Unconformity-bounded stratigraphic units (UBSUs) in an italian alluvial-plain area: recognizing and dating

We studied the coastal zone of the Tavoliere di Puglia plain, (Puglia region, southern Italy) with the aim to recognize the main unconformities, and therefore, the unconformity-bounded stratigraphic units (UBSUs; Salvador 1987, 1994) forming its Quaternary sedimentary fill. Recognizing unconformities is particularly problematic in an alluvial plain, due to the difficulties in distinguishing the unconformities that bound the UBSUs. So far, the recognition of UBSUs in buried successions has been made mostly by using seismic profiles. Instead, in our case, the unavailability of the latter has prompted us to address the problem by developing a methodological protocol consisting of the following steps: I) geological survey in the field; II) draft of a preliminary geological setting based on the field-survey results; III) dating of 102 samples coming from a large number of boreholes and some outcropping sections by means of the amino acid racemization (AAR) method applied to ostracod shells and 14C dating, filtering of the ages and the selection of valid ages; IV) correction of the preliminary geological setting in the light of the numerical ages; definition of the final geological setting with UBSUs; identification of a ‘‘hypothetical’’ or ‘‘attributed time range’’ (HTR or ATR) for each UBSU, the former very wide and subject to a subsequent modification, the latter definitive; V) cross-checking between the numerical ages and/or other characteristics of the sedimentary bodies and/or the sea-level curves (with their effects on the sedimentary processes) in order to restrict also the hypothetical time ranges in the attributed time ranges. The successful application of AAR geochronology to ostracod shells relies on the fact that the ability of ostracods to colonize almost all environments constitutes a tool for correlation, and also allow the inclusion in the same unit of coeval sediments that differ lithologically and paleoenvironmentally. The treatment of the numerical ages obtained using the AAR method required special attention. The first filtering step was made by the laboratory (rejection criteria a and b). Then, the second filtering step was made by testing in the field the remaining ages. Among these, in fact, we never compared an age with a single preceding and/or following age; instead, we identified homogeneous groups of numerical ages consistent with their reciprocal stratigraphic position. This operation led to the rejection of further numerical ages that deviate erratically from a larger, homogeneous age population which fits well with its stratigraphic position (rejection criterion c). After all of the filtering steps, the valid ages that remained were used for the subdivision of the sedimentary sequences into UBSUs together with the lithological and paleoenvironmental criteria. The numerical ages allowed us, in the first instance, to recognize all of the age gaps between two consecutive samples. Next, we identified the level, in the sedimentary thickness that is between these two samples, that may represent the most suitable UBSU boundary based on its lithology and/or the paleoenvironment. The recognized units are: I) Coppa Nevigata sands (NEA), HTR: MIS 20–14, ATR: MIS 17–16; II) Argille subappennine (ASP), HTR: MIS 15–11, ATR: MIS 15–13; III) Coppa Nevigata synthem (NVI), HTR: MIS 13–8, ATR: MIS 12–11; IV) Sabbie di Torre Quarto (STQ), HTR: MIS 13–9.1, ATR: MIS 11; V) Amendola subsynthem (MLM1), HTR: MIS 12–10, ATR: MIS 11; VI) Undifferentiated continental unit (UCI), HTR: MIS 11–6.2, ATR: MIS 9.3–7.1; VII) Foggia synthem (TGF), ATR: MIS 6; VIII) Masseria Finamondo synthem (TPF), ATR: Upper Pleistocene; IX) Carapelle and Cervaro streams synthem (RPL), subdivided into: IXa) Incoronata subsynthem (RPL1), HTR: MIS 6–3; ATR: MIS 5–3; IXb) Marane La Pidocchiosa–Castello subsynthem (RPL3), ATR: Holocene; X) Masseria Inacquata synthem (NAQ), ATR: Holocene. The possibility of recognizing and dating Quaternary units in an alluvial plain to the scale of a marine isotope stage constitutes a clear step forward compared with similar studies regarding other alluvial-plain areas, where Quaternary units were dated almost exclusively using their stratigraphic position. As a result, they were generically associated with a geological sub-epoch. Instead, our method allowed a higher detail in the timing of the sedimentary processes: for example, MIS 11 and MIS 5.5 deposits have been recognized and characterized for the first time in the study area, highlighting their importance as phases of sedimentation.

Structure of Alluvial Valleys from 3-D Gravity Inversion: The Low Andarax Valley (Almería, Spain) Test Case

This paper presents a gravimetric study (based on 382 gravimetric stations in an area about 32 km2) of a nearly flat basin: the Low Andarax valley. This alluvial basin, close to its river mouth, is located in the extreme south of the province of Almería and coincides with one of the existing depressions in the Betic Cordillera. The paper presents new methodological work to adapt a published inversion approach (GROWTH method) to the case of an alluvial valley (sedimentary stratification, with density increase downward). The adjusted 3D density model reveals several features in the topography of the discontinuity layers between the calcareous basement (2,700 kg/m3) and two sedimentary layers (2,400 and 2,250 kg/m3). We interpret several low density alignments as corresponding to SE faults striking about N140?145°E. Some detected basement elevations (such as the one, previously known by boreholes, in Viator village) are apparently connected with the fault pattern. The outcomes of this work are: (1) new gravimetric data, (2) new methodological options, and (3) the resulting structural conclusions.

España: evolutionism & religion, Century XIX

From the Englightenment to the middle of the 19th century, geological time and the antiquity of human beings received ever growing attention. This was caused by a series of events, such as: *the beginnings of experimentation in Geology (Buffon, 1778) *the development of the transformism (Lamarck, 1809) *the recognition and description of extinct animals (Cuvier, 1812) *as well as the studies made in alluvial deposits, caves and gravel beds, with brought to light artefacts, human rest and bone of extinguished animals (from John Frere, 1797, to Albert Gaudry, 1859). The development towards evolutionism (Darwin, 1859) came gradually. In Spain, all these currents found their echo: Spain, e.g. was the third country where the Palaeolithic remains were discovered (Verneuil and Lartet, 1863). Also the Darwin ideas were introduced forcefully, right from the beginning. But the change in worldview, which was prerequisite to these ideas, lead to polemic controversies in the political and religious realm. The most significant evidence was the official prohibition of the teaching Darwinism in public educational centres (1875). At theological level, thanks to the advance of the geologic knowledge, went leaving the literal interpretations of Biblical texts was eventually discontinued and replaced by more liberal interpretation. In some case, the process was difficult because some political, religious and scientific authors and researchers didn’t understand the new scientific ideas.

La geoquímica de los sedimentos de llanuras de inundación como guía para la valoración ambiental en España

En la presente tesis se estudian los contenidos geoquímicos de los sedimentos de llanura de inundación en diversas cuencas fluviales seleccionadas con el objetivo de contribuir a un mejor conocimiento de sus condiciones medioambientales. En cada cuenca, se ha muestreado un perfil vertical de llanura de inundación, dividiéndolo en tramos que generalmente corresponden a diferentes episodios de inundación. Estos sedimentos se depositan durante los episodios de crecidas una vez que la corriente sobrepasa los límites del canal. Se caracterizan normalmente por tener un tamaño de grano fino y una estructura en capas horizontales que corresponden a los sucesivos episodios de inundación. Muestran dos ventajas principales con respecto a otros medios de muestreo en geoquímica como suelos o sedimentos de corriente: • Pueden almacenar sedimento antiguo así como actual, con lo que se puede estudiar la historia geoquímica de una zona específica en un mismo punto de muestreo (perfil vertical). • Los sedimentos de llanuras de inundación son capaces de caracterizar grandes áreas de drenaje. El origen de los sedimentos es más diverso que en el sedimento de corriente, debido a las mayores áreas de donde proceden las aguas de las avenidas. Las cuencas han sido seleccionadas según las actividades antropogénicas que en ellas se llevan a cabo, en concreto, actividades urbanas e industriales, minería y agricultura. Así mismo, se han estudiado, como referencia, dos cuencas donde no se espera encontrar ningún tipo de actividad contaminante. Una vez hecha la selección, los sedimentos aluviales de las cuencas se han estudiado cuidadosamente para asegurar que no existen depósitos de acreción lateral en el punto seleccionado. Posteriormente se ha procedido al muestreo del perfil vertical. Las muestras han sido analizadas mediante ICP-MS (ataque total) e INAA para conocer los contenidos totales de los elementos traza y mayoritarios. Los análisis de la fracción extraíble se han llevado a cabo mediante ICP-MS (ataque con agua regia). Así mismo, algunas muestras seleccionadas han sido sometidas a una extracción secuencial para un estudio más detallado. La presencia de materia orgánica ha sido estimada mediante el análisis de Carbono Orgánico Total (TOC). Finalmente, se ha llevado a cabo un análisis de isótopos de Pb en muestras escogidas en los perfiles, con el objetivo de hacer una evaluación ambiental. Los contenidos metálicos aumentan hacia la superficie en algunos de los perfiles, mientras en otros muestran una distribución muy constante exceptuando algún nivel específico con un aumento de los contenidos de la mayoría de los metales. Ha sido posible determinar la influencia de las actividades antropogénicas en algunos de los perfiles. Aquellos que pertenecen a cuencas mineras, urbanas o industrializadas muestran generalmente altos contenidos en elementos metálicos. Es el caso de los perfiles muestreados en los ríos Odiel y Tinto, Besaya, Besós y Manzanares. Algunos de estos perfiles pueden incluso correlacionarse con periodos de tiempo en los que ha tenido lugar una actividad antropogénica más intensa. Los perfiles que mejor se correlacionan con la actividad antropogénica de la cuenca son el perfil de Rivas en el río Manzanares (Madrid), que refleja un crecimiento de la contaminación producida por las actividades urbana e industrial en las últimas décadas, y el río Tinto, que muestra un crecimiento llamativo de los contenidos en su mayoría metálicos que puede estar relacionado con el incremento de la actividad minera que tuvo lugar hace aproximadamente 125 años. El análisis de los isótopos de Pb ha resultado ser una herramienta útil en la evaluación ambiental de estos sedimentos. Con este estudio y mediante la comparación con fuentes naturales y antropogénicas, ha sido posible diferenciar las muestras afectadas por diferentes fuentes de plomo, así como detectar las más afectadas antropogénicamente. ABSTRACT The geochemical composition of overbank sediments of some selected river basins is studied in this thesis in order to contribute to a better knowledge of the environmental conditions surrounding them. In each basin a vertical overbank profile has been sampled, dividing it into stretches that usually correspond to different flood events. The overbank sediments are those deposited during a flood event once the flow spills over the channel banks. They are usually characterized by a very fine grain size and a structure of horizontal layers, which correspond to successive flood events. These sediments show two main advantages regarding other sampling media in geochemistry, like soils or stream sediments: • They can store sediment deposited in the past as well as in current times, so that the history of a specific location can be studied at the very same point (vertical profile). • The overbank sediments are able to characterize a large drainage area. The origin of the sediment is wider than in the stream sediments due to the larger areas where the flood water comes from. The basins have been selected depending on the anthropogenic activities developed in them, namely, urban and industrial activities, mining activities and agricultural activities. As well, two pristine basins have been studied as a reference. Afterwards, the alluvial sediments in the basins have been carefully studied in order to sample a vertical profile and make sure that lateral accretion materials are not present in the profile. The samples have been analysed by ICP-MS (total digestion) and INAA to know the total contents of trace and major elements. Analysis of the mobile fraction has been carried out by ICP-MS (aqua regia); as well some of the samples have been subjected to sequential extraction for a more detailed study. The presence of organic matter has been estimated by the analysis of the Total Organic Carbon (TOC). Finally, a lead isotope analysis of some of the samples in the profiles was carried out in order to make an environmental assessment. Metal contents grow towards the surface in some of the profiles, while others show a very steady distribution, except for some of them with a growth of most of the metals in a specific level. XI It has been possible to determine the influence of the anthropogenic activities in some of the profiles. The ones that belong to mining and urban or industrialized basins show generally high contents of metal elements. This is the case of the profiles sampled in the Odiel and Tinto Rivers, the Besaya River, the Besós River and the Manzanares River. Some of these profiles can even correlate with the periods of time when a more intense activity in their respective basins has taken place. The profiles which best correlate with the anthropogenic activity are the Rivas profile in the Manzanares River, which reflects a growth of the pollution produced by urban and industrial activities in the city of Madrid in the last decades and the Tinto profile, which shows a very dramatic growth of the elemental contents (mostly metals) which can be related to the increase of the mining activities that took place in the last 125 years. The analysis of lead isotopes has turned out to be a powerful tool in the environmental assessment in this type of sediments. With this study and through the comparison with natural and anthropogenic sources, it has been possible to determine samples affected by different sources of lead and to detect the most anthropogenicaly affected ones.

Análisis de la técnica de recarga artificial en la Cubeta de Sant Andreu de la Barca (Barcelona)

El presente proyecto pretende mostrar las posibilidades de la recarga artificial como elemento de gestión de los recursos de agua subterránea del acuífero aluvial del río Llobregat, en su sector de la Cubeta de Sant Andreu de la Barca (Barcelona), el cual es fuente de abastecimiento urbano, agrícola e industrial del entorno de Sant Andreu de la Barca. Igualmente, se revisa la efectividad de la aplicación de dicha técnica que se practica actualmente. Hace años, las condiciones naturales del río hacían posible la recarga natural de la Cubeta, pero la implantación de industrias en la zona y la regulación mediante la presa de La Baells desde el año 1976, han originado cambios en el comportamiento natural del acuífero, que se han manifestado básicamente en una disminución de la recarga natural como consecuencia de la impermeabilización de los suelos originada por la urbanización de los mismos. Se ha producido también un fenómeno de colmatación del lecho del río, al dificultarse la removilización de los materiales finos depositados en el fondo del cauce, produciendo también una disminución de la recarga al acuífero a través del lecho. Por último, la mayor demanda de suministro por parte del sector industrial ha influido negativamente en el almacenamiento del acuífero. Desde hace décadas, se lleva efectuando una recarga artificial en el lecho del río para tratar de paliar en lo posible estos efectos perjudiciales. La misma se efectúa mediante dos sistemas distintos: escarificando el lecho del río para aumentar su capacidad de infiltración, y mediante la utilización de balsas de recarga, a través de las cuales se infiltra el agua en el acuífero. El objetivo de este proyecto es analizar el efecto actual que la recarga mediante balsas está teniendo sobre el acuífero. Para ello, se utilizarán, entre otras técnicas, la elaboración de un modelo matemático con el que poder simular el efecto de la recarga. VIII ABSTRACT This project aims to show the possibilities of artificial recharge as groundwater resources management element in the alluvial aquifer of the Llobregat River, in the sector of the Basin of Sant Andreu de la Barca (Barcelona), which is a source of urban, agricultural and industrial supply of the Sant Andreu de la Barca area. Too, the effectiveness of the current implementation of this technique is reviewed. Years ago, natural river conditions made possible the natural recharge of the aquifer, but the establishment of industries in the area and the river regulation by the la Baells dam since 1976, have led to changes in the natural behavior of the aquifer, which basically are a decrease in natural recharge, because the soil has become impervious, due to land urbanization. There has been also a phenomenon of clogging of the river bed, caused by the difficult in the remobilization of fine materials deposited on the river bed, which has produced a decrease in the groundwater recharge through the river. Finally, the increase in water demand by the industrial sector, has diminished aquifer storage. For decades, artificial recharge in the river bed has been practiced to alleviate negative effects. It is done by two different systems: scratching the river bed to increase its infiltration capacity, and using recharge ponds, through which water infiltrates into the aquifer. The objective of this project is to analyze the current effect that recharge by ponds is having in the aquifer. Among other techniques, mathematical modeling has been used for simulating the effect of artificial recharge in the aquifer.

Mapa preliminar de períodos predominantes del suelo en Puerto Príncipe (Haití) a partir de medidas de ruido ambiental.

The 2010 Haiti earthquake, occurred on January 12th at 16:53:09 local time (21:53:09 UTC) with epicentral distance of 15 km from the capital Port au Prince, MW 7.0 and 13 km hypocenter deep, was the strongest event in the area since happened in 1770. The maximum macroseismic intensity was estimated as X (MMI scale). The aim of this research is to obtain a preliminary zonation of Port-au-Prince in terms of predominant resonance periods of ground. A total of 36 short-period ambient noise records have been carried out on a grid of about 500x500m. H/V spectral ratio method (HVSR) has been applied to determine the predominant period at each point. The lowest values (<0.2s) predominate in the southern part of the city, composed by Miocene conglomerates, while highest values (> 0.45s) correspond to the center and western parts, composed of Pleistocene-Holocene alluvial deposits and anthropogenic land reclaimed from the sea. We have determined the ground VS30 structure inside National Palace garden, using simultaneous ambient noise measurements. An array made up of 6 sensors were used, with 5 of them uniformly distributed along a circumference and a sixth one placed in its centre. The records were analyzed by using the spatial autocorrelation method (SPAC). The VS 30 value obtained was 331m/sec, in good agreement with the average values obtained for this area by other authors, using prospecting techniques.

Horizontal to vertical spectral ratio measurements in Port-au-Prince (Haiti) area damaged by the 2010 Haiti earthquake

In order to evaluate ground shaking characteristics due to surface soil layers in the urban area of Port-au-Prince, short-period ambient noise observation has been performed approximately in a 500x500m grid. The HVSR method was applied to this set of 36 ambient noise measurement points to determine a distribution map of soil predominant periods. This map reveals a general increasing trend in the period values, from the Miocene conglomerates in the northern and southern parts of the town to the central and western zones formed of Pleistocene and Holocene alluvial deposits respectively, where the shallow geological materials that cover the basement increase in thickness. Shorter predominant periods (less than 0.3 s) were found in mountainous and neighbouring zones, where the thickness of sediments is smaller whereas longer periods (greater than 0.5 s) appear in Holocene alluvial fans, where the thickness of sediments is larger. The shallow shear-wave velocity structure have been estimated by means of inversion of Rayleigh wave dispersion data obtained from vertical-component array records of ambient noise. The measurements were carried out at one open space located in Holocene alluvial deposits, using 3 regular pentagonal arrays with 5, 10 and 20m respectively. Reliable dispersion curves were retrieved for frequencies between 4.0 and 14 Hz, with phase velocity values ranging from 420m/s down to 270 m/s. Finally, the average shear-wave velocity of the upper 30 m (VS30) was inverted for characterization of this geological unit.

Cálculo de la recarga natural en grandes áreas, en función de la litología y la precipitación = Calculation of natural recharge in large areas, as a function of lithology and rainfall

En una región amplia como España se demuestra —mediante inferencias estadísticas sobre una muestra completa de 875 manantiales en los que se conoce su caudal medio y la litología de su área de alimentación y que han sido agrupados en regiones de distinta pluviometría— que la recarga media anual es una fracción fija de la precipitación media para cada litología. Se han establecido así unas tasas de recarga respecto de la precipitación para seis grupos litológicos de diferente permeabilidad: arenas, gravas y formaciones aluviales en general, 8.3%; conglomerados, 5.6%; areniscas, 7.3%; calizas y dolomías, 34.3%; margas, margocalizas, limos y arcillas, 3.3%; otras rocas, 1.3%. Teniendo en cuenta la representatividad de España, la cual tiene una gran variabilidad de litología, pluviometría, topografía, etcétera, estas tasas de recarga respecto de la precipita-ción son probablemente valores cuasi universales que pueden ser utilizados para estimar la recarga media o los recursos hídricos subterráneos medios de regiones amplias en cualquier parte del mundo, salvo en regiones especiales, como las que tienen permafrost, por ejemplo. En todo caso, estas tasas de recarga podrían ser retocadas para cada región según sus particulares características. Los datos de precipitación y litología son muy corrientes, por lo que el método puede ser ampliamente utilizado para completar balances hidráulicos.In a region as large as Spain, annual mean recharge is shown to be a fixed proportion of the mean rainfall for each lithology. This determination is based on statistical inferences from a complete sample of 875 springs for which mean flow and catchment areas are known and which have been grouped into distinct rainfall regions. Recharge rates have thus been established with respect to rainfall for six lithological groups with different permeability: sands, gravels and generally alluvial formations, 8.3%; conglomerates, 5.6%; sandstones, 7.3%; limestone and dolomite 34.3%; marls, marly limestones, silts and clays, 3.3%; and hard rocks, 1.3%. Considering the representativeness of Spain, which is large in size and has a highly varied lithology, topography and rainfall, these recharge rates for rainfall are probably quasi-universal values that can be used to estimate average recharge or average groundwater resources of large regions in any part of the world (except in special cases such as areas with permafrost, for example). For any case, these recharge rates can be adapted to each region according to its particular characteristics. Rainfall and lithology data are very common, and so the method can be widely used to calculate hydraulic balances.

Geomorphological analysis and evolution of an altered floodplain drainage system. The case of the Partido Stream (Spain)

The Partido Stream is a small torrential course that flows into the marsh of the Doñana National Park, an area that was declared a World Heritage Site in 1994. Before 1981, floods occurred, and the stream overflowed onto a floodplain. As an old alluvial fan, the floodplain has its singular orography and functionality. Fromthe floodplain, several drainage channels, locally called caño, discharged into themarsh. The Partido Streamhad themorphology of a caño and covered approximately 8 km from the old fan to the marsh. The stream was straightened and channelised in 1981 to cultivate the old fan. This resulted in floods that were concentrated between the banks in the following years, which caused the depth of water and the shear stress to increase, thus, scouring the river bed and river banks. In this case, the eroded materials were carried towards the marsh where a new alluvial fan evolved. Control measures on the old fan were implemented in 2006 to stop the development of the new alluvial fan downstream over the marsh. Thus, the stream would partially recover its original behaviour that it had before channelisation, moving forwards in a new, balanced state. The present study describes the geomorphological evolution that channelisation has caused since 1981 and the later slow process of recovery of the original hydraulic-sedimentation regime since 2006. Additionally, it deepens the understanding of the original hydraulic behaviour of the stream, combining field data and 2D simulations.

Alteración del comportamiento hidráulico natural de la vertiente noreste de la marisma de El Rocío por efectos antrópicos

El geo-dinamismo torrencial es resultado de la incidencia de precipitaciones torrenciales en la cuenca hidrográfica, y se manifiesta por una intensificación del ciclo del agua (con la presencia de mayores volúmenes de escorrentía y la consiguiente aparición de repentinos y elevados caudales de avenida) e intensificación del ciclo de los sedimentos (mayor erosión del suelo, incremento del transporte de sedimentos en los cauces de drenaje y la formación de grades depósitos de sedimentos en el área dominada de la cuenca). Estos procesos naturales se pueden agravar si se realizan en la cuenca actuaciones que alteren sustancialmente su morfología; es el caso del arroyo del Partido, tributario a la marisma de El Rocío en el Parque Nacional de Doñana, cuyo encauzamiento del tramo final sobre su antiguo cono de sedimentación fue el causante de la formación de un nuevo cono de sedimentación sobre la marisma. Pero las intervenciones antrópicas también pueden dirigir el sistema hacia la estabilidad sedimentaria y el tramo final del arroyo del Partido ha experimentado asimismo actuaciones de carácter restaurador. El antiguo cono de sedimentación del arroyo del Partido es un lugar complejo en el que drenan también otros tres cursos que intercambian sus flujos con dicho arroyo durante las avenidas. Esta Memoria analiza cuatro situaciones del paraje objeto de estudio: la primera responde al estado original del lugar en cuestión (situación A); la segunda a la creada tras el encauzamiento del arroyo del Partido en 1981 (situación B); la tercera a la formada pasado un tiempo desde el encauzamiento, cuando el geo-dinamismo del lugar hizo sus efectos sobre el paraje en cuestión (situación C); y la cuarta la generada tras la restauración en el verano de 2006 del régimen hidráulico-sedimentario del arroyo del Partido con la Actuación núm. 3 del Proyecto Doñana 2005. Se han investigado los efectos que la alteración de la morfología del sistema de drenaje del antiguo cono de sedimentación del arroyo del Partido causa en los parámetros hidráulicos que desencadenan el geo-dinamismo torrencial. Para ello se han reproducido las condiciones morfológicas de las cuatro situaciones más representativas ya comentadas que ha experimentado el paraje en los últimos 30 años y que han condicionado el comportamiento de las avenidas torrenciales ocurridas en dicho periodo. En este contexto se ha elaborado un modelo hidrológico con el programa HECHMS a partir de la información disponible y un modelo hidrodinámico en 2D con el programa IBER; con este último se han comparado ocho escenarios característicos derivados de la incidencia de dos avenidas representativas de los eventos torrenciales de la zona sobre las morfologías contempladas. También se ha estudiado la tensión de arrastre de las avenidas dada su incidencia en el terreno sobre el que transitan, analizando de manera separada los efectos en los cuatro cauces de drenaje del antiguo cono de sedimentación y del resto de la superficie del mismo. La investigación realizada ha permitido describir minuciosamente el comportamiento de los drenajes locales del antiguo y complejo cono de sedimentación que bordea el noroeste de la marisma del Parque Nacional de Doñana, desde la marisma de El Rocío hasta la marisma gallega, lo que redundará en beneficio de la gestión del Parque Nacional de Doñana y de su entorno, y especialmente en la seguridad del perímetro oriental de la aldea de El Rocío. ABSTRACT The torrential geo-dynamism results from the effect of torrential precipitations on the hydrological watershed, and it shows ups with the intensification of the water cycle (with presence of higher volumes of run-off and the consequent appearance of sudden and high food flows) and intensification of the sediment cycle (higher soil erosion, increase of sediment transport in the drainage courses and the formation of big sediment deposits in the area downstream the watershed). These natural processes can worsen if actions that change the morphology of the watershed are carried out. It is the case of the Partido stream, tributary of the marsh of El Rocío in the Doñana National Park, whose channelization of the final stretch over its old alluvial fan was the cause of the formation of a new alluvial fan over the marsh. But human actions can also go toward the sediment stabilization, and the final stretch of the Partido stream has experienced restoration actions as well. The old alluvial fan of the Partido stream is a complex terrain where also other three courses exchange their flows during floods. This document analyses four situations of the area studied: the first corresponds to the original state of the place (situation A); the second is the state created after the channel of the Partido stream was built in 1981 (situation B); the third is the state formed after some time passed and the geo-dynamism caused effect in the channelization (situation C); and the forth situation is the one created after the restoration in summer of 2006 of the hydraulic-sedimentary regime of the Partido stream with de Action number 3 of the Doñana 2005 Project. It has been researched the effects that the alteration of the morphology of the drainage system of the old alluvial fan of the Partido stream causes to the hydraulic parameters that trigger the torrential geo-dynamism. For that, the morphologic conditions of the four more representative situations were reproduced. Those situations experienced in the area in the last 30 years have conditioned the behaviour of torrential floods in that period. In this context, a hydrologic model with HEC-HMS and a 2D hydro-dynamic model with IBER have been set up. With IBER, eight scenes have been compared resulting from the impact of two representative floods from torrential events in the region against the morphologies considered. Also, the shear stress of the floods on the terrain has been studied, analysing separately the effect in the four drainage courses of the old alluvial fan and in the rest of its surfaces. The research carried out has allowed describing in minute detail the behavior of the local drainages of the old and complex alluvial fan that border the northwest part of the marsh of Doñana National Park, from the marsh of El Rocío to the gallega marsh. This will result in benefit for the management of Doñana National Park and its surroundings, and especially for the safety of the eastern limit of El Rocío village.

Linking land cover changes in the subalpine and montane belts to changes in a torrential river.

Channel cbanges are the consequence of cbanges in sediment yield from the slopes and in the connectivity between slopes and channels bccause of distinct land use and climate inJpacts. In Ibis study, we investigated the characteristics and evolution of a short reach in the headwater of the !juez River, central-soutbem Pyrenees. Assessment of a series of sedimentar)' and geomorphic structures confirtned major cbanges to the valley boUom, mainly related to changes in the intensity of human activity. 'The oldest sedimentar)' structure is a terrace leve! located 3 10 4 m above the current alluvial plain. General deforestation, overgrazing and recwring tires in the montane belt ( 1100-1600 m a.sJ.) have led 10 increased soil erosioo and connectivity, and to tbe triggering of debris llows thal have been deposited on the fluvial tmace. Woody fragments from within the debris llows were dated using acceleraror mass spectrOmetry '"e radiocaroon tcchniques (AMS), yielding ages between 1 00 and 115 cal years BP, whicb coincides with tbe period of maximum deforestalion and human density in the Pyrenees. Depopulation and fannland abaodonment since tbe beginning of tbe 2001 oenrury has resulled in generalliJcod natural and artificial reforestation, a shrinkage of the eroded arcas aod a decline in connectivi¡y bdween slopes and the channel. 1be rnost impor1an1 consequence has been cbannel incision and oarrowing, and the development of a sedimed annour !ayer. Active sedimenl b8llSpOI1 is continui.Qg, although there has been a decrease in sed.iment yield from the slopes. Copyright O 2014 John Wiley & Soos, Ltd.

Study of the foundations, bearing soil and stability of the minaret-tower of Cordobas Mosque

This research in Cordoba's mosque tower main objective was to analyze and characterize the foundations and the underlying soil, calculating the stability of the monument as well as the settlement and deformations performed, using traditional calculation methods and also by finite elements, and to determine differences between both, as well as the stability factor of the Minaret Tower. The works done to study the soil, were drill bores and dynamic penetration tests, classification of samples by size, Atterberg limits, physical and chemical analysis, showing the typical geotechnical composition of the Guadalquivir valley: an alluvial material composed by sand, gravels and silt clays. To study the foundations, inclined bore samples were extracted with 10-65º, showing calcarenite stone ashlars and lime concrete alternating with stone and brick masonry.

The MIS 5 palaeoenvironmental record in the SE Mediterranean coast of the Iberian Peninsula (Río Antas, Almería, Spain)

Se realiza un estudio detallado del episodio cálido MIS 5 en la zona sureste de la Península Ibérica. Se realiza la reconstrucción paleoambiental a partir del estudio polínico y biomarcadores de un sondeo perforado en la costa de Almería. La cronología se estableció a partir del método de racemizaciónd e aminoácidos.Landwards of a MIS5 bar, a borehole core (SRA) was analyzed to establish the relationship between the lagoonal record and the raised beach deposits in the surroundings of the Antas river mouth and to reconstruct the Pleistocene palaeoenvironmental evolution 5 of the southern Mediterranean coast of the Iberian Peninsula. 63 samples were recovered for amino acid racemization dating, 86 samples for sedimentological and paleontological determination, 37 samples for pollen identification and 54 for biomarker analysis. AAR revealed that the borehole record contains MIS11, MIS6 and MIS5 deposits, the latter extensively represented. During the end of MIS6 and MIS5, a sand 10 barrier developed and created a shallow lagoon with alternating terrestrial inputs this process being common in other Mediterranean realms. Litho- and biofacies allowed the identification of distinct paleoenvironments through time, with the presence of a lagoonal environment alternating with alluvial fan progradation. Biomarkers indicated constant input from terrestrial plants, together with variable development of aquatic 15 macrophytes. The palynological content allowed the reconstruction of the paleoclimatological conditions during MIS6 and 5, with evidence of seven scenarios characterized by alternating arid and relatively humid conditions