FetKin: Coupling kinematic restorations and temperature to predict thrusting, exhumation histories, and thermochronometric ages Ariel Almendral, Wilmer Robles, Mauricio Parra, Andrés Mora, Richard A. Ketcham, and Michael Raghib ABSTRACT FetKin is a C++ program for forward modeling thermochrono- logical ages on a two-dimensional geological cross section. Modeled ages for various thermochronometers are computed from time–temperature histories that result from coupling the modeled kinematics of deformation obtained from commercial software for balanced reconstructions (2DMove) and a finite element computation of temperatures. Additional capabilities include the ability to accommodate (1) a smooth change of topological relief; (2) the influence of variation in rock physical properties; and (3) multikinetic modeling of fission-track ages and length distri- butions, as well as apatite and zircon (U-Th)/He and muscovite 40 Ar∕ 39 Ar systems. A joint first-order analysis of the impact of erosion parameters and material properties improves age predic- tions and allows for a more complete analysis of observed cooling ages based on their modeled thermal histories. Thus, this paper presents a new software tool that has been developed as a basic support for the methodological approach used to build the kinematic restorations shown in this volume, which are the basic input for petroleum systems modeling and prediction in the Colombian Eastern Cordillera and Llanos foothills basin. INTRODUCTION Knowledge about the timing of deformation of geological struc- tures is critical to understanding virtually all geological processes Copyright ©2015. The American Association of Petroleum Geologists. All rights reserved. Manuscript received August 1, 2011; provisional acceptance December 10, 2012; revised manuscript received August 2, 2013; revised manuscript provisional acceptance October 2, 2013; 2nd revised manuscript received March 7, 2014; final acceptance July 7, 2014. DOI: 10.1306/07071411112 AUTHORS Ariel Almendral ∼ Instituto Colombiano del Petróleo, Piedecuesta, Santander, Colombia; present address: Norsk Regnesentral/Norwegian Computing Center, P.O. Box 114, Blindern, NO-0314 Oslo, Norway; Ariel.Almendral.Vazquez@nr.no; aalmendral@gmail.com Ariel Almendral is a senior researcher at Norwegian Computing Center in Oslo, Norway, where he develops geostatistical software for the O&G industry. He has also contributed to the development of the Petrel framework in the area of three-dimensional geology and modeling. His Ph.D. work from the University of Oslo (2005) dealt with numerical computation of financial derivatives. Wilmer Robles ∼ Instituto Colombiano del Petróleo, Piedecuesta, Santander, Colombia; wilmerangel@gmail.com Wilmer Robles is an external consulting geophysicist at Instituto Colombiano del Petróleo-Ecopetrol, with an M.Sc. degree in geophysics from the Universidad Nacional de Colombia. His interests include fault-bend folding, thermochronology, and the acquisition, processing, and interpretation of geophysical data. Mauricio Parra ∼ Instituto Colombiano del Petróleo, Piedecuesta, Santander, Colombia; Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78759; m.parra@iee.usp.br Mauricio Parra is an external research consultant for Instituto Colombiano del Petróleo-Ecopetrol. He received a Ph.D. in geosciences from the University of Potsdam in 2009, followed by a postdoctoral stay at the Department of Geosciences, University of Texas at Austin. He has worked in the tectonic evolution of Colombian orogens using thermochronometry and basin analysis. Andrés Mora ∼ Instituto Colombiano del Petróleo, Piedecuesta, Santander, Colombia; andres.mora@ecopetrol.com.co Andres Mora is a senior geologist at Instituto Colombiano del Petróleo-Ecopetrol. He AAPG Bulletin, v. 99, no. 8 (August 2015), pp. 1557–1573 1557