https://hdl.handle.net/10259/9026 Fri, 08 May 2026 01:36:10 GMT 2026-05-08T01:36:10Z https://hdl.handle.net/10259/9031 Propuesta metodológica para la caracterización de la mineralogía magnética en estudios paloambientales: aplicación al yacimiento de Atapuerca Bógalo Román, Mª Felicidad; Heller, F.; Villalaín Santamaria, Juan José; Calvo Rathert, Manuel; Osete López, María Luisa; Pérez González, Alfredo A methodology is proposed, which gives information about the contents of ferrimagnetic and antiferromagnetic minerals with different domain structure in soils and sediments. Isothermal remanent magnetisation (lRM) acquired and measured both at room temperature and at low temperature (77K) provides data which define a set of new parameters: ARMlc provides information about the fraction of superparamagnetic ferrimagnetics in the studied samples; parameters G and g, respectively, inform about absolute and relative contents of goethite, and parameters B and b discern the fraction of goethite, in superparamagnetic state. The proposed methodology is applied to the study of cave sediments from the palaeo-anthropological site of Atapuerca. Wed, 01 Jan 2003 00:00:00 GMT https://hdl.handle.net/10259/9031 2003-01-01T00:00:00Z https://hdl.handle.net/10259/9030 Propiedades magnéticas de los sedimentos de tipo estuarino: el caso de las Rías Baixas Rey García, Daniel; López Rodríguez, N.; Rubio Armesto, Belén; Vilas Martín, Federico; Mohamed Falcón, Kais Jacob; Pazos Rodríguez, Óscar; Bógalo Román, Mª Felicidad Este trabajo establece la utilidad de la susceptibilidad magnética como indicador de la influencia marina y evolución diagenética en sedimentos costeros de las Rías Baixas. Para ello se investigó la variabilidad geográfica de la susceptibilidad en 200 muestras de sedimentos marinos superficiales en las Rías de Vigo y Pontevedra. Su variabilidad vertical se estudió en 80 muestras de tres testigos de entre 60 y 90 cm de longitud extraídos en la Ría de Pontevedra. La susceptibilidad de las muestras superficiales aumenta progresivamente hacia mar abierto, y a medida que nos alejamos de las zonas de mayor influencia continental, estando relacionada con la textura y composición del sedimento, y por tanto, con su procedencia. Los testigos, más homogéneos litológicamente, mostraron una disminución muy importante de la susceptibilidad con la profundidad, estando ésta asociada a la evolución diagenética del sedimento. Para estudiar mejor estos procesos, se determinó la composición elemental y mineralógica, y además se midieron otras propiedades magnéticas de muestras representativas. Estos resultados se analizaron conjuntamente con los datos sedimentológicos disponibles, lo que permitió establecer que la variabilidad de la susceptibilidad dependía de tres factores principales: (a) procedencia y origen de los sedimentos, (b) régimen hidrodinámico de la zona y (c) presencia de partículas contaminantes discretas de origen antropogénico. También puede concluirse que la evolución de las fases magnetomineralógicas durante la diagénesis temprana está controlada por el contenido en materia orgánica, lo que a su vez determina el potencial de oxidación-reducción.; Meassurement of magnetic susceptibility has allowed the assesment of the marine influence and diagenetic evolution of coastal sediments from the Rías Baixas. This is based on geographically and vertically distributed data. The lowfield susceptibility (χ) of over 200 samples of surficial seabed sediments of the Rias of Vigo and Pontevedra showed a significant increase towards the open sea and away from continental influenced areas. Vertical variability of the susceptibility was evaluated in 80 samples obtained from three 60 to 90 cm long gravity corers in the Ria de Pontevedra. These samples showed a very strong decrease in susceptibility with depth. The surficial susceptibility values correlated well with the textural characteristics of the sediments, suggesting a link between sediment provenance and origin of the magnetic signal. To further evaluate these relationships, the available sedimentological data were completed with a number of elemental and mineralogical analysis. In addition some basic magnetic parameters were obtained for selected specimens. The combined analysis of these data showed that the spatial variability of the susceptibility observed in the different granulometric fractions can be spatially related to: (a) sediment provenance and origin, (b) hydrodynamic regime established between the Rias and the adjacent shelf, (c) antropogenic solid particulate pollution. It can also be concluded that the evolution of the magnetomineralogical phases during the early stages of burial and diagenesis is controlled by the organic matter content which in turn controls the redox potential. Sat, 01 Jan 2000 00:00:00 GMT https://hdl.handle.net/10259/9030 2000-01-01T00:00:00Z https://hdl.handle.net/10259/9029 Estudio de las propiedades magnéticas en las terrazas del río Tajo: implicaciones paleoambientales Bógalo Román, Mª Felicidad; Keller, P.; Pérez González, Alfredo; Gallardo, J.; Osete López, María Luisa Soil profiles from 12 terraces of Plio-Pleistocene to Holocene age from the Tajo river in Central Spain were investigated on there rock magnetic properties. Systematic profiles were sampled in O. 1 m intervals from 24 fresh trenches of 2.5m depth. The soil profiles consist of an upper eluvial horizon (A, E), a intermediate illuvial horizon (B), and sometimes a lower horizon (C). Low and high frequency susceptibility (x), saturation IRM (SIRM), and anhysteretic remanent magnetization (ARM) measurements were performed out. The differences between the stable values of horizon B and the high values of the horizons A and E increase with the age of the soils. Comparison of the mean values of the B horizons for each terrace show low X values for the Holocene and the Late Pleistocene, a strong x increase during the Middle Pleistocene, and again low values for the Pliocene and Early Pleistocene. Magnetic parameters of soils show the palaeoenvironmental changes during this period of time. Mon, 01 Jan 1996 00:00:00 GMT https://hdl.handle.net/10259/9029 1996-01-01T00:00:00Z https://hdl.handle.net/10259/9027 Estudio paleomagnético del volcanismo de Campos de Calatrava Bógalo Román, Mª Felicidad; Osete López, María Luisa; Ancochea Soto, Eumenio; Villalaín Santamaria, Juan José A first systematic paleomagnetic study has been carried out in the upper Miocene-Pliocene volcanism of the Campos de Calatrava region. 18 localities have been sampled and 14 of them yielded useful paleomagnetic results. A Pliocene paleomagnetic pole has been obtained for the Iberian Plate (Lat.=82.1ºN, Long.= 171.6ºE, A95=6.9). On the basis of the magnetic polarity results a zoning of the volcanism may be recognized which could be explained by a NE-ward migration of the volcanism in this region. Fri, 01 Jan 1993 00:00:00 GMT https://hdl.handle.net/10259/9027 1993-01-01T00:00:00Z