U-Th-Pb Detrital zircon geochronology of the Gualanday Group and its tectonic implications

"An integrated analysis of detrital zircon geochronology, clast counting, trace element concentration in zircons and zircon typology was done to get an understanding of the Gualanday Group provenance. Detrital zircon geochronology applied to the Gualanday Group sandstones provide accurate ages of the sources that fed this late Eocene - Paleocene molasse. The main peaks obtained are Precambrian, Jurassic, early and late Cretaceous. Other minor peaks of Triassic and Permian age were also identified. Clast counting gave a consent on which Gualanday Group conglomerate was sampled for this study, which were the Doima (upper) and Chicoral (lower) Formations. The trace element analysis on zircons were applied using REE diagrams, U vs. Yb, U/Yb vs. Hf and U/Yb vs. Y discrimination diagrams. This data, integrated with a typology analysis of the zircons according to their age, gave us crucial information on the type of rock in which the zircon has crystallized in and the sedimentological process that it has been through. The analysis showed that the sources of the Gualanday Group were mainly granitoid. The early Cretaceous sources are discussed and interpreted as Mariquita Stock; late Cretaceous sources are interpreted as Antioquia Batholith; Jurassic as Ibagué Batholith and/or Saldaña formation; Permo-Triassic as anatexis granitoids in Cajamarca Complex, such as Stock del Buey; Precambrian as the redeposited zircons (from the Cretaceous sedimentary cover) that chrystallized in the Greenvillian and Panafrican orogenies and are par of the Guyana Shield and Amazonian Craton. As a result, a palinspastic reconstruction map for the late Eocene - Oligocene is proposed based on the results of this study and from other authors. In this model the tectonic blocks situated west of the Upper Magdalena Valley, in which the Antioquia Batholith is, are in more meridional latitudes."--Tomado del Formato de Documento de Grado.

• Autores: Muñoz Granados, María Daniela
• Tipo de recurso: Trabajo de grado de pregrado
• Fecha de publicación: 2019
• Institución: Universidad de los Andes
• Repositorio: Séneca: repositorio Uniandes
• Idioma: eng
• OAI Identifier: oai:repositorio.uniandes.edu.co:1992/45331
• Acceso en línea: http://hdl.handle.net/1992/45331
• Palabra clave: Geocronometría; Relieve terrestre; Paleontología estratigráfica; Geociencias; Física
• Rights: openAccess
• License: http://creativecommons.org/licenses/by-nc-sa/4.0/