Print this pageTectonic Controls from Middle Eocene to Recent Stratigraphic Sequences Along the Guajira Margin of Northern Colombia
Eleine M. Vence1, Paul Mann1, and Alejandro Escalona2
1University of Texas at Austin, Austin, TX
2Geology, University of Stavanger, Stavanger, Norway
The basement of the Guajira margin of Colombia is underlain by the 100-125-km-wide Great Arc of the Caribbean that continues eastward to the Leeward Antilles arc and southward as the onshore San Jacinto belt of Colombia. The Great Arc area forms a characteristic elongate belt of Cretaceous igneous and metamorphic rocks based on several wells drilled in the region. Well data indicates that the crest of the Great Arc trend was subaerial from Eocene to Early Miocene but became buried by marine sediments starting in Middle Miocene time. Deformation of the elongate Caribbean arc trend has controlled the deposition of eight Late Eocene to Recent marine stratigraphic sequences that have been mapped using a total of 2400 km of seismic reflection data and 12 wells. Deformation events affecting the sequences can be divided into two main phases: 1) Middle Eocene to Late Oligocene rifting of the Great Arc in an east-west direction produced half-grabens in the northern part of the study area containing two syn-rift sequences; in the southern part of the area this phase is expressed as right-lateral Oligocene strike-slip faulting along the east-west-striking Cuisa and Dorado faults; a ~200 km2 pull-apart basin along the Cuisa fault forms a deep, asymmetrical basin; 2) Early Miocene to Pliocene post-rift subsidence and downslope gravity-driven normal faulting control six marine sequences; normal fault planes generally dip seaward into deeper water and are controlled by the original steep flanks of the Great Arc. Hydrocarbon prospects include thermogenic and biogenic gas in Eocene-Oligocene syn-rift sequences 1 and 2 and biogenic gas near the base of prograding clinoforms of the Miocene-Recent post-rift sequences 3 through 6.
AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas