Examinando por Autor "Duque-Trujillo J.F."
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Ítem Geomorphological features of the Galeras Volcani Complex(Springer International Publishing, 2015-01-01) Calvache, Marta; Duque-Trujillo J.F.Ítem Paleogene magmatism of the Maracaibo Block and its tectonic significance(Springer Verlag, 2019-01-01) Duque-Trujillo J.F.; Orozco-Esquivel T.; Sánchez C.J.; Cárdenas-Rozo A.L.One of the main northern South American geological conundrums has been to establish the tectonic relationship between Caribbean and South American plates during Mesozoic and Cenozoic times. Based on the petrogenetic interpretation of magmatic bodies within the Maracaibo block, we suggest an interplay between subduction and overthrusting tectonics in the northern part of South America during the Cenozoic. Our data show that the subduction of the Caribbean Plate beneath the South American Plate started around 65 million years ago, as is evidenced by the presence of trondhjemitic intrusions in the Santa Marta Province. Then, after a ca. 5-million-year magmatic gap, the evolution of this subduction system allowed the formation of a magmatic arc represented by the calc-alkaline Santa Marta Batholith (~56–49 Ma) and Parashi Pluton (51–47 Ma). For the interval between 50 and 25 million years, our data and compiled data point to a reduction in the tectonic activity, which is supported by relatively slow rates of cooling and uplifting in the Maracaibo block. Finally, for the period since the early Miocene, the reported uplift data, subsidence rates, and stratigraphic discordances indicate a differential uplift of the Maracaibo block, decreasing from the northwestern tip (Sierra Nevada de Santa Marta) toward the southeast (Merida Andes) and suggesting that this tectonic “reactivation” is the result of dominant overthrusting tectonics. © Springer Nature Switzerland AG 2019.Ítem Paleogene magmatism of the Maracaibo Block and its tectonic significance(Springer Verlag, 2019-01-01) Duque-Trujillo J.F.; Orozco-Esquivel T.; Sánchez C.J.; Cárdenas-Rozo A.L.One of the main northern South American geological conundrums has been to establish the tectonic relationship between Caribbean and South American plates during Mesozoic and Cenozoic times. Based on the petrogenetic interpretation of magmatic bodies within the Maracaibo block, we suggest an interplay between subduction and overthrusting tectonics in the northern part of South America during the Cenozoic. Our data show that the subduction of the Caribbean Plate beneath the South American Plate started around 65 million years ago, as is evidenced by the presence of trondhjemitic intrusions in the Santa Marta Province. Then, after a ca. 5-million-year magmatic gap, the evolution of this subduction system allowed the formation of a magmatic arc represented by the calc-alkaline Santa Marta Batholith (~56–49 Ma) and Parashi Pluton (51–47 Ma). For the interval between 50 and 25 million years, our data and compiled data point to a reduction in the tectonic activity, which is supported by relatively slow rates of cooling and uplifting in the Maracaibo block. Finally, for the period since the early Miocene, the reported uplift data, subsidence rates, and stratigraphic discordances indicate a differential uplift of the Maracaibo block, decreasing from the northwestern tip (Sierra Nevada de Santa Marta) toward the southeast (Merida Andes) and suggesting that this tectonic “reactivation” is the result of dominant overthrusting tectonics. © Springer Nature Switzerland AG 2019.Ítem Paleogene magmatism of the Maracaibo Block and its tectonic significance(Springer Verlag, 2019-01-01) Duque-Trujillo J.F.; Orozco-Esquivel T.; Sánchez C.J.; Cárdenas-Rozo A.L.One of the main northern South American geological conundrums has been to establish the tectonic relationship between Caribbean and South American plates during Mesozoic and Cenozoic times. Based on the petrogenetic interpretation of magmatic bodies within the Maracaibo block, we suggest an interplay between subduction and overthrusting tectonics in the northern part of South America during the Cenozoic. Our data show that the subduction of the Caribbean Plate beneath the South American Plate started around 65 million years ago, as is evidenced by the presence of trondhjemitic intrusions in the Santa Marta Province. Then, after a ca. 5-million-year magmatic gap, the evolution of this subduction system allowed the formation of a magmatic arc represented by the calc-alkaline Santa Marta Batholith (~56–49 Ma) and Parashi Pluton (51–47 Ma). For the interval between 50 and 25 million years, our data and compiled data point to a reduction in the tectonic activity, which is supported by relatively slow rates of cooling and uplifting in the Maracaibo block. Finally, for the period since the early Miocene, the reported uplift data, subsidence rates, and stratigraphic discordances indicate a differential uplift of the Maracaibo block, decreasing from the northwestern tip (Sierra Nevada de Santa Marta) toward the southeast (Merida Andes) and suggesting that this tectonic “reactivation” is the result of dominant overthrusting tectonics. © Springer Nature Switzerland AG 2019.Ítem Paleomagnetism and magnetic fabrics of Mio-Pliocene hypabyssal rocks of the Combia event, Colombia: tectonic implications(Akademie Ved Ceske Republiky, 2017-10-01) Piedrahita V.A.; Molina-Garza R.S.; Sierra G.M.; Duque-Trujillo J.F.; Piedrahita V.A.; Molina-Garza R.S.; Sierra G.M.; Duque-Trujillo J.F.; Universidad EAFIT. Departamento de Ciencias; Geología Ambiental y TectónicaMio-Pliocene hypabyssal rocks of the Combia event in the Amaga basin (NW Andes-Colombia), contain a deformational record of the activity of the Cauca-Romeral fault system, and the interaction of terranes within the Choco and northern Andean blocks. Previous paleomagnetic studies interpreted coherent counterclockwise rotations and noncoherent modes of rotation about horizontal axes for the Combia intrusives. However, rotations were determined from in-situ paleomagnetic directions and the existing data set is small. In order to better understand the deformational features of these rocks, we collected new paleomagnetic, structural, petrographic and magnetic fabric data from well exposed hypabyssal rocks of the Combia event. The magnetizations of these rocks are controlled by a low-coercivity ferromagnetic phase. Samples respond well to alternatingfield demagnetization isolating a magnetization component of moderate coercivity. These rocks do not have ductile deformation features. Anisotropy of magnetic susceptibility and morphotectonic analysis indicate that rotation about horizontal axes is consistently to the south-east, suggesting the need to apply a structural correction to the paleomagnetic data. The relationships between magnetic foliations and host-rock bedding planes indicate tectonic activity initiated before similar to 10 Ma. We present a mean paleomagnetic direction (declination D = 342.8A degrees, inclination I = 12.1A degrees, 95% confidence interval alpha(95) = 12.5A degrees, precision parameter k = 8.6, number of specimens n = 18) that incorporates structural corrections. The dispersion S = 27A degrees of site means cannot be explained by secular variation alone, but it indicates a counterclockwise rotation of 14.8A degrees +/- 12.7A degrees relative to stable South America. Paleomagnetic data within a block bounded by the Sabanalarga and Cascajosa faults forms a more coherent data set (D = 336.5A degrees, I = 17.4A degrees, alpha(95) = 11.7A degrees, k = 12.5, n = 14), which differs from sites west of the Sabanalarga fault and shows a rotation about a vertical axis of 20.2A degrees +/- 10.7A degrees. Deformation in the Amaga basin may be tentatively explained by the obduction of the Caas Gordas terrane over the northwestern margin of the northern Andean block. However, it can also be related to the local effects of the Cauca-Romeral fault system.Ítem The guamuéz (La Cocha) lake(Springer International Publishing, 2015-01-01) Duque-Trujillo J.F.; Hermelin, M.; Toro, G.