Interpretation of seismic profiles, earthquake fault-plane solutions, radar images, and geometry of structures suggests that two different structural styles are viable alternatives for the Putumayo basin in Colombia. An eastern domain, varying in width from 4 to 13 km, might be characterized by strike-slip faulting parallel to the Andes because it exhibits similar structures to those formed in restraining bend settings, an example is the Orito fold, the largest known oil field in the basin. Correlation of seismic reflections with wells into the Orito fold and foreland indicates a post-Miocene age for this structure. Previous interpretations of contractional dip-slip movement on Andes-parallel structures, as proposed by Portilla (1991) with faults involving basement, are also viable. A 15 km-width western domain is interpreted as a region of foreland-dipping rocks uplifted above their regional level by wedging of pre-Cretaceous (?) rocks beneath known Jurassic rocks. Above the Jurassic rocks thin-skinned deformation occurs inside of the Mesozoic and Cenozoic sedimentary cover, also in the form of wedging. Mesozoic and Paleozoic (?) rocks were injected into of a late Cretaceous-early Paleocene unit composed of shale. The western domain is truncated to the west by a major reverse fault that places Paleozoic rocks over Mesozoic and Cenozoic rocks.

Andean Structural Styles: A Seismic Atlas is a comprehensive reference illustrating the variability in structural styles and hydrocarbon traps that exist in the Andean chain. The Andean chain, stretching over more than 5,000 km (3,000 mi) from Venezuela to Argentina, contains a large number of sedimentary basins which have developed in a wide range of tectonic settings. Some of these basins are highly mature, with hydrocarbon production from Paleozoic, Mesozoic, and Cenozoic sedimentary sequences, while others are still underexplored. Andean Structural Styles: A Seismic Atlas covers topics including fold types, thrust faults, triangle zones, inversion structures, synorogenic deposits, and growth stratal geometries. These topics are illustrated by thirty-two seismic examples interpreted and uninterpreted, covering most of the Andean basins, and five chapters reviewing the structural styles of the Andes, the complexity of processing seismic in these settings, how analogue models help in the interpretation, and several outcrop analogues. This reference is invaluable to both hydrocarbon exploration of the Andes and researchers and students in the fields of exploration geology and structural geology. Also, those teaching structural geology and seismic interpretation will find a valuable resource with lots of uninterpreted seismic examples that can be used in their lectures. Includes a vast collection of high-quality, color images Features case studies covering the entirety of the Andes Mountain chain Presents high-quality seismic data that was previously only available to oil companies

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.

"AAPG Memoir 79, The Circum-Gulf of Mexico and the Caribbean, is the first volume in more than a decade to document such a wide range of research on the geology of this vast area. Of the total 44 papers, roughly two-thirds pertain to the Gulf of Mexico, with an emphasis on the Mexican portion of the basin, and to the petroliferous areas of the southern Caribbean, including Colombia, Venezuela, Cuba, and Trinidad and Tobago. The remaining papers relate to the Antilles and Central America, as well as a series of papers that address region-wide topics such as plate tectonic evolution. A significant number of papers were contributed by authors from national oil companies and universities from within the region." --AAPG.

This book provides a comprehensive overview of the geological evolution of the Northern Andes and contiguous shield areas, with a focus upon Colombia. Updated geological interpretations are supported by modern lithogeochemical, seismic, gravity and magnetic data and radiogenic isotope and radiometric age determinations. The composite data permits a detailed interpretation of the tectono-magmatic history of the Northern Andean Block, including the Andes of Colombia, northern Ecuador, western Venezuela and eastern Panamá. Tectonic reconstructions based upon characterization of more than thirty litho-tectonic and morpho-structural units, terrane assemblages and tectonic realms, and their bounding suture and fault systems, highlight the intimate and complementary Mesozoic-Cenozoic history of the Northern Andean Block and the Pacific and Caribbean Plates. The complex nature of Northern Andean assembly contrasts with ‘‘classical’’ Central Andean ‘‘Cordilleran-type’’ orogenic models. Differences render the application of typical Cordilleran-type models inappropriate for the Colombian Andes. The importance of underlying Proterozoic through mid-Mesozoic elements, in the development of Meso-Cenozoic Northern Andean orogeny-phase tectonic configurations is analyzed in the light of spatial-temporal studies and reconstructions related to basin formation, sedimentation, deformation, uplift mechanisms, structural style and magmatic evolution. The pre-Andean architecture of north western South America has played a pre-determinative role in the development of the Northern Andean orogenic system. 16 contributions analyze key stratigraphic, structural, metamorphic, magmatic and tectonic questions, and provide solutions as far as the most recent published field-based studies permit. The volume provides geological interpretations and tectonic models which contrast with repetitive theoretical proposals frequently found in the available literature.