517 Copyright ©2015 by The American Association of Petroleum Geologists. DOI:10.1306/13531948M1083651 19 Tectonostratigraphic Evolution of the Northern Llanos Foreland Basin of Colombia and Implications for Its Hydrocarbon Potential Henry Campos 1 Shell Exploration and Production Company, 150 N. Dairy Ashford, Houston, Texas 77079, U.S.A. (e-mail: hmcamposa@yahoo.com) Paul Mann Department of Earth and Atmospheric Sciences, College of Natural Sciences and Mathematics, University of Houston, 3507 Cullen Blvd., Houston Texas 77004, U.S.A. (e-mail: pmann@uh.edu) ABSTRACT The Llanos Basin of Colombia is located along the eastern fank of the Andes in northern South America. The basin covers an area of approximately 194,000 km 2 and it is drained toward the east and northeast by the Arauca, Meta, Casanare, and Vichada Rivers and their tributaries that join the Orinoco River. Petroleum exploration activity in this basin began with the drilling of the frst well in 1944. Since then, two oil giants (Cano Limon and Castilla), three major oil felds (Rubiales, Apiay, and the Tame Complex), and more than 50 minor oil- felds have been discovered, representing 1500 MBOE of cumulative production and esti- mated remaining reserves of more than 3050 MBOE. These hydrocarbon volumes make the Llanos Basin very prospective for future giant- to medium-size feld discoveries, for which a complete understanding of the basin’s geologic evolution is necessary. Key factors in the petroleum potential of the Llanos Basin include the deposition of Cretaceous marine source rocks that were deeply buried and matured and multiple phases of orogeny that generated numerous structural and stratigraphic traps and pathways for oil migration. The main aim of this study is to provide an overview of the tectonostratigraphic evolution of the northern and central parts of the Llanos Basin, based on previously published information and our own seismic interpretations and fexural modeling of the foreland basin. Campos, Henry and Paul Mann, 2015, Tectonostratigraphic evolution of the Northern Llanos Foreland Basin of Colombia and implications for its hydrocarbon potential, in C. Bartolini and P. Mann, eds., Petroleum geology and potential of the Colombian Caribbean Margin: AAPG Memoir 108, p. 517–546. 1 Previous Address: Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, 2305 Speedway, Stop C1160, Austin, Texas 78712, U.S.A.