Examinando por Autor "Restrepo, J.C."

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    Cartagena Bay (Colombia): Superficial sediments distribution and sedimentary environments
    (UNIV CATOLICA DE VALPARAISO, 2013-01-01) Restrepo, J.C.; Franco, D.; Escobar, J.; Correa, I.D.; Otero, L.; Gutiérrez, J.; Universidad EAFIT. Departamento de Geología; Ciencias del Mar
    We studied the spatial distribution and textural characteristics of 234 surface sediment samples from the Bay of Cartagena, Colombia, to understand sedimentation processes over the last few decades. We used three discriminant functions to characterize depositional environments and to differentiate among: (i) beach deposits and sediments of high-energy, shallow marine environments, (ii) fluvial deposits and sediments of shallow marine environments, and (iii) fluvial deposits influenced by turbidity currents. The predominant sediment type is a medium-size (5.35 ± 1.2 f), poorly sorted (s = 1.63 ± 0.8) mud, with a noticeable asymmetry (Sk = -0.052 ± 0.2) and kurtosis (k) of 0.84 ± 0.4. There were two main superficial sediments types in the Bay of Cartagena: (1) sediments of high-energy, shallow marine environments with high fluvial influence, and (2) turbidity current deposits with high fluvial influence. Sediments with the lowest sand content (<5%) are located along a latitudinal axis running from the Dike Channel prodelta to the western end of Tierrabomba Island. The CaCO3 content of the sediments is <10%. Autogenous calcareous sediments are covered by fine terrigenous sediment transported through the Dike Canal, which has a more active and dominant role in the Bay's sediment deposition than previously reported.
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    Factors Influencing the Distribution and Characteristics of Surface Sediment in the Bay of Cartagena, Colombia
    (COASTAL EDUCATION & RESEARCH FOUNDATION, 2017-01-01) Restrepo, J.C.; Escobar, J.; Otero, L.; Franco, D.; Pierini, J.; Correa, I.; Universidad EAFIT. Departamento de Geología; Ciencias del Mar
    This study evaluated patterns of coastal sediment movement and deposition under different seasonal conditions (warm and cold phases of the El Nino-Southern Oscillation [ENSO] and normal conditions) in Cartagena Bay, Colombia. A calibrated numerical model (MOHID modeling system) was applied to assess the spatial distribution of sediments transported by the Canal del Dique to the bay and studied the spatial distribution and major textural characteristics of 234 surface sediment samples. Currents in the Bay of Cartagena are controlled primarily by the strength and direction of the wind. Model results show major sediment deposition in the southern sector of the bay during the dry season. More homogenous spatial distribution of sediments throughout the Bay of Cartagena occurs with an increase in river inputs from the Canal del Dique. These patterns were enhanced or weakened, respectively, by cold and warm phases of the ENSO. Predominant sediments were medium size (phi = 5.35 +/- 1.2), poorly sorted (sigma = 1.63 +/- 0.8), with notable asymmetry (Sk = -0.052 +/- 0.2) and kurtosis (k = 0.84 +/- 0.4). Sediments with lower sand content (<5%) are located along a latitudinal axis from the Canal del Dique delta to the western end of the island of Tierrabomba. CaCO3 content of the sediments is <10%. Water and sediment flow, controlled by the Canal del Dique, has favored the transport and deposition of poorly sorted, symmetric, and mesokurtic mud in most of the Bay of Cartagena. As a result, autogenous calcareous sediments have been covered by fine terrigenous sediments that were delivered via the Canal del Dique. Thus, the channel plays a more prominent role in sediment transport and deposition in the Bay of Cartagena than thought previously.