@article{WeberCardonaValenciaetal.2011,
  author    = {Weber, Marion and Cardona, A. and Valencia, V. and Altenberger, Uwe and Lopez-Martinez, M. and Tobon, M. and Zapata, Sebastian Henao and Zapata, G. and Concha, A. E.},
  title     = {Geochemistry and geochronology of the Guajira Eclogites, northern Colombia evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc},
  series = {Geologica acta},
  volume    = {9},
  journal   = {Geologica acta},
  number    = {3-4},
  publisher = {Facultat de Geologia, Divisio III, Ci{\`e}ncies Experimentals i Matem{\`a}tiques, Universitat de Barcelona},
  address   = {Barcelona},
  issn      = {1695-6133},
  doi       = {10.1344/105.000001740},
  pages     = {425 -- 443},
  year      = {2011},
  abstract  = {The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive island-arc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. Ar-40-Ar-39 ages of 79.2 +/- 1.1Ma and 82.2 +/- 2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian.},
  language  = {en}
}
@article{LeonCardonaMejiaVelezetal.2019,
  author    = {Le{\´o}n, Santiago and Cardona, Agust{\´i}n and Mejia Velez, Dany and Botello, G. E. and Villa, V{\´i}ctor and Collo, Gilda and Valencia, Victor A. and Zapata, Sebastian Henao and Avellaneda-Jimenez, D. S.},
  title     = {Source area evolution and thermal record of an Early Cretaceous back-arc basin along the northwesternmost Colombian Andes},
  series = {Journal of South American earth sciences},
  volume    = {94},
  journal   = {Journal of South American earth sciences},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0895-9811},
  doi       = {10.1016/j.jsames.2019.102229},
  pages     = {16},
  year      = {2019},
  abstract  = {Identifying the provenance signature and geodynamic setting on which sedimentary basins at convergent margins grow is challenging since they result from coupled erosional and tectonic processes, which shape the evolution of source areas and the stress regime. The Early Cretaceous evolution of the northern Andes of Colombia is characterized by extensional tectonics and the subsequent formation of a marginal basin. The Abejorral Formation and coeval volcano-sedimentary rocks are exposed along the western flank and axis of the Central Cordillera. They comprise an Early Cretaceous transgressive sequence initially accumulated in fluvial deltaic environments, which switched towards a deep-marine setting, and are interpreted as the infilling record of a marginal back-arc basin. Available provenance data suggest that Permian-Triassic metamorphic and less abundant Jurassic magmatic rocks forming the basement of the Central Cordillera sourced the Abejorral Formation. New detailed volcanic and metamorphic lithics analyses, conventional and varietal study of heavy minerals, detrital rutile mineral chemistry, allowed us to document changes in the source areas defined by the progressive appearance of both higher-grade and more distal low-grade metamorphic sources, which switched from pelitic to dominantly mafic in composition. Crystallochemical indexes of clay minerals of fine-grained rocks of the Abejorral Formation suggest that samples located close to the Romeral Fault System show characteristics of low-medium P-T low-grade metamorphism, whereas rocks located farther to the northeast preserve primary diagenetic features, which suggest a high heat-flow accumulation setting. We interpret that the Abejorral Formation records the progressive unroofing of the Central Cordillera basement that was being rapidly exhumed, as well as the incorporation of distal subduction-related metamorphic complexes to the west in response either to the widening of extensional front or the reactivation of fault structures on the oceanward margin of the basin. Although the deformational record of the Abejorral Formation would have resulted from over-imposed episodes, our new geochronological constraints suggest that this sedimentary sequence must have been deformed before the Paleocene due to the presence of arc-related intrusive non-deformed magmatic rocks with a crystallization age of ca. 60 Ma.},
  language  = {en}
}