Examinando por Materia "Cordillera Oriental"
Mostrando 1 - 5 de 5
Resultados por página
Opciones de ordenación
Publicación Análisis de procedencia sedimentaria : minerales densos y petrografía sedimentaria en las formaciones Payandé, Saldaña, Caballos y Grupo Honda, Valle Superior del Magdalena(Universidad EAFIT, 2020) Barragán Triana, Diego Fernando; Cardona Ocampo, Mariana; Beltrán Triviño, Alejandro; Semillero de investigación de Tectono-estratigrafía (STENO) de la Universidad EafitPublicación ¿Es el Escudo de Guyana la principal fuente de aporte sedimentario a la cuenca del VMM durante el intervalo Cretácico-Neógeno? implicaciones en la paleogeografía y el levantamiento de los Andes colombianos(Universidad EAFIT, 2020) Rodríguez Caicedo, Angie Karolain; Duque Carrillo, Daniel Andrés; Beltrán Triviño, Alejandro; Semillero de Tectono-EstratigrafíaDifferent tectonic processes are acting over the northern margin over the Andean Cordillera, where both the subduction of the Nazca plate, as well as the compression processes that gave rise of the tectonic inversion of the Easter Cordillera in Colombia can be highlighted. In areas like the Middle Magdalena Valley, this inversion generated several changes in the sediments accumulation system, changes that can be identify by provenance analysis. In this project the provenance analysis of Olini Group, Set Ti, Ti2 and Mesa Formation was obtain, which the outcrops are between the Middle Magdalena Valley and the western flank of the Eastern Cordillera, between the departmental limits of Boyacá and Santander. These analyzes indicates that the main areas of contribution of these formations are possibly the Central Cordillera and the Guyana Shield, but due to the high tectonic activity that occurs at the end of the Cretaceous and during the Cenozoic, sediment reworking occurred on the easter margin of Colombia associated with the uplift of the Eastern Cordillera.Publicación Los gonfoterios de Soatá, Boyacá(Universidad EAFIT, 2023) Valencia Sánchez, Samuel; Carrillo, Juan DavidProboscideans were part of the megafauna that habited South American ecosystems during the Pleistocene. Recent taxonomic revisions established that two species inhabited the continent. In Colombia, gomphothere fossils have been reported in the Andean and Caribbean regions, indicating a widespread distribution. Most remains are fragmentary however, and specific taxonomic assignations are not possible. In this study new gomphothere remains from the Soatá Formation in the Eastern Cordillera are described. According to the morphometric and anatomical features, it is proposed that the gomphothere species that inhabited the Chicamocha Canyon region during the Late Pleistocene corresponds to Notiomastodon platensis, supporting the hypothesis that Andean valleys functioned as migratory corridors for Pleistocene megafauna.Publicación Proveniencia sedimentaria de la cuenca del Catatumbo durante el cenozoico : implicaciones paleogeográficas(Universidad EAFIT, 2019) Pérez Contreras, Héctor Camilo; Valencia Arias, Cristian Andrés; Beltrán Triviño, Alejandro IvánPublicación Tierras raras durante el Campaniano-Maastrichtiano en el Valle Medio del Magdalena(Universidad EAFIT, 2025) Arbeláez Gallo, Emilio José; Betancur Guerra, Simón; Cárdenas Rozo, Andrés LeonardoThis work determines the geological processes that enabled REE enrichment in the La Renta Formation and the base of the Umir Formation in the MMV. A high-resolution stratigraphic section was measured at the La Renta Formation neostratotype (Aguablanca Creek, Lebrija, Santander), complemented with petrography, XRD, XRF, and ICP-MS analyses. Results indicate that REE enrichment in the La Renta Formation occurs in phosphorites genetically related to storms (tempestites) in a mid-ramp environment under the influence of upwelling currents, where oceanic-diagenetic capture of REE by carbonate fluorapatite (CFA) resulted in HREE enrichment (La/Yb_N≈0.64). Ce/Ce* (0.46) and Y/Ho (58.3) ratios suggest that the primary source was a metallogenically enriched ocean due to Late Cretaceous submarine magmatism. On the other hand, in the Umir Formation, enrichment occurs in a basal conglomerate with total concentrations of ΣREE+Y≈700 ppm, enriched in HREE (La/Yb_N≈0.64) and displaying the diagnostic mineral sequence: glauconite-fluorapatite-pyrite-dolomite, produced by sulfur-oxidizing bacteria. This finding reflects a second phosphogenic event in an environment distinct from the La Renta Formation, with more reducing conditions and greater terrigenous influence (Y/Ho=46.9, Eu/Eu*=1.08), which was subsequently eroded and accumulated in lenses over the Campanian–Maastrichtian unconformity. Consequently, REE contents in the La Renta Formation and the base of the Umir Formation result from prior oceanic enrichment controlled by distinct paleoenvironmental processes specific to each formation's depositional environment.