Subsurface mapping and 3D flexural modeling of the Putumayo foreland basin, Colombia

The Putumayo foreland basin (PFB) is located in southernmost Colombia and forms a 250-Kmlong segment of the 7000-Km-long corridor of Late Cretaceous-Cenozoic foreland basins formed by the eastward thrusting of the Andean mountain chain over Precambrian rocks. The current daily production of the Putumayo basin is ~90K BOPD of 15-35° API oil and 300K BOPD of 20-35º API oil in the contiguous Maranon foreland basin to the south, in Ecuador. This study uses ~4000 Km of 2D seismic data tied to 28 exploratory wells to describe the structure and stratigraphy of the basin. The PFB is located adjacent to the NNE-trending Colombian Andes that have been influenced by the oblique and shallow subduction of the Carnegie Ridge starting 8 Ma. Based on mapping of the subsurface of the PFB and comparison with published works from the southward continuation of the PFB into Peru and Ecuador, three main across-strike, structural zones, and five tectonosequences of the PFB are described based on seismic interpretations. The structural zones of the PFB include: 1) the 20-Km-wide, Eastern structural zone closest to the Andean mountain front characterized by inversion of older, Jurassic half-grabens during the late Miocene; 2) the 45-Km-wide, Central structural zone characterized by moderately-inverted Jurassic half-grabens; and 3) the 120-Km-wide, Eastern zone characterized by the 90-Km-wide, N-S trending Caquetá arch with a few slightly inverted normal faults at its crest. The five, mainly clastic tectonosequences of the PFB include: 1) pre-foreland basin Early Cretaceous sedimentary rocks; 2) the Late Cretaceous-Paleocene foreland basin deposits; 3) the Eocene foreland basin deposits related to the early uplift of the Eastern Cordillera; 4) underfilled foreland basin deposits of the Oligocene-Miocene age; 5) overfilled foreland basin of the Plio-Pleistocene age. I used 3D flexural modeling to identify the present-day tectonic elastic thickness (Te) values for the lithosphere below PFB, in order to model the location of the sedimentary-related and tectonically-related forebulges in PFB units from the Cretaceous to Oligocene. This analysisshows two pulses of rapid, foreland-related subsidence during the Late Cretaceous-early Paleocene and the Oligocene-Miocene. Despite present-day oblique thrusting of the mountain front, the PFB basement flexure reveals a tectonic forebulge located in the Eastern structural zone that acts as the updip limit for most hydrocarbons found in the basin.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Geology

Grantor

University of Houston

Year dc:date.issued

2013

Author dc:creator

• Pachon-Parra, Luis F. 1981-

Advisor dc:contributor.advisor

• Mann, Paul

Committee members dc:contributor.committeemember

• Van Wijk, Jolante W.
• Londono, John

• Flexural modeling
• Putumayo basin
• Evolution
• Tectonosequences

Statement dc:rights

• The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/10657/1063

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/1063