About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
AAPG Bulletin
Abstract
AAPG Bulletin, V.
2006. The American Association of Petroleum Geologists. All rights reserved.
Tectonic controls of the right-lateral Burro Negro tear
fault
on Paleogene structure and stratigraphy, northeastern Maracaibo Basin
![Previous Hit](/data/images/arrow_left.gif)
![Next Hit](/data/images/arrow_right.gif)
Alejandro Escalona,1 Paul Mann2
1Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759; [email protected]
2Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759; [email protected]
ABSTRACT
The northeastern Maracaibo Basin in western Venezuela was deformed by Paleogene thrusting and an associated tear fault
(Burro Negro right-lateral strike-slip
fault
zone), related to Paleogene oblique collision between the Caribbean and South American plates. Two different tectonic models have been previously proposed for the thick Paleogene depocenter located along the northeastern margin of the Maracaibo Basin. The first model proposes that the depocenter is a foreland basin controlled by southwestward-directed overthrusting during a late Paleocene–middle Eocene oblique collision between the Caribbean and South American plates. The second model, supported by data presented in this study, proposes that the asymmetric Paleogene Maracaibo sedimentary wedge was controlled by strike-slip displacement along a right-lateral tear
fault
, separating southeast-directed thrust sheets to the east (Lara nappes) from a more stable platform area to the west (Maracaibo Basin).
Regional seismic lines recorded to 5 s two-way traveltime reveal the structure of the asymmetric Paleogene depocenter in the northeastern part of the Maracaibo Basin. The approximately 100-km (62-mi)-long Burro Negro fault
is a right-lateral strike-slip
fault
separating less deformed, inner- to outer-shelf rocks of the western Maracaibo Basin from highly deformed, deep-marine rocks of the eastern Maracaibo Basin. Seismic lines northeast of the Burro Negro
fault
zone show elongate, subsurface basins bounded by partially inverted reverse and strike-slip faults filled with about 3 km (1.8 mi) of Oligocene and Miocene clastic marine sedimentary rocks. Structural highs of Eocene rocks are characterized at depth on seismic reflection lines by chaotic seismic reflections that underlie the more coherently stratified Oligocene and Miocene subbasins. We interpret these structural highs as steeply dipping
fault
zones and shale diapirs activated during Eocene–Oligocene oblique plate convergence.
The geology and overall structural configuration of the northeastern Maracaibo Basin and the Burro Negro fault
zone support its origin as a right-lateral tear
fault
. In our model, the Burro Negro
fault
zone accommodated southeastward migration of the thrust front in the deep-water area east of the
fault
in the present-day Falc
n region. The Paleogene clastic wedge of the Maracaibo Basin exhibits many common features of a classic foreland basin, including onlap onto an arch or forebulge located near the center of the present-day Lake Maracaibo. This paleogeographic coincidence of the Burro Negro
fault
zone and the Maracaibo shelf edge suggests that the paleotrend of the South American passive margin prior to collision was serrated in map view. West-to-east migration of the Caribbean–South America oblique collision formed progressively younger, parallel tear faults to the east of the Maracaibo Basin that may have formed by the same tectonic process as the Burro Negro
fault
zone.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |
AAPG Member?
Please login with your Member username and password.
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].