A structural interpretation of the Southwestern Venezuelan Andes

Conference · Mon Feb 01 04:00:00 EST 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6102180

Testamarck, J S ^[1]

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1. Maraven S.A., Caracas (Venezuela)

An interpretation of the structural evolution of the southwestern Venezuelan Andes is presented, based primarily on analysis of radar and Landsat images, and supported by field mapping and seismic profiles acquired in 1987-1991 over the northwestern flank of the Andes. The Andean core is interpreted as a collage of basement tectonic blocks which behaved independently during a Jurassic block-faulting event, upon which was superimposed northwester-vergent overthrusting in Miocene-Pliocene times. The resulting structural style is an imbricate series of thrust slices, each comprising pre-Cretaceous basement and its sedimentary cover, and displated tend of kilometers from their original position. The northwestern Andean flank between Rio Chama and La Fria is interpreted as a complex block bounded in the southeast by the Rio Mocoties Fault, which is probably very similar to the frontal thrusts of the Andes but deeper and with a stronger surface expression. The dominant structural style of the Andean flank in this sector is a monocline dipping northwest towards the foreland, with shortening increasing to the northeast towards the Rio Chama-Rio Nucujepe region, where overthrusts are more prominent. Farther southwest along the Andean front, between Rio La Grita and Santo Domingo, at the southwestern extreme of the Venezuelan Andes, the structural style is dominated by a system of northwest-southeast left-lateral faults, such as the fault complexes of Bramon, Rio Uribante and La Grita, forming a series of parallel structural blocks which are subdivided into smaller blocks by minor northeast-southwest faults.

• OSTI ID: 6102180
• Report Number(s): CONF-930306--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 77:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
ANDES
BASEMENT ROCK
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FORMATIONS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
GEOMORPHOLOGY
GEOPHYSICAL SURVEYS
JURASSIC PERIOD
LANDSAT SATELLITES
LATIN AMERICA
MAPPING
MATHEMATICS
MEASURING INSTRUMENTS
MESOZOIC ERA
MIOCENE EPOCH
MOUNTAINS
ORIGIN
PLIOCENE EPOCH
RADAR
RANGE FINDERS
SATELLITES
SEDIMENTATION
SEISMIC SURVEYS
SOUTH AMERICA
SURVEYS
TECTONICS
TERTIARY PERIOD
TOPOLOGY
VENEZUELA