Alfonso Sopeña

Instituto de Geociencias

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Yolanda Sánchez Moya

Universidad Complutense de Madrid

Gerardo Benito

Museo Nacional de Ciencias Naturales

Amparo Ramos

Universitat de València

M. Rico

Instituto Pirenaico de Ecología

Varyl R. Thorndycraft

Royal Holloway University of London

María José Machado

Hospital General Universitario Gregorio Marañón

Marta Pérez‐Arlucea

Universidade de Vigo

I. Gil-Peña

Instituto Geológico y Minero de España

Teresa Román‐Berdiel

Universidad de Zaragoza

Cristina García‐Lasanta

Western Washington University

Cooperative Institutions

Universidad Complutense de Madrid

Consejo Superior de Investigaciones Científicas

Instituto de Geociencias

Instituto Geológico y Minero de España

Universidad de Zaragoza

Museo Nacional de Ciencias Naturales

Universitat de Barcelona

Universitat de València

Universidade de Vigo

National Research Council

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Palaeoflood response to climate and landuse changes in a Mediterranean river (Castellón, NE Spain)

EGUGA (2014)

Gerardo Benito María José Machado M. Rico Yolanda Sánchez Moya Alfonso Sopeña

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Gravel Bars in Low‐Sinuosity Streams (Permian and Triassic, Central Spain)

Amparo Ramos Alfonso Sopeña

The Buntsandstein sequence of the central area of Spain ranges from a variety of fluvial facies, low in the succession, to tidal mudstones and carbonates in the youngest and most eastern areas. This paper is restricted to the conglomerates in the lowest part of the fluvial sequence. These were deposited in bar and channel systems dominated by gravelly, low-sinuosity braided streams. Their distribution reflects both the pre-existing topography and synsedimentary tectonic movements. Six main facies have been distinguished (in order of decreasing abundance): sheets of massive conglomerates, channel-fill conglomerates, coarse–medium sandstones, lateral accretion conglomerates. tabular cross-stratified conglomerates, fine-grained sediments. Sheets of gravels, formed as longitudinal bars, were by far the major feature of sediment accumulation. Units of lateral accretion, if not very frequent, are quite important as they probably represent modifications of bars during waning stage. Two big cycles may be seen in these conglomerates. They correspond to different physiographic models. The lower cycle was mainly formed by smaller channels and bars than was the upper cycle. The lower cycle is mainly formed by channel deposits, whilst in contrast, the upper cycle is mainly made up of longitudinal bars. The change in sedimentation may be due to tectonic movements that occurred in the basin during Buntsandstein deposition.

Sinuosity

Conglomerate

10.1002/9781444303773.ch24

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Citations (141)

Oblique strain partitioning and transpression on an inverted rift: The Castilian Branch of the Iberian Chain

Tectonophysics (2008)

Gerardo de Vicente Ramón Vegas Alfonso Muñoz Martín J.D. van Wees Antonio María Casas Sáinz

Strain partitioning

Transpression

Massif

Orogeny

10.1016/j.tecto.2008.11.003

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Citations (107)

Subsidence analysis, maturity modellingand hydrocarbon generationof the Alpine sedimentaty sequence in the MWofthe Iberian Ranges (Central Spain)

Alfredo Ramos Alfonso Sopeña Yolanda Sánchez Moya Alfonso Muñoz Martín

A partir de los datos geologicos disponibles, se ha realizado la modelizacion computerizada de la evolucion termica y de la generacion de hidrocarburos de la sucesion sedimentaria permico-terciaria en el NW de la Cordillera Iberica. El analisis de la subsidencia indica que existen cuatro estadios diferenciados en la evolucion Mesozoica de este area durante el ciclo de sedimentacion Alpino. Estas cuatro etapas corresponden al Permico superior, Triasico, Jurasico inferior y medio, y Jurasico superior-Cretacico medio. Las diferencias observadas en las curvas de subsidencia tectonica obtenidas, permiten diferenciar cuatro dominios de cxtension/elevaeion. Estos dominios de extension/elevacion se definen como bloques limitados por fallas donde se han registrado similares procesos extensionales y/o de elevacion en un mismo estadio tectonico. Los dominios de extension/elevacion muestran la propagacion areal de los procesos tectonicos a traves del tiempo. Durante los tresprimeros estadios evolutivos, se produce una extension gradual a partir de un dominio central hacia el noreste y posteriormente hacia en suroeste. En el estadio CretAcico latendencia de propagacion se invierte. El flujo de caloren la base de la sucesiony la historia termica del area, han sido reconstruidos empleando diferentes modelos de distribucion del flujo de calor. La maduracion termica de la materia organica ha sido evaluada tentativamente, adoptando diferentes flujos de calor. Los resultados obtenidos se corresponden con los datos hasta ahora conocidos del area.

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Palaeoflood record of the Tagus River (Central Spain) during the Late Pleistocene and Holocene

Quaternary Science Reviews (2003)

Gerardo Benito Alfonso Sopeña Yolanda Sánchez Moya María José Machado Alfredo Pérez‐González

10.1016/s0277-3791(03)00133-1

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Citations (222)

Eliminación de fosfatos en muestras palinológicas

Geotemas ( Madrid ) (2012)

Alfonso Sopeña Yolanda Sánchez Moya R. Pozuelo Francisco Coruña Xabier Arroyo

The observation of palynological material from siliceous sediments needs separation and isolation techniques, which include a preliminary chemical treatment to eliminate mineral phases. The final residue, obtained after several treatments, is composed by a mixture of organic, vegetal and animal materials. In some cases the presence of mineral phases such as crystalline phosphates formed during the chemical attack is also confirmed. The elimination of these compounds from the palynological materials is very important for an adequate observation, study and count under the optical microscope. The aim of this work is to study and describe the newly formed phosphates during chemical treatment and to formulate a valid method for its elimination without damage of the playnological material. Two samples (Keuper facies, Upper Triassic) have been selected due to their content in the previously described problematic phosphate phases. XRD, XRF and optical microscopy data show that the newly formed phosphate phases, after the acid attack with HF (40% dissolution), are crandallite-gorceixite. After several laboratory attempts, the elimination of the problematic phases has been made successfully treating the samples with a final dissolution of HCl at 33%. All the morphological characteristics of the palynological material have been preserved properly.

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Holocene alluvial records and geomorphic changes in the upper Guadalentin basin (SE-Spain)

Xavier Rodríguez Lloveras María José Machado Yolanda Sánchez Moya Alfonso Sopeña Gerardo Benito

Trabajo presentado en el Congreso Ex AQUA, celebrado en Padua (Italia), del 26 de septiembre al 1 de octubre de 2016

Alluvial fan

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Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers

Hydrology and earth system sciences (2011)

Gerardo Benito Blanca A. Botero Varyl R. Thorndycraft M. Rico Yolanda Sánchez Moya

Abstract. In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa), a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006) were estimated from a distributed rainfall-runoff hydrological model (TETIS) using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006) at two stream flow stations, one each in the upper and lower reaches of the catchment. In addition to the modelled flow records, non-systematic flood data were reconstructed using both sedimentary and documentary evidence. The palaeoflood record identified at least 25 large floods during the last 700 yr; with the largest floods reaching a minimum discharge of 255 m3 s−1 (450 yr return period) in the upper basin, and 510 m3 s−1 (100 yr return period) in the lower catchment. Since AD 1925, the flood hydrology of the Buffels River has been characterised by a decrease in the magnitude and frequency of extreme floods, with palaeoflood discharges (period 1500–1921) five times greater than the largest modelled floods during the period 1965–2006. Large floods generated the highest hydrograph volumes, however their contribution to aquifer recharge is limited as this depends on other factors such as flood duration and storage capacity of the unsaturated zone prior to the flood. Floods having average return intervals of 5–10 yr (120–140 m3 s−1) and flowing for 12 days are able to fully saturate the Spektakel aquifer in the lower Buffels River basin. Alluvial aquifer storage capacity limiting potential recharge by the largest floods is a common problem in arid environments, with the largest infiltration volumes favoured by increasing depth to groundwater levels.

Ephemeral key

Return period

Hydrological modelling

Flash flood

10.5194/hess-15-1185-2011

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Citations (34)

New palynological and isotopic data for the Triassic of the western Cantabrian Mountains (Spain)

Journal of Iberian Geology (2009)

Alfonso Sopeña Yolanda Sánchez Moya Eduardo Barrón

Ladinian

Peninsula

Marine transgression

10.5209/jige.33880

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Propuesta de monitorización instrumental para la geoconservación del LIG “icnitas de reptiles triásicos” en el Geoparque de la Comarca de Molina-Alto Tajo (Guadalajara)

Andrés Dı́ez Herrero J. Luengo Juana Vegas Salamanca Marta Hernández García Luis Carcavilla Urquí

A new instrumental monitoring proposal installed in the outcrops of Triassic sandstone with reptile ichnites geosite, located in the Molina- Alto Tajo UNESCO Geopark (Guadalajara, Central Spain), is presented. The system consists of: a continuous record tipping bucket rain gauge with digital datalogger; a dual sensor thermometer (to measure the air temperature and the temperature of the surface of the rock inside a rock-joint) that collect data every fifteen minutes; and a precision analogic jointmeter with millimeter dial. The purpose of this system and the data it registers, is to provide values for the characterization (frequency and magnitude) of the active processes that can degrade the heritage values of the geosite; such as the physic-chemical weathering of the rock holder by gelifraction; that is to say, freeze-thaw cycles occurring when the rock-joints and pores of the rock are filled with water what can enlarge the rock-joints that limit the blocks of the ichnites, producing their rockfall and rupture. This would allow to establish geoindicators to be used for monitoring the conservation status of the geosite and its temporal evolution, which will help the management by the competent administrations.

Rockfall

Thermometer

Outcrop

Rock shelter

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