Volume 2 Quaternary Chapter 8 Neogene https://doi.org/10.32685/pub.esp.36.2019.08 Detrital U–Pb Provenance, Mineralogy, and Published online 25 November 2020 Geochemistry of the Cretaceous Colombian Back–Arc Basin Paleogene Javier GUERRERO1* , Alejandra MEJÍA–MOLINA2 , and José OSORNO3 1
[email protected] Abstract The geology of the Cretaceous Colombian back–arc basin is reviewed con- Universidad Nacional de Colombia Cretaceous sidering detrital U–Pb provenance ages, mineralogy, and geochemistry of samples Sede Bogotá Departamento de Geociencias collected from outcrop sections and wells at several localities in the core of the Eastern Carrera 30 n.° 45–03 Bogotá, Colombia Cordillera, Middle Magdalena Valley, and Catatumbo areas. The data set supports previ- 2
[email protected] ous studies indicating a basin with main grabens in the present–day Eastern Cordillera Universidad Yachay Tech Hacienda Urcuquí s/n y Proyecto Yachay Jurassic between the Guaicáramo/Pajarito and Bituima/La Salina border faults, which operated Urcuquí, Ecuador as normal faults during the Cretaceous. Limestones are common on the western and 3
[email protected] Agencia Nacional de Hidrocarburos northern sides of the basin, whereas terrigenous strata predominate on the eastern Calle 26 n.° 59–65, segundo piso and southern sides. After the Berriasian, grabens were connected by marine flooding Bogotá, Colombia during the Valanginian, with two main source areas documented by distinct element * Corresponding author Triassic and mineral contents, one in the Central Cordillera magmatic arc and the other in the Guiana Shield. Some elements present in Lower Cretaceous shales, including scan- Supplementary Information: dium, vanadium, and beryllium, are not related to the sediment supply areas for the S: https://www2.sgc.gov.co/ LibroGeologiaColombia/tgc/ basin but instead are linked to Valanginian to Cenomanian hydrothermal activity and sgcpubesp36201908s.pdf Permian dikes of gabbro, diorite, and tonalite emplaced during the main phase of extension in the basin.