Structure of the Cordillera de la Costa Belt, North-Central Venezuela: Implications for plate tectronic models

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

OSTI ID:6103249

Ave Lallemant, H G; Sisson, V B; Wright, J E ^[1]

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1. Rice Univ., Houston, TX (United States)

Preliminary results of an on-going study of the Cordillera de la Costa belt between Puerto Cabello and Choroni, north-central Venezuela, indicate that the deformational history is far more complicated than expected from simple plate-tectonic models. The Cordillera de la Costa belt consists of oceanic rocks (e.g., serpentinites, amphibilites, with lenses of eclogite and blueschist) intimately intermixed with metamorphosed continental margin deposits (e.g., mica and graphite schist, quartzite, marble). Locally, large granitic (basement ) complexes of Lower Paleozoic age are included as well. In late Cretaceous time, the entire belt was involved in four synmetamorphic deformations phases (D[sub 1a] to D[sub 1d]); the first (D[sub 1a]) occurred at depths of at 35-40 km and the later ones at successively shallower depths. This deformation occurred in a subduction zone, related to right-oblique convergence of the Farallon and Atlantic plates. The most penetrative structures resulted from (all in present coordinates) north-south contraction and east-west dextral simple shear (D[sub 1b]). During an Early Tertiary ( ) event (D[sub 2]), the belt was emplaced southward onto the South American continental margin. Subsequent deformational structures (D[sub 3]) resulted in cross folds and faults (with small pull-apart basins) which are consistent with the eastward passage of the Caribbean past the South American plate.

• OSTI ID: 6103249
• Report Number(s): CONF-930306-; CODEN: AABUD2
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:2; Conference: International congress of the American Association of Petroleum Geologists (AAPG), Caracas (Venezuela), 14-17 Mar 1993; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
GEOLOGIC STRUCTURES
DEFORMATION
SOUTH AMERICA
PLATE TECTONICS
VENEZUELA
GEOLOGIC HISTORY
CONTINENTAL MARGIN
CRETACEOUS PERIOD
GRAPHITE
MARBLE
MICA
SERPENTINITES
CARBON
DEVELOPING COUNTRIES
ELEMENTAL MINERALS
ELEMENTS
GEOLOGIC AGES
LATIN AMERICA
MESOZOIC ERA
METAMORPHIC ROCKS
MINERALS
NONMETALS
ROCKS
SILICATE MINERALS
TECTONICS
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences