Regional provenance from southwestern Colombia fore-arc and intra-arc basins: implications for Middle to Late Miocene orogeny in the Northern Andes Sebasti an Echeverri, 1 Agustı´n Cardona, 2 Andr es Pardo, 1 Gaspar Monsalve, 3 Victor A. Valencia, 4 Carlos Borrero, 1 Sebasti an Rosero 1 and Sergio L opez 5 1 Instituto de Investigaciones en Estratigrafı´a-IIES, Universidad de Caldas, Calle 65 No. 26-10, Manizales, Colombia; 2 Departamento de Procesos y Energı´a, Facultad de Minas, Universidad Nacional de Colombia, Carrera 80 No 65 – 223, Medellı´n, Colombia; 3 Departamento de Geociencias y Medio Ambiente, Facultad de Minas, Universidad Nacional de Colombia, Carrera 80 No 65 – 223, Medellı´n, Colombia; 4 School of the Environment, Washington State University, Pullman, WA, USA; 5 Agencia Nacional de Hidrocarburos-ANH, Avenida Calle 26 No. 59 - 65 Piso 2, Bogota ´, Colombia ABSTRACT Andean orogenic processes controlled the spatial and tem- poral distribution of the magmatic and sedimentary record. This contribution integrates new U/Pb zircon ages, heavy mineral analyses and biostratigraphic constraints from the Neogene sedimentary record of the fore-arc and intra-arc basins and volcano-plutonic rocks of southwestern Colom- bia, to reconstruct these orogenic processes. The results reveal continuous arc magmatism since the Late Oligocene, with a major post-Middle Miocene magmatic peak and exhumation. When integrated with other geological constraints, the tectonic evolution of the margin includes Eocene-Oligocene oblique convergence with limited mag- matic activity, followed by the initiation of a Late Oligo- cene-Early Miocene arc that migrated to the east in the Middle Miocene, when it experienced a major increase in magmatic activity, crustal deformation, exhumation and thickening. This orogenic evolution is related to the shallowing of the slab dip due to the subduction of the Neogene Nazca Plate. Terra Nova, 00, 000–000, 2015 Introduction The Andean orogeny results from the subduction of the Pacific oceanic plate under the South American con- tinent, and is influenced by thermal weakening of the crust due to arc magmatism, changes in the dip of the subducting slab and variations in the absolute motion of the upper plate (Pennington, 1981; Jordan et al., 1983; Russo and Silver, 1996; Haschke et al., 2002; Kay et al., 2005; Oncken et al., 2006; DeCelles et al., 2009; Ramos and Folguera, 2009; Martinod et al., 2010). Older sutures, extensional struc- tures, climate and long-term evolu- tion of the mantle may imprint a particular characteristic to each of the orogenic episodes (Ramos et al., 2002; Lamb and Davis, 2003; Ra- mos, 2009; Capitanio et al., 2011; Mora et al., 2013). Although basin, deformational and magmatic effects related to Cenozoic Andean tectonics have recently been discriminated along different seg- ments of the Colombian Andes (Mora et al., 2008; Parra et al., 2009; Bayona et al., 2011, 2012; Vil- lag omez and Spikings, 2013), the details of the post-Eocene orogenic controls and the along-strike varia- tions in style, mechanisms and timing are still controversial. Proposed models for the Andean orogeny in the Northern Andes include: Late Neogene initiation of flat-slab subduction (Ramos, 2009), Oligoceone-Miocene changes in plate convergence directions and rates, fast westward drift of South America, the collision of the Panama block, and the subduction of the Carnegie ridge (Duque-Caro, 1990; Taboada et al., 2000; Parra et al., 2009; Restrepo- Moreno et al., 2009; Ramos, 2010; Sch€ utte et al., 2010; Farris et al., 2011; Mora et al., 2013; Villag omez and Spikings, 2013). In this study, we present 2192 new U/Pb detrital zircon ages, 59 heavy mineral analyses and new biostratigraphical constraints from Neogene outcrops and wells in the scarcely known fore-arc and intra- arc sedimentary basins of southwest- ern Colombia (Fig. 1); this detrital record is used as a proxy to under- stand changes in magmatic fluxes and exhumation of the margin (Cawood et al., 2012; Barth et al., 2013). When these results are integrated with pub- lished subsidence (L opez, 2009; Ech- everri et al., 2012), mantle petrology (Weber et al., 2002; Rodrı´guez-Var- gas et al., 2005) and thermochrono- logical data (Villag omez and Spikings, 2013) and crustal thickness estima- tions for southwestern Colombia (Poveda et al., 2015), the timing and controls of Neogene Andean orogeny in this region can be evaluated. The proposed orogenic model suggests that this segment of the margin experi- enced a Late Miocene magmatic flare- up, exhumation and shortening with associated underthrusting of the retro-arc below the main arc. This event was associated with a shallow- ing of the subduction angle. Tectonic configuration The modern boundary between the Nazca plate and the South American Correspondence: Sebasti an Echeverri, Instituto de Investigaciones en Estratig- rafı´a-IIES, Universidad de Caldas, Calle 65 No. 26-10, Manizales, Colombia. Tel.: +57 3148542880; e-mails: juansebasechev- erri@gmail.com; sebastian.echeverri@usp. br © 2015 John Wiley & Sons Ltd 1 doi: 10.1111/ter.12167