.
Servicio Geológico Colombiano
. Accessed 2017-09-21.

[Paris2000_p26-1] Paris et al., 2000a, p.26

[Plancha_5_18-2] Plancha 5-18, 2015

[Tibaldi2000_p360-3] Tibaldi & Romero, 2000, p.360

[SGC-4] (in Spanish) El sismo del 4 de marzo 1995, Pasto

[TiempoPasto-5] (in Spanish) Siete muertos dejaron cuatro sismos en Pasto - El Tiempo

[1]

[2]

[3]

[5]