Browsing by Subject "Condiciones palaeoambientales"

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    Biomarcadores lipídicos y contaminación por metales en el registro del holoceno de la bahía de Cartagena (sureste de España): historia ambiental natural y antropogénica combinada en la Época Púnica y Romana
    (Universidad de Murcia, 2026-06-03) Torres, Trinidad; Sánchez-Palencia, Yolanda; Ros Sala, Milagros; Ortiz, José E.; López-cilla, Ignacio; Galán, Luis A.; Manteca, Ignacio; Rodríguez-Estrella, Tomás; Blázquez, Ana; Ramallo Asensio, Sebastián Federico; Sin departamento asociado; Cutillas Victoria, Benjamín; Ramallo Asensio, Sebastián Federico
    The paleoenvironmental conditions of Cartagena Bay during the Holocene were reconstructed through a multidisciplinary study with the main goal of identifying natural variations and anthropogenic processes in this coastal area. A total of 119 samples were collected for amino acid racemization dating, 3 for radiocarbon dating, and four sets of 80 samples each for sedimentological and paleontological analysis, mineralogical content, biomarker analysis, and trace element quantification. Two natural scenarios were identified based on variations in n-alkane indices and paleobiological content. The first period (6650–5750 cal yr BP) was characterized by the development of euhaline marine conditions with significant contributions of aquatic macrophytes and high biodiversity. After a hiatus, the area underwent a significant change, becoming a sparsely populated brackish marsh environment with increasing terrestrial plants, and possible periods of emergence with a greater presence of terrestrial gastropods (3600–300 cal yr BP). By combining trace element abundance and stanol distribution, this study also provides a novel approach to identifying the predominant influence of anthropogenic factors over the last three millennia on the coastal record of Cartagena Bay. The findings confirmed that lead mining and metallurgy began during the Bronze Age, with considerable contributions of this metal to the atmosphere during the Phoenician, Punic, and particularly Roman periods, compared to the Middle Ages. Copper and zinc pollution was also observed during the Punic and Roman periods and was first documented in the Middle Ages. In addition, fecal stanols were found, such as coprostanol, derived mainly from humans, and 24-ethylcoprostanol from herbivores, indicating for the first time a continuous presence of human populations and a significant contribution of pollution from 3600 cal yr BP, being greater at the end of the Bronze Age and during the Phoenician, Punic and Roman periods than during Late Antiquity and the Middle Ages, when an intense process of urban regression is detected in the city.
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    El registro Pleistoceno y Holoceno de la cuenca de Mazarrón (sureste de España)
    (Universidad de Murcia, 2026-06-03) Torres, Trinidad; Ortiz, José E.; Sánchez-Palencia, Yolanda; Ros Sala, Milagros; Navarro Hervás, Francisca; López-Cilla, Ignacio; Galán, Luis A.; Ramallo Asensio, Sebastián Federico; Rodríguez-Estrella, Tomás; Blázquez, Ana; Sin departamento asociado; Cutillas Victoria, Benjamín; Ramallo Asensio, Sebastián Federico
    The evolution of the Mazarrón Basin during the Pleistocene and Holocene is reconstructed. Nine core samples drilled by the University of Murcia were studied with the objectives of: 1) defining the chronological framework; 2) reconstruction of the paleoenvironmental conditions; and 3) establishing its relationship with recent tectonics. A total of 158 samples were recovered for amino acid racemization dating, 4 for radiocarbon dating, 332 for sedimentological and paleontological analysis, and 110 for mineralogical analysis. These data allowed for the elucidation of the evolutionary phases of the Mazarrón Basin paleolandscape, a fault-controlled graben affected by several faults, primarily the Las Moreras and Rella faults. The ages of the sedimentary record and facies correlation indicate that the Las Moreras Fault controlled sedimentation during Marine Isotope Stage (MIS) 7, while the Rella Fault was highly active during the Middle Holocene. During MIS 7, a brackish lagoon developed in the western area, overlying alluvial fan deposits. Subsequently, the area was uplifted, becoming exposed to erosion. Activity along the Rella Fault allowed sedimentation in the western part of the Mazarrón Basin during the Middle Holocene, while in the Late Holocene, sedimentation occurred in the eastern part. The Holocene transgression resulted in a temporarily floodable marshland inland, with varying salinity levels, from brackish to euhaline. Along the seafront, marine influence was evident but not dominant. Thus, during the Holocene, the Mazarrón Basin ranged from brackish to highly euhaline, with variable biological diversity linked to a close and probably discontinuous connection with the sea, restricted circulation, and long renewal times, reflected in the significant presence of halite. The record ended with recent alluvial/anthropogenic sediments.