https://hdl.handle.net/10481/22929 2026-04-18T20:24:14Z 2026-04-18T20:24:14Z Carrión-Torrente, Álvaro Lobo Sánchez, Francisco José Puga Bernabeu, Ángel Mendes, Isabel Lebreiro, Susana García, Marga Van Rooij, David Luján, María Reguera, María Isabel Antón, Laura https://hdl.handle.net/10481/93531 2024-07-28T18:28:08Z

Episodic postglacial deltaic pulses in the Gulf of Cadiz: implications for the development of a transgressive shelf and driving environmental conditions Carrión-Torrente, Álvaro; Lobo Sánchez, Francisco José; Puga Bernabeu, Ángel; Mendes, Isabel; Lebreiro, Susana; García, Marga; Van Rooij, David; Luján, María; Reguera, María Isabel; Antón, Laura The postglacial sea-level rise after the Last Glacial Maximum provided ideal conditions to study the transgressive sedimentary response to sudden shelf flooding driven by different rates of sea-level rise. In this study, a high-resolution seismic stratigraphic interpretation and sedimentological analysis were conducted on data from the northern Gulf of Cadiz continental shelf (SW Iberian Peninsula), in order to: 1) understand the succession of sedimentary processes during each shelf flooding episode and 2) explore the significance of variable rates of sea-level rise, sediment fluxes, and climatic conditions on the development of postglacial deposits. Four backstepping seismic postglacial transgressive units (PTUs; 4 to 1 from oldest to youngest) that are linked to the retreating mouth of the Guadiana River were interpreted. Together, these seismic units display a wedge-shape geometry, are located over the inner to middle shelf, and overlie a regional unconformity formed during the Last Glacial Maximum. Each PTU can be divided into several sub-units with distinctive seismic facies that have a similar stratigraphic organization. Each PTU contains lower sub-units that are composed of low-angle tangential-oblique clinoforms. The clinoforms are locally topped by a channelized sub-unit. The distal and/or lateral parts of the clinoforms are occasionally buried by sheet-like semitransparent subunits. The uppermost sub-units are present over the proximal and central parts of each seismic unit and are also sheet-like. PTUs can also be subdivided and described sedimentologically. Fine-grained sands with intercalated silty layers dominate the lower part of each PTU (lower clinoform sub-units). The upper part of each PTU (upper sheet-like sub-units) is characterized by reworked facies, composed of highly fragmented bioclasts within a mixture of silt and coarse to medium sand. Finally, mud deposits occur as a sediment drape over the PTUs. The internal structure of each PTU reveals several phases of development under a general process of transgressive submergence in which both coastal and marine deposits were formed and eventually preserved. The initial phase involved the development of coarse-grained deltas in shallow water, which were locally eroded by a network of distributary channels. In a transitional phase, the infilling of distributary channels and the offshore export of fine-grained sediments is related to a change in sediment sources, possibly triggered by enhanced hydrodynamic processes. The final phase involved the reworking of fluvio-deltaic sediments by shoreface processes to generate a sediment sheet. Age correlation with a suite of postglacial sea-level curves indicates that the formation of the postglacial transgressive deposits is bracketed between 14 ka and 9 ka. The studied deposits are related to a period of reduced sea-level rise, culminating in the Younger Dryas event (two oldest PTUs), and to phases of enhanced sea-level rise, such as Meltwater Pulse (MWP) 1B (two youngest PTUs). In spite of high rates of sea-level rise over MWP-1B, each PTU exhibits progradation and preservation of much of the delta. The preservation of progradational deltaic units is likely caused by increased sediment supply during progradational pulses. We suggest that those pulses of enhanced sediment fluxes during MWP-1B were strongly driven by the overall climatic conditions in the southwest of the Iberian Peninsula, probably resulting from enhanced rainfall runoff during humid periods and scarce land vegetation cover. Versión final del artículo en la web de la editorial

Puga Bernabeu, Ángel Braga Alarcón, Juan Carlos Aguirre Rodríguez, Julio Martín Martín, José Manuel https://hdl.handle.net/10481/93415 2024-07-23T11:43:36Z

Sedimentary dynamics and topographic controls on the tidal-dominated Zagra Strait, Early Tortonian, Betic Cordillera, Spain Puga Bernabeu, Ángel; Braga Alarcón, Juan Carlos; Aguirre Rodríguez, Julio; Martín Martín, José Manuel The approximately 350 m-thick stratigraphic succession of the Zagra Strait records an important oceanographic phase of basin interconnection between the Atlantic Ocean (Guadalquivir Basin) and the Mediterranean Sea through the Betic Cordillera (southern Spain) during the early Tortonian. The Zagra Strait developed as a narrow structurally controlled marine corridor. The sedimentary dynamics of the Zagra Strait were interpreted from the sedimentological features observed in six sections at well-exposed outcrops. Large-scale (>10 m high) compound dunes and compound–dune complexes moved parallel to the strait margins under strong tidal currents generated by tidal amplification at the strait entrance and exit. Dune distribution can be divided into three sectors with different palaeocurrent migration, lithological and topographical characteristics. The northern and central sectors were separated by a deep depression (>75 m water depth) where tidal currents were weaker and dunes were not generated. The southern sector records a relative decrease in current strength compared with the northern and central sectors, and a significant increase in the bioclastic content in the sediment. Terrigenous content generally increases towards the strait margins, and reciprocally, carbonates towards its axis. The closure of the Zagra Strait resulted from tectonic uplift of that part of the Betic Cordillera before the late Tortonian.

Puga Bernabeu, Ángel Martín Martín, José Manuel Braga Alarcón, Juan Carlos Aguirre Rodríguez, Julio Pérez Asensio, José Noel Reolid Pérez, Jesús https://hdl.handle.net/10481/92209 2024-06-03T06:55:59Z

Integración virtual de datos multiescala en las prácticas de campo en Geología Puga Bernabeu, Ángel; Martín Martín, José Manuel; Braga Alarcón, Juan Carlos; Aguirre Rodríguez, Julio; Pérez Asensio, José Noel; Reolid Pérez, Jesús La didáctica de la Geología presenta al alumnado una gran cantidad de conceptos y terminología especifica, cuya comprensión y asimilación se realiza de forma más efectiva durante las prácticas de campo. Estas actividades son fundamentales, pero consumen grandes recursos económicos y de dedicación docente por parte del profesorado. Sin embargo, los crecientes recursos tecnológicos en el ámbito didáctico, como la virtualización de contenidos, ofrecen una valiosa herramienta de trabajo para complementar la formación de las prácticas de campo, ya que permiten tanto la repetición de experiencias de las prácticas como la adquisición de nuevos conocimientos. En este proyecto se plantea la continuación de la línea docente de virtualización de las prácticas de campo en Geología mediante la creación de ejemplos virtuales de afloramiento que incluyan datos de observación a multiescala. Este recurso complementará el repertorio de herramientas virtuales ya existentes en el Departamento de Estratigrafía y Paleontología de la Universidad de Granada. Con ello, se pretende reforzar el aprovechamiento de los recursos virtuales en los ámbitos de la sedimentología y la geología sedimentaria. El objetivo principal del proyecto es desarrollar modelos virtuales de afloramientos que integren datos geológicos, sedimentológicos, estratigráficos y paleontológicos obtenidos a diferente escala de observación, desde (1) macroescala, que permiten la división de unidades estratigráficas y la definición de su morfología, a (2) mesoescala en la que se caracteriza la litología, estructuras sedimentarias y contenido fósil, y (3) microescala, que permite la caracterización de las microfacies y rasgos diagenéticos. Con estos modelos se busca fomentar y facilitar el aprendizaje del alumnado sobre el estudio integrado de un afloramiento, abarcando desde las relaciones estratigráficas entre unidades hasta el análisis de las microfacies. De forma específica, se plantea: - Consolidar los conocimientos teóricos y prácticos adquiridos en clases, prácticas de laboratorio y salidas de campo de geología. - Dotar a los estudiantes de una herramienta de consulta rápida que les permita repasar contenidos, fomentando así su autonomía. - Involucrar a los estudiantes en el estudio de la sedimentología y la geología sedimentaria, motivándolos a aplicar sus conocimientos en otras salidas de campo y en su vida profesional. Para la consecución de los objetivos establecidos, se comprobó, en primer lugar, la disponibilidad de modelos fotogramétricos (modelos virtuales) de afloramiento creados por el equipo de innovación docente en el seno del Grupo de Investigación RNM190 de la Junta de Andalucía. Tras identificar los modelos más relevantes y que pudieran ser adaptados en términos de tamaño y resolución para su publicación en línea, se procedió al levantamiento de secciones estratigráficas en el área de los modelos fotogramétricos y a la recogida de muestras para la preparación de láminas delgadas. Posteriormente, se llevó a cabo la interpretación de los modelos fotogramétricos e integración de las secciones estratigráficas y análisis de microfacies. Finalmente, se realizó el montaje y edición de la herramienta virtual para su publicación en línea. El proyecto de innovación proporciona una herramienta de acceso libre de apoyo a la docencia práctica de la Geología al estudiantado y profesorado de la Universidad de Granada. El contenido virtual generado facilita la comprensión y razonamiento de los conceptos teóricos explicados en clase, al mismo tiempo que contribuye al desarrollo de actitudes y competencias fundamentales de los estudiantes, como la capacidad para aplicar conocimientos a la práctica, el pensamiento reflexivo y mejorar sus capacidades de acceso y gestión de la información. De forma específica, el contenido de la herramienta virtual del proyecto reforzará las capacidades de los estudiantes para (1) identificar y caracterizar las propiedades de los diferentes materiales y procesos geológicos y (2) recoger, analizar, interpretar y representar datos referentes a materiales geológicos. Además, los modelos virtuales integrados facilitan también la adquisición del conocimiento de forma gradual y el “descubrimiento autónomo”, lo que permite a los estudiantes desarrollar sus propias ideas e interpretaciones que pueden contrastar con las descripciones y detalles proporcionados por el equipo de innovación en la herramienta virtual. Esta herramienta virtual está especialmente orientada al Grado en Geología, aunque puede ser útil en asignaturas con contenido geológico en los Grados de Biología, Ciencias Ambientales e Ingeniería Civil. Además, puede ser de utilidad para aquellos estudiantes que cursan algunas asignaturas de los diferentes Máster relacionados con la Geología. Varios de los modelos virtuales integrados del proyecto corresponden a afloramientos que visitan como parte de varias salidas de prácticas de campo en el Grado en Geología. Esto ayudará a los estudiantes a consolidar el flujo de trabajo realizado en el estudio de los afloramientos y permitirá al profesorado realizar un seguimiento y evaluación de los contenidos y competencias.; Geology teaching introduces students to a wide range of concepts and terminology, whose comprehension and assimilation are most effectively achieved during fieldwork. These activities, while essential, consume significant economic resources and require considerable dedication from the teaching staff. However, the increasing technological resources in educational settings, such as content virtualisation, offer a valuable tool to complement fieldwork training. They allow the repetition of field experience and tie the acquisition of new knowledge. This project aims to continue the educational line of fieldwork virtualisation in geology by creating virtual outcrop examples incorporating multiscale observational data. This teaching resource will complement the existing collection of virtual tools in the Department of Stratigraphy and Palaeontology of the University of Granada, aiming to enhance the use of virtual resources in sedimentology and sedimentary geology. The main objective of the project is to develop virtual outcrop models that integrate geological, sedimentological, stratigraphic, and palaeontological data obtained at different observation scales: (1) macroscale, enabling the division of stratigraphic units and the definition of their morphology; (2) mesoscale, characterising lithology, sedimentary structures and fossil content; and (3) microscale, allowing the characterisation of microfacies and diagenetic features. These models seek to promote and facilitate student learning about the integrated study of an outcrop, from stratigraphic relationships between units to microfacies analysis. Specifically, the project aims to: - Consolidate the theoretical and practical knowledge acquired in geology classes, laboratory practices and fieldwork. - Provide students with a quick reference tool that allows them to review the content, thus promoting their autonomy. - Engage students in the study of sedimentology and sedimentary geology, motivating them to apply their knowledge on other field trips and in their professional lives. To achieve the objectives set, the first step was to check the availability of outcrop photogrammetric models (virtual models) produced by the educational innovation team within the Research Group RNM190 of the Junta de Andalucía. After identifying the most relevant models that could be adapted in terms of size and resolution for online publication, stratigraphic sections were logged in the area of the photogrammetric models and samples were collected for thin section preparation. The photogrammetric models were then interpreted and the stratigraphic sections and microfacies analysis were integrated. Finally, the virtual tool was assembled and edited for online publication. This innovation project provides a freely accessible tool to support the practical teaching of geology to students and teachers at the University of Granada. The virtual content generated facilitates the understanding and reasoning of theoretical concepts explained in class, while also contributing to the development of fundamental competencies of students, such as the ability to apply knowledge in practice, reflective thinking, and the improvement of information access and management skills. Specifically, the content of the virtual tool will enhance students' abilities to (1) identify and characterise the properties of different geological materials and processes, and (2) collect, analyse, interpret and present data related to geological materials. In addition, the integrated virtual models also facilitate gradual knowledge acquisition and 'autonomous discovery', allowing students to develop their own ideas and interpretations that can be compared with the descriptions and details provided by the innovation team in the virtual tool. This virtual tool is specifically oriented to the Geology Degree, although it can be useful in courses with geological content in the Biology, Environmental Sciences, and Civil Engineering degrees. In addition, it may be useful for students enrolled in some subjects of Master’s programs related to Geology. Several of the integrated virtual models in the project correspond to outcrops visited as part of the fieldwork practises in the Geology Degree. This will help students consolidate the workflow used in the outcrop studies and enable lecturers to monitor and evaluate contents and skills in more detail.

Puga Bernabeu, Ángel https://hdl.handle.net/10481/73453 2022-03-15T17:09:41Z

Submarine landslide morphometrics and slope failure dynamics along a mixed carbonate-siliciclastic margin, north-eastern Australia Puga Bernabeu, Ángel Comparatively little work has been carried out on the morphology and distribution of submarine landslides onmixed carbonate-siliciclastic margins. The morphometric analysis of 84 open slope submarine landslides on the Great Barrier Reef (GBR) margin of north-eastern Australia provides useful insights into slope failure dynamics and frequency distribution of landslides on mixed margins. Our analysis has revealed that the slope area affected by failures (12.6% of the margin) is similar to siliciclastic-dominated passive margins, although the total volume of remobilized sediment (73 km3) is comparatively small. Landslide scars lie at shallower depths to the south of the margin (mean of 576 m vs 1517 m to the north) and there is good correlation between the depth at origin and depth at termination for the GBR landslides. The cumulative frequency distribution of volume, area and total length of the GBR landslides does not fit to common distributions (e.g., power law, logarithmic or exponential) for the entire dataset. Still, the cumulative frequency distribution of landslide dimensions can be statistically explained either by a power law similar to other passive margins, or by a lognormal distribution similar to some siliciclastic margins. Morphometric characteristics, such as the volume of sediment released per unit width and the probability function of volume distribution suggest that slope failures mainly involved relatively unconsolidated sediments. We find that the disintegration by debris flows was the dominant process along the entire GBR margin and that their spreading efficiency and mobility was relatively low. Margin stratigraphy, fluid overpressure at the base of the slope, and detachment surfaces at the boundary between different lithologies that separate sedimentary cycles may have preconditioned the slope to fail. This compilation provides a robust morphometric framework that allows comparison with existing and future slope failure databases, and lays the foundation for performing numerical simulations to assess the landslide-generated tsunamigenic hazards along the GBR margin.

García-Alix Daroca, Antonio Jiménez-Espejo, Francisco José Jiménez Moreno, Gonzalo Toney, Jaime, L Ramos-Román, María J. Camuera, Jon Delgado Huertas, Antonio Martínez Ruiz, Francisca Queralt, Ignasi https://hdl.handle.net/10481/49851 2021-06-22T08:22:55Z

Holocene geochemical footprint from Semiarid alpine wetlands in southern Spain García-Alix Daroca, Antonio; Jiménez-Espejo, Francisco José; Jiménez Moreno, Gonzalo; Toney, Jaime, L; Ramos-Román, María J.; Camuera, Jon; Delgado Huertas, Antonio; Martínez Ruiz, Francisca; Queralt, Ignasi Here we provide the geochemical dataset that our research group has collected after 10 years of investigation in the Sierra Nevada National Park in southern Spain. These data come from Holocene sedimentary records from four alpine sites (ranging from ∼2500 to ∼3000 masl): two peatlands and two shallow lakes. Different kinds of organic and inorganic analyses have been conducted. The organic matter in the bulk sediment was characterised using elemental measurements and isotope-ratio mass spectrometry (EA-IRMS). Leaf waxes in the sediment were investigated by means of chromatography with flame-ionization detection and mass spectrometry (GC-FID, GC-MS). Major, minor and trace elements of the sediments were analysed with atomic absorption (AAS), inductively coupled plasma mass spectrometry (ICP-MS), as well as X-ray scanning fluorescence. These data can be reused by environmental researchers and soil and land managers of the Sierra Nevada National Park and similar regions to identify the effect of natural climate change, overprinted by human impact, as well as to project new management policies in similar protected areas.