Usme Fault

The Usme Fault (Spanish: Falla de Usme) is a dextral oblique normal fault in the department of Cundinamarca in central Colombia. The fault has a total length of 64.9 kilometres (40.3 mi) and runs along an average north-northeast to south-southwest strike of 022.7 ± 6 in the Eastern Ranges of the Colombian Andes.

For other uses, see Usme (disambiguation).
Usme Fault
Falla de Usme
EtymologyUsme
Coordinates04°20′03.9″N 74°12′11.2″W
Country Colombia
RegionAndean
StateCundinamarca
CitiesBogotá
Characteristics
RangeEastern Ranges, Andes
Part ofAndean oblique faults
Length64.9 km (40.3 mi)
Strike022.7 ± 6
DipEast
Dip angleHigh
Displacement1–5 mm (0.039–0.197 in)/yr
Tectonics
PlateNorth Andean
StatusActive
EarthquakesPossibly historic
TypeOblique normal fault
MovementDextral
AgeQuaternary
OrogenyAndean

Etymology

The fault is named after Usme, southern locality of the Colombian capital Bogotá.[1]

Description

The Usme Fault is located in the Eastern Ranges of the Colombian Andes, south of Bogotá and extends along the western margin of the Tunjuelo River valley.[1] The fault underlies the Sumapaz Páramo.[2] The fault displaces Cretaceous and Tertiary rocks as well as Quaternary alluvial and glacial (moraine) deposits.[1]

The fault valley shows features suggesting a half-graben with a steep slope wall on the west and low-angle slope on the east. The fault forms a steep, prominent circa 40 metres (130 ft) high east-facing scarp on Cretaceous rocks that show initial development of triangular facets. The hanging valleys have Quaternary alluvial deposits on the western uplifted block. The scarp forms the western wall of a narrow and long valley. To the south of Bogotá, it appears that Pleistocene moraines are offset as recorded by east-facing well-preserved scarps about 3 metres (9.8 ft) high.[3]

See also

References
  1. Paris et al., 2000a, p.48
  2. Paris et al., 2000b
  3. Paris et al., 2000a, p.49

Bibliography

Maps
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