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El presente trabajo analiza el uso de funciones matemáticas geocronológicas para el establecimiento de marcos cronológicos teóricos en el análisis de diferentes procesos acaecidos durante el periodo Cuaternario. El progresivo aumento de dataciones absolutas obtenidas mediante diferentes métodos (C14, TL, OSL, ESR, TH/U, Cosmogénicos, etc.) de yacimientos arqueológicos, sedimentos y formas del relieve (p.ej.: terrazas fluviales) hace posible el desarrollo de funciones geocronológicas cada vez más precisas. Entre las más utilizadas se encuentran las funciones de distribución de probabilidades de fechas C14 (SPD y SPDR), funciones de frecuencias acumuladas y funciones de regresión (lineales, potenciales, logarítmicas y polinómicas). En este trabajo nos centramos en las dos últimas indicando su creciente utilidad para la determinación de periodos de sedimentación, erosión, formación de suelos y su comparación con curvas paleoclimáticas derivadas de análisis isotópicos (p.ej. O18), así como la utilización de regresiones logarítmicas y polinómicas de diferente orden para el establecimiento de marcos cronológicos en la evolución de valles fluviales en función de la altura relativa de sus sistemas de terrazas.

This work presents a macroseismic analysis of the AD 1755 Lisbon Earthquake-Tsunami event by means of the combination of intensity data derived from the EMS-98 scale and the ESI-07 scale (Environmental damage). About 600 records of secondary earthquake environmental effects (EEEs) for the whole Spain have been used to define intensities, focused on the SW portion of the Iberian Peninsula. The Spanish data have been complemented with 308 EEEs records from Portugal. The analyses indicate maximum intensities of X EMS-ESI along the Atlantic margin of the Iberian Peninsula with 76 records of Tsunami environmental effects (TEEs). An important amplification (VIII – VII) occurred all along the Guadalquivir basin and the adjacent Betic front at epicentral distances of 300–700 km. In these zones 55 records of ground effects (ground cracks, Liquefactions and slope movements) are catalogued. In the rest of the territory of the Peninsula the most widespread effects were hydrogeological changes with 505 records in Spain and 196 in Portugal (total 701 records) covering all the intensity levels. Increase of flow discharges in springs and elevation of water level in wells was the common groundwater response to seismic shacking, especially in SW Iberia. In this zone water elevation in wells was between 5 and 3 m and persistent increases of discharges long-lasting (several days to two months). Persistent discharges on springs were linked in 143 cases to important SW-NE crustal faults (e.g., Alentejo-Plasencia Fault). From the Intensity distribution the historic seismic scenarios are explored by means of the development of empirical ShakeMaps. These consider the three classical seismic sources proposed for this earthquake: Gorringe Bank (G); Marques de Pombal Fault (M) and Atlantic delamination beneath the Gulf of Cadiz (C). However, individually these seismic sources are too small and unable to generate the resulting seismic scenario depicted by the intensity map developed in this work, with onshore seismic accelerations (PGA) up to 0.82 g. These acceleration values and the great amplification experienced throughout the Guadalquivir basin (0.34–0.52 g) are only possible considering a combination of the three seismic sources (GMC Source) probably related to shallow subduction or lithospheric delamination beneath SW Iberia and the Gulf of Cadiz. This will suggest an NNE-SSW offshore rupture length of 350–360 km with an overall rupture area of c. 84,500 km2 resulting in an event magnitude 8.6 Mw calculated from empirical relationships. The results demonstrate the efficacy of these kind of approaches for better identifying and modelling seismic sources for historical events, This work was supported by the Spanish Research Project MINECOFEDER CGL2015-67169-P (QTECSPAIN - USAL). It is a contribution of the Earthquake Geology Group (TPPT) of the INQUA TERPRO Commission. Authors are grateful to the constructive comments of Joao Fonseca and an anonymous reviewer who significantly improved the content of this paper

This study presents a multidisciplinary approach to the tectonic geomorphology and history of the Palomares strike-slip fault in the Eastern Betic Cordillera (SE Spain). Analysis combines geomorphological mapping of fan-surfaces, pedological studies of faulted sedimentary successions, geoelectrical prospection and typical paleoseismological routines of structural analyses. Combined application of these methods together with the existing geochronological databases offer probable paleoclimatic and paleoseismic scenarios for the zone from Middle Pleistocene to Holocene. This study segments the Palomares Fault (PLF) in three overlapping “en echelon” N–S trends (PLF1, PLF2, PLF3). The older PLF1 controls the main faulted Almenara-Almagro range fronts. The younger PLF2 cuts and beheads crusted fan surfaces in the Aljibejo zone (ABJ). The intermediate PLF3 controls the development of intervening tectonic reliefs and offset paleosol sequences in alluvial-colluvial deposits. Our analysis focuses on the PLF3 at the La Escarihuela site (ESCH), where outcrops display eight faulted paleosols developed on overlapped Middle Pleistocene colluvial-alluvial deposits, with variable vertical slip of between 21 and 12 cm (bulk accumulated offset: 33 cm), evidence of two surface faulting events. After the structural analysis of the fault planes (striae plunges) net left-lateral displacements of 120.9 ± 3.3 cm (Event 1) to 69.1 ± 5.2 cm (Event 2), associated with maximum magnitudes of c. 6.7–6.5 Mw. However, the faulted sequence is sealed by a thick mature calcrete horizon of similar characteristics to that faulted at the ABJ1 site. Regional chronological data on calcic soils and calcretes in SE Spain assign this mature calcrete to Oxygen isotopic stages (OIS) 9 (c. 300 ka). With this age fixed at the uppermost of the faulted paleosol sequence at the ESCH site (PLF3), soil development features (clay and carbonate contents, thickness, reddishness, etc.) were used as paleoclimatic proxies to correlate soil horizons with conventional OIS. Correlation indicates that clayey Bt soil horizons primarily occurred during warm isotopic stages followed by recalcification and carbonate accumulation (Btk; Bk; Ck horizons) during latter warmer stages. A proposed theoretical geochronological framework suggests that the sedimentary sequence at the ESCH site (PLF3) was deposited between OIS 18 and 9. Major environmental change towards the present semi-arid climate occurred during OIS 13 (c. 500 ka). During this same stage, paleoseismic event 1 also occurred, but paleoseismic event 2 took probably place during OIS 10 (c. 350 ka), before development of the uppermost calcrete sealing the deformation in this fault segment. However, this OIS 9 calcrete is faulted in the ABJ1 and a younger less developed calcrete is faulted in ABJ2 on the PLF2 segment. Chronology proposed in this paper suggests theoretical ages for these events of between OIS 8-OIS 5 for ABJ1 (c. 200 ka) and between OIS 4 -OIS 2 for ABJ2 (c. 40 ka). This last paleoseismic event triggered major landscape changes with still-visible fault scarps, linear tectonic reliefs, alluvial fan beheading and active drainage shuttering. This present work illustrates the use of soil/paleosol analyses in paleoseismology as a useful tool to build paleoclimatic analogues and develop relative chronological frameworks from existing regional age data.

The Malaga basin contains an important geological record documenting the complex paleogeographic evolution of the Gibraltar Arc before, during and after the closure and desiccation of the Mediterranean Sea triggered by the “Messinian Salinity crisis” (MSC). Proxy paleo-elevation data, estimated from the stratigraphic and geomorphological records, allow the building of quantitative paleogeoid, paleotopographic and paleogeographic models for the three main paleogeographic stages: pre-MSC (Tortonian-early Messinian), syn-MSC (late Messinian) and post-MSC (early Pliocene). The methodological workflow combines classical contouring procedures used in geology and isobase map models from geomorphometric analyses and proxy data overprinted on present Digital Terrain Models. The resulting terrain quantitative models have been arranged, managed and computed in a GIS environment., Departamento de Geología, Universidad de Salamanca, España, Instituto Geológico y Minero de España, España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Departamento de Geología, Universidad de Alcalá de Henares, España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España

One of the most important geological effects generated by the seismic events of Emilia Romagna (Italy, 2012) was the liquefaction. The first earthquake took place on 20th May (5.9 Mw) and generated liquefaction in the locality of San Carlo, mainly recorded as large fissure sand volcanoes. Detailed stratigraphic and sedimentology analyses of these sand bodies indicated the assemblage of rhythmic normal graded beds of sand for many individual sand volcanoes. This is interpreted as repeated individual sand extrusions generating polygenetic sand blows for a single earthquake. This original analysis, made for first time in a case of extensive seismic liquefaction, indicates that the different pulses sand extrusion occurred after seismic shaking, and therefore no related to the cyclic seismic shearing stimulated by surface seismic waves. Underground liquefaction of shallow sandy layers and ground cracking, assisted by relevant lateral spreading, promoted water and sand ejections (E–W direction). Localised and repeated ground subsidence and bulging supported by the ejection of the underlying fluidized sediments feedback transient ground undulations and repeated sand ejections. The unstable undulating behaviour of the ground reinforced and sustained the liquefaction process through time after the seismic shaking, leading the occurrence of polygenetic sand volcanoes. In summary, the seismic liquefaction is the starting point of the process, although only if these sand ejections could promote the instability of the ground since underground sand depletions feedback the liquefaction process through time. The process stops when the hydrostatic balance is recovered in the affected zone.

by Witold Zuchiewicz and Jerzy Zasadni (2012) intended for this volume YOUNG TECTONICS OF THE OUTER WESTERN CARPATHIANS IN THE LIGHT OF SOME MORPHOMETRIC INDICES In this paper, we test the applicability of some morphometric indices commonly used in tectonic-geomorphological studies to the area of the Outer Western Carpathians representing an Alpine fold-and-thrust belt. This belt was shaped largely in Miocene times and shows traces of Pliocene-Quaternary tectonic activity consisting mainly in some remnant folding and faulting. This is indicated by scarce examples of faulting within Quaternary strata, numerous cases of clast fracturing owing to palaeoearthquakes of relatively large magnitudes, as well as warping and tilting of Pleistocene and Holocene strath terraces. Analysis of selected morphometric indices (valley floor width-valley height ratio, riverbed gradients, stream length-gradient index, basin elongation ratios and others), conducted for the entire region and some chosen test areas in the westernmost part of the Outer Western AC C EP TE D M AN U SC R IP T ACCEPTED MANUSCRIPT 24 Carpathians, proved their usefulness in detecting zones showing tendencies to young surface uplift. However, in the case of the stream length-gradient index (SL, Hack’s index) a word of caution should be added, since the index is extremely sensitive to lithologic contrasts in the bedrock and its applicability to young tectonic analysis of fold-and-thrust belts appears to be strongly limited. Dr Andrzej Piotrowski, apiot@pgi.gov.pl, Szczecinie Panstwowy Instytut Geologiczny, Szczecin, Poland and Dr Klaus Reicherter, RWTH Aachen University, Germany

Normally in paleoseismology, the study of the tectonic slip-rate is performed in trenches on the fault scarp, or by the estimation of fault movements from the geomorphic features. In this work, we have carried out a paleoseismic analysis of the Benis Fault, located in southeast Spain, combined with a geothermal analysis inside a deep cave related to the fault (−350 m). Thus, we have estimated the last earthquake magnitude and time of occurrence from evidence of ceiling collapse and displaced carbonate blocks inside a cave, which is developed across the fault. The magnitude was obtained from the application of the empirical relationship of the fault parameters and coseismic vertical displacement, yielding a value ranging between M 5.9 and M 6.5. Moreover, we dated this paleoearthquake by the paleontological record of a “Lynx pardinus spelaea”, with an age of 65 ± 18 ka BP. Additionally, we have measured the thermal profile of the Benis Cave (−350 m of depth), from single rock point temperature measurements during 2 years. The temperature profile shows three different parts inside the cave, the shallow heterogeneous thermal zone till 50 m depth; the homogeneous thermal zone 150 m till with constant temperature and the hetero-thermal deep zone, deeper than 150 m and till the deepest zone (350 m). Furthermore, we have estimated the Vertical Geothermal Gradient, 1.85 °C/100 m for the deepest zone (−150; −290 m). The temperature increases with depth, showing a reverse thermal profile in comparison with normal gradients in deep caves. Finally, we have calculated the heat flux of 0.46 mWm., This work is a contribution of the Spanish projects SISMOSIMA CGL2013-47412-C2-2-P and CGL2015-67169-P (QTETCSPAIN-USAL), granted by the MINECO-FEDER Spanish Ministry.

We are very grateful to all the referees for their indispensable and unselfish work that greatly contributed to the improvement of the quality of the papers. The Department of the Environment and the Department of Science, Technology and University of the Aragón Government, as well as the Innovation Ministry of the Spanish Government (CGL2011-12465), provided financial support to organise the scientific meeting “Geomorphological Research in Spain” (Zaragoza, September, 2011). We thank the International Association of Geomorphologists (IAG), the Spanish Society of Geomorphology (SEG), and the Spanish Society of Quaternary Studies (AEQUA) for supporting the initiative. We are also very grateful to Dr. Cinta Marín for helping with the preparation of the bibliometric data and supplementary material presented in this guest editorial.

The Arriaga Palaeolithic sites, located within the Middle–Late Pleistocene thickened terrace (TCMZ: + 18–22 m) of the Manzanares River valley (Madrid, Central Spain), were subject to intensive archaeological and palaeontological prospecting during the 1980s. Compilation of documents from these old excavations, together with new geoarchaeological, sedimentological, pedological and geophysical data, allow us to locate the morpho-stratigraphic position of the analysed sites within the overall stratigraphy of the TCMZ. This thickened terrace comprises two main fluvial sequences (Lower and Upper) topped by a thick (2.5–5 m) alluvial–colluvial formation. The fluvial sequences are stacked in the study site located in the lowermost reach of the valley, but display complex inset relationships upstream, where they are individualized in two different terrace levels at + 18–22 and + 12–15 m. Terrace thickening was primarily controlled by synsedimentary subsidence caused by dissolution of the evaporitic substratum and locally influenced and backfed by tectonic activity. The regional analysis of the dated (TL and OSL) fluvial sequences containing Palaeolithic sites within the TCMZ, together with new TL dates provided in this study, indicate that the three sedimentary sequences in the TCMZ are time-transgressive valley-fill bodies. Terrace thickening started before the Last Interglacial Period (MIS 6 or older) and continued during whole MIS 5 (lower fluvial sequence) and MIS 4 (upper fluvial sequence) reaching the MIS 3 (top alluvial formation), the latter characterized by the accumulation of alluvial–colluvial sequences derived from the main tributaries and valley slopes. The TCMZ records the Middle–Late Pleistocene boundary, but also the transition between the Lower and Middle Palaeolithic periods during the Late MIS 5 (ca. 96 to 74 ka). The studied Arriaga sites contain evolved Lower Palaeolithic industry (evolved Acheulean techno-complexes) and warm faunal assemblages located within the Lower fluvial sequence, but apparently well constrained Middle Palaeolithic sites are placed within the Upper fluvial sequence at other upstream locations. Deposition of the thickened alluvium was mainly controlled by the upstream advance of dissolution-induced subsidence phenomena, blurring the impact of Late Pleistocene climatic cycles and producing time-transgressive longitudinal valley-fill bodies (i.e. sedimentary sequences). Late Quaternary climatic changes only seem to control the incision/aggradation cycles after the termination of the TCMZ from the Late MIS 3. Dates related to the development of younger inset terraces indicate that they are apparently linked with cold Heinrich events H4 to H1. These younger inset terraces yield cold faunal assemblages and abundant Middle Palaeolithic “Mousterian” assemblages, Departamento de Geología, Escuela Politécnica Superior de Ávila, Universidad de Salamanca, España, Departamento de Arqueología, Paleontología y Recursos Culturales, Auditores de Energía y Medio Ambiente, S.A., España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Dirección General de Patrimonio Histórico, Comunidad de Madrid, España, Técnicas Geofísicas S.L., España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España, Área de Investigación en Peligrosidad y Riesgos Geológicos, Instituto Geológico y Minero de España, España

Soils are non-renewable resources and therefore must be conserved, particularly in protected natural areas. Correct and rational planning of human activities in fragile conservation landscapes should be based on detailed studies of soil-forming factors, such as climate, geology (lithology and surficial deposits), geomorphology (topography, morphology, slope and hydrology), biology (vegetation and human activity) and time and their relationships with the landscape and landforms. This study analyses the geospatial distribution of different soil units in the natural areas of “Las Batuecas-Sierra de Francia” and “Quilamas” and is based on a soil sampling field programme and textural analyses that resulted in soil association maps, dominant soil maps and toposequences that could be extrapolated to natural resource and environmental problems (natural and/or human). In this study, a set of GIS-based digital maps was developed to illustrate the physical attributes of these natural areas. In particular, georeferencing of the various soil-forming factors was used to generate a specific soil map for each natural area and to create a geospatial database, including fact sheets and photographs, of characteristic soil profiles. This soil information was converted into the “kmz” format to geospatially visualise the various soil units in 3D virtual tours using viewers, such as Google Earth, to obtain information regarding the spatial referencing and elevation of the area, interact with the 3D modelling of the tour in Google Earth, overlay the soil map on the orthophoto, activate or deactivate the visible layers, modify the spatial resolution of every point by zooming in or out and obtain the numeric and graphical information for every stop. This soil map can be used in multidisciplinary approaches by adding other thematic layers: lithology, geomorphology, topography, morphology, slope, hydrology, vegetation, et cetera, which would facilitate decision-making by managers and directors of nature areas/parks., Ministry of Economy and Competitiveness: Projects CGL2012-33430/BTE and CGL2012-37581/BTE.

The Strait of Gibraltar area is part of the western Eurasian-African convergence zone characterized by a complex pattern of deformation, including thrusting and folding and active normal faulting. Generally, the area is of low-seismicity; only some minor earthquakes have been recorded in the last hundred years. Archaeoseismological data evidences earthquake destruction occurring twice during Roman times. A better neotectonic framework and knowledge on the paleostress evolution of the Strait of Gibraltar area is necessary to find the local sources for those events and to establish an understanding of the recent deformation. Paleoseismic evidence for one moderate earthquake event around 6000-5000 BP along the normal Carrizales Fault is described in this paper. Off-shore high-resolution seismic investigations, structural and paleostress data, high-resolution GPR and geoelectrical resistivity measurements, outcrop investigations and trenching studies are discussed. The data reveal that active faulting takes place along N–S trending normal faults. Hence, N–S directed normal faults in the area are claimed as local candidates for moderate earthquake activity. Return periods of moderate earthquakes in the order of at least 2000–2500 years in the study area may have to be taken into account. Structural data, such a paleostress data and joints are presented and a deformation history for the Strait of Gibraltar area in southern Spain is developed in this study.

Many on-shore studies focused on high energy marine events occurred in the Gulf of Cadiz have been published since the 1990s. Most of the findings came from sedimentary, palaeontological and geomorphological records on estuaries, marshes, beach-barriers (spit-bars), and some coastal lowlands. Recent off-shore investigations in SW Iberia considered turbidite deposits as a proxy to recognise palaeoearthquakes in this zone. The comparison of datasets from both on-shore and off-shore records indicate that at least five tsunami events generated by strong earthquakes affected this area during the last 7000 years, previous to the more recent and well-documented 1755 AD Lisbon earthquake tsunami event. The catalogue of Holocene palaeotsunami presented here is supported by geological and geomorphological evidences, but also for archaeoseismic and palaeoseismic evidence and written reports for the more recent events occurred during historical times. The recurrence interval for these catastrophic events can be bracketed between 1200 and 1500 years., The research was funded by Projects EU NEAREST, CGL-2008-4000/BTE, CGL-2008-3998/BTE, GRACCIE (CSD-2007-00067) and ACI2008-0726. It is a contribution to IGCP Projects 588 and 567 and of the INQUA Focus Area on Palaeoseismicity and Active Tectonics.

Palaeontological, geomorphological and sedimentological data supported by isotopic dating on Oxygen Isotopic Stage (OIS) 5e deposits from the Spanish Mediterranean coast, are interpreted with the aim of reconstructing climatic instability in the Northern Hemisphere. Data point to marked climatic instability during the Last Interglacial (OIS 5e), with a change in meteorological conditions and, consequently, in the sedimentary environment. The oolitic facies generated during the first part of OIS 5e (ca. 135 kyr) shift into reddish conglomeratic facies during the second part (ca. 117 kyr). Sea surface Temperature (SST) and salinity are interpreted mainly on the basis of warm Senegalese fauna, which show chronological and spatial differential distribution throughout the Western Mediterranean. Present hydrological and meteorological conditions are used also as modern analogues to reconstruct climatic variability throughout the Last Interglacial, and this variability is interpreted within the wider framework of the North Atlantic record. All the available data indicate an increase in storminess induced by an increase in the influence of north-westerlies, a slight drop of SST in the northern Western Mediterranean, and an important change in meteorological conditions at the end of OIS 5e (117 kyr). These changes correlate well with the decrease in summer insolation and with the climatic instability recorded in North Atlantic high latitudes., Research financed by Spanish Projects CGL-2005-04655/BTE, and CGL-2005-01336/BTE; Consolider—Ingenio 2010 GRACCIE. This paper is a contribution to IGCP Project 495 (Quaternary Land-Ocean Interactions: Driving mechanisms and Coastal Responses) and INQUA Coastal and Marine Processes Commission. Our acknowledgments also to Dr. Delminda Moura and anonymous referee who greatly helped in the improvement of this work.

Coastal response to tectonic activity and eustatic-climate interactions during the Late Pleistocene and Holocene has been analyzed along the Barbate-Trafalgar shoreline. The study area consists of an uplifted platform (La Breña, ∼ 140 m) bounded by two major NW-SE faults that have created two subsiding areas: Meca in the west and Barbate in the east. The areas of subsidence have favoured the accumulation of a thick morphosedimentary sequence consisting of (in ascending stratigraphic order) beach, alluvial, and aeolian deposits, which repeatedly underwent soil-forming processes. This study outlines the palaeogeographical evolution of the area over the last ∼ 140 ka, as deduced from geomorphological mapping associated with a range of laboratory analyses (mineralogical, geochemical, magnetic susceptibility, and soil micromorphology analyses), optically stimulated luminescence (OSL dating), and existing U-Th dating. Special attention has been paid to the alluvial unit, made up of vertically stacked sandy sheet-flood deposits with interbedded red paleosols. OSL ages suggest that sediment supply to the alluvial/coastal environments took place mainly at the end of the two most recent glacial periods (Oxygen Isotopic Stage [OIS] 6 and OIS 3/OIS 2) and during the last interglacial period (end of OIS 5). This means that although alluvial sedimentation took place at times of relatively high sea level, these were not times of highstand because very high sea levels (like the present) allow marine erosion of the distal part of the fans (fan toes), cutting cliffed coasts. The repeated occurrence of paleosols in the alluvial sequence seems to indicate a recurrence of environmental changes that modified the feedback relationships between the catchment and the coastal areas. These changes are recorded in repeated oscillations of soil parameters, and are revealed from the results of geochemical and environmental magnetism analyses. We associate repeated pedogenesis and alluvial sedimentation with the glacial/interglacial global climatic changes due to an oscillating humidity/aridity ratio rather than with cyclicity in thermal regime., This research has been funded by Projects BTE 2002-1065 and BTE 2002-1691; CGL 2005-01336/BTE and CGL 2005-04655/BTE; Consolider - Ingenio 2010 - GRACCIE. It is also a contribution to Projects INQUA “Marine and Terrestrial Processes”, IGCP 495, and UCM Workgroup 910198.

Soil development in central Spain was studied through analysis of soil chronosequences from Tagus and Duero river valley terrace systems, evolved under similar Mediterranean climatic conditions throughout the Pleistocene. The most complete soil–terrace sequence, representative for our study, developed in the Tagus valley (Aranjuez–Toledo–Talavera sector). We present soil textural data for argillic horizons developed in Late to Early Pleistocene soils from five valleys. We derive soil development indices from clay and silt content and thickness of argillic horizons. Global clay content (GCC), clay content (CC) and clay/silt ratio (C/Si ratio), numerical indices related to clay illuviation, reflect soil evolution, explored by multiple regression of soil–terrace height and soil–age. Relative terrace heights above present river thalwegs (i.e. +100 m) were transformed to ages with a “height–age transfer function” on the basis of preliminary statistical geochronological analyses for central Spain. The height–age transfer function, a 3rd order polynomial (R2 = 0.90), based on 60 published numerical ages and paleomagnetic data for terrace sequences:describes the overall trend of valley downcutting for the last c. 2 Ma in central Spain. It assigns numerical ages to terrace levels at different relative elevations; and gives an estimate of standardized ages for the related soils. The explored age–soil relationships, logarithmic functions (R2 > 0.80), are sensitive to parent material clay content (corresponding to geology of river catchments) for most soil indices. Only the clay/silt ratio minimizes this sensitivity, and can thus be used for regional approaches (Tagus and Duero basins; central Spain) whereas the CC index is applicable only to individual river valleys or different river valleys with similar catchment geology (i.e. Tagus Basin). The C/Si ratio illustrates the logarithmic trend of weathering of soil particles into clay over time, the generation of soil textural balances sustaining illuviation processes, and therefore provides an estimate of “soil ageing”, for the implementation of soil chronofunctions for regional analysis of river valleys evolving in similar climatic conditions and with similar base-level history., This work was supported by MINECO research projects CGL2012-37281-C02.01 (USAL) and CGL2012-33430 (CSIC). This is a contribution of the INQUA Focus Group PASTSOILS and the associated INQUA RAISIN Project.

Thick laminar calcrete profiles are common on the surface of the eastern Canary Islands of Lanzarote and Fuerteventura. This paper reports the study of one profile from Lanzarote (Macher profile) and one from Fuerteventura (Tef|¨a profile). These profiles are about 2 m thick. The Macher profile is developed on basaltic host rocks and consists of two main horizons: a lower horizon in which white veins of laminated micrite penetrate cracks, and an upper laminar horizon. The Tef|¨a profile is cumulative and consists, from base to top, of massive, laminar, and massive and laminar-brecciated horizons. Highlighted in the study of these profiles are the presence of ooids, the complex structure of the laminar horizons, and the occurrence of fossil bee nests (Celliforma). Ooids consist of a nucleus of clay, micrite and etched grains coated with envelopes of micrite and clay (mainly palygorskite). Organic films favoured both the precipitation of carbonate and the adhesion of clays when the ooids formed in the soil. The laminar horizons consist of a centimetre-scale alternation of massive micrite with varied amounts of ooids and detrital grains with laminated micrite. This alternation indicates the small-scale periods of sedimentation, erosion and soil formation in the upper part of a relatively stable surface. These small-scale alternations may reflect climatic vegetation changes in which arid periods are represented by micrite with ooids, while laminated micrite reflects a better-developed vegetation of the wet periods. Celliforma occur as ovoid larval cells with more or less rounded bases and a flat top. The cells are about 3 cm long and 1.5 cm in diameter. Their wall is about 5 mm thick, and is commonly laminated. Celliforma is interpreted as fossil nests of solitary bees. Their presence in the laminar horizon is evidence for the existence of a vegetation cover containing angiosperms.

Conventionally, a fall in base level is seen as stimulating incision into the distal zones of alluvial fans. In the Cabo de Gata ranges of southeast Spain evidence exists to the contrary. Two sets of Quaternary coastal alluvial fans demonstrate the interaction between climatically-driven variations in the supply of sediment and eustatically-driven changes in base level. The fans are supplied from Miocene volcanic terrain within which no evidence can be found for major tectonic deformation during the period of fan development. The evolution of the east-coast fans has been affected by variations in sediment supply and changes in sea level. The west-coast fans were buffered from the effects of changes in sea level by coastal barriers. Three phases of past sedimentation can be identified on the fans. These can be differentiated on the basis of field observations of soil profiles (particularly colour of the B horizons and accumulation of CaCO3), and laboratory analyses of sequential iron oxide extractions and magnetic mineral properties. The two earlier (major) sedimentation phases were coincident with global glacials (>ca. 135 ka and ca.85-10 ka, based on the stratigraphy and uranium/thorium dating of the coastal sediments). High sea levels during the intervening interglacial and during the Holocene caused erosion of the distal zones of the east-coast fans which led to channel incision into the fan surfaces. On the west-coast fans no such incision occurred, simply proximal incision by small fanhead trenches. The youngest (relatively minor) phase of fan sedimentation has occurred during the Holocene. These contrasting contexts have produced differing styles of fans, with telescopic fan morphology on the east-coast and stacked morphology on the west-coast fans. The differences are reflected in the fan profiles, with steeper gradients dominating the east-coast fans, and extensive lower gradient distal surfaces on the west-coast fans. Fan morphometry, based on analysis of the residuals from drainage area to fan area and gradient regressions, also differentiates between the fan contexts. The fan building phases appear to be controlled proximally by climatically-driven pulses of sediment supplied to the fans. These occurred during global glacials coincident with low sea levels, and caused fan progradation onto the exposed foreshore. The intervening global interglacials were times of little fan sedimentation, and on the east coast, where high sea levels were able to erode the fan toes, deep through-fan dissection ensued., This research has been partially supported by the British Council/Spanish Government—Acciones Integradas Programme. Diane Spivey helped with some of the field surveying. John Dearing gave help in the interpretation of the mineral magnetic data. We also thank the staff of the Graphics section of the Department of Geography, University of Liverpool for producing most of the illustrations.

The Plio-Pleistocene boundary in the Mediterranean region has been defined by the entry of the so-called 'northern guests'. The absence of this characteristic cold fauna in the sedimentary record of littoral marine basins in SE Spain has led to the local establishment of this boundary by other means. Most outcropping upper Pliocene and Pleistocene marine sediments in this area have a very shallow character, resulting in the absence of the planktonic foraminiferal assemblages that characterize the upper Pliocene. As a result the only means of determining this boundary has been through regional correlation, detailed mapping and sedimentological analysis, as well as palaeomagnetism. After studies were carried out in different basins, and accepting the age of 1.64 (now recalibrated to 1.8) Ma for the Plio-Pleistocene boundary (Aguirre and Pasini, 1985), we conclude that this boundary does not bear any climatic, environmental or tectonic signature. The changes in most of these basins seem to occur either before or after this date.

This study analyses coastal geomorphic responses to the various sea-level changes that occurred throughout the Quaternary period in the Mediterranean and Atlantic coasts of Spain. Particular emphasis is paid to the geomorphic and stratigraphic record of the changes in amplitude, duration and frequency associated with the major gradual climate changes observed in marine cores and ice oxygen-isotope records during the Early and Middle Pleistocene (ca. 2.6 Myr; ca. ~ 1.4–0.8 Myr; ca. ~ 0.4–0.2 Myr) and also with the rapid and abrupt Late Pleistocene and Holocene climate changes. With this aim, the best preserved and most complete sedimentary sequences known in the Spanish Mediterranean and Atlantic coasts covering diverse geodynamic and climatic contexts were selected and analyses. This study is mainly based on field investigation of geomorphic, sedimentologic and stratigraphic features of mapped morphosedimentary units, combined with reliable chronological data. The analyses include the interpretation of sedimentary environments, the 3-D reconstruction of facies and morphosedimentary unit arrangement, paying special attention to the lateral geomorphic relationships between marine and terrestrial morphosedimentary units developed during interglacials under sea-level highstand scenarios. The interglacials occurred during four key Quaternary periods might be related with major gradual changes associated with glacial climate cycles reported from marine and ice oxygen-isotope records. Almost coeval changes in geomorphological styles are reported from all studied areas, regardless of their specific geodynamic context. Results from the Mediterranean realm suggest that this area is more sensitive to climatic and sea level variability than the Spanish Atlantic coast, particularly in the case of rapid and abrupt changes.

One of the key tasks in archaeoseismolo`gy is to test whether the recorded building damage in ancient cities can be related to ancient earthquakes. Archaeologists often claim abandonment, ruin or war instead of natural causes to explain the recorded damage in archaeological findings. This work proposes a comprehensive classification of Earthquake Archaeological Effects (EAE) based on the seismic deformation of buildings and monuments within urban areas of ancient cities. Accordingly, the proposed EAE classification differentiates the seismic deformation on the structure of buildings in two groups: from transient shaking and from permanent ground deformation. The first type of EAE corresponds to fractured walls and fallen key stones in arches, for example. The second type of EAE are tilted walls and shock breakouts of flagstones due to basement failure. To illustrate the proposed EAE classification, examples of earthquake damage on ancient buildings are described: Baelo Claudia and Tolmo de Minateda cities (Roman and Visigothic Periods, 1st–6th century AD, respectively, South of Spain) and Teotihuacan and Tarascan sites (Early Classic ca. IVth century AD, and Upper Post-Classic Period XIIIth century AD, Central Mexico).

We really appreciate the comments by Mauz and Antonioli on our paper (Bardají et al., 2009), but here we respond to the erroneous statements made in their critical reading of our work. We agree with the authors' historic review of the problems raised when effects of tectonics and sea level oscillations are observed in the record of relative sea-level changes in Western Mediterranean. We should not forget that the Mediterranean itself constitutes a collision plate boundary, with few stable areas within it. Therefore, the study of the Last Interglacial shorelines cannot be simply analysed according to altitude, as they say. What we do not share with Mauz and Antonioli is that “the only solution to this seemed to be determining the age of a coastal deposit using radiometric, dosimetric and chemical dating techniques”., Research financed by Projects CGL2008-3998, CGL2008-04000 and GRACCIE-CSD-2007-00067. CHM acknowledges the financial support from the Science and Engineering Research Council of Canada and the UNESCO Chair for Global Change Study of Université du Québec à Montréal. This paper is a contribution to IGCP495 (Quaternary Land Ocean Interactions: Driving Mechanisms and Coastal Responses), INQUA Commission on Coastal and Marine Processes and CM Work Group Paleoclimatology and Global Change (UCM 910198).

Digital analysis of torrential gullies (‘barrancos’) deeply incised into the volcanic Island of Gran Canaria (Canary Islands) allows us to extract the longitudinal profiles and pre-incision surfaces for individual basins, from which morphometric parameters (length, elevation, area, slope) have been calculated. Other derived parameters, such as ridgeline profiles, maximum incision values, volume removed by fluvial erosion, geophysical relief and isostatic uplift, have also been computed. Based on K/Ar ages for the island, well-constrained incision-uplift rates have been calculated by means of the combination of different methodological approaches commonly used in orogens and large mountain ranges. The geomorphological and morphometric analyses reveal that the island is clearly divided into four environmental quadrants determined by the combination of a couple of key-factors: the age of the volcanic surfaces and the climatic conditions. These factors determine a young sector covered with Plio-Quaternary platform-forming lavas (finished at 1.9–1.5 Ma) evolving under contrasting wet (NE) to dry (SE) climates, and an older sector, conserving the residual surfaces of the Miocene shield building (14.5–8.7 Ma) at the ridgelines, also subjected to wet (NW) and dry (SW) climates. Incision is related to the age zonation of the island. Maximum incisions (

Sea level and climate changes archived in various coastal environments during the last part of the last glacial and present interglacial periods are investigated by interpolating available geomorphology, sedimentology, palaeontology and geochronology data. The coastal response to these changes depended on the environment and geographic location. Changes of sea level during the rising, transgressive phase are well recorded in the sedimentary filling of the estuaries, whereas during the phase of highstand they are best recorded in beach-barrier environments. The postglacial rise of sea level took place in two phases: a rapid rise until 6500 cal BP, and a second phase of near stability with minor oscillations of metric magnitude. Regarding climate changes, there is no record of changing temperatures in the coastal zones of southern Spain, although there is in precipitation and wind intensity/velocity. After 7-5 cal ka BP, the general climatic trend towards aridity was punctuated by several short-lived (centennial) episodes of increased aridity that occurred with a millennial cycle, often coincident with Bond cool events and, in some cases, with decreases of sea surface temperatures. The absence of human intervention in vegetation composition until 2000 BP suggests that most environmental coastal shifts were climatically driven., Financial support from Spanish Projects CGL2005-01336/BTE and CGL2005-04655/BTE is acknowledged. This is a contribution to IGCP 495 and to the INQUA Coastal and Marine Processes Commission. C.J.D. is a member of UCM Research Group 910198.

The Lorca alluvial fan (SE Spain) constitutes an excellent example of transition from alluvial to fluvial sedimentary environments in a semiarid region. The fan body represents a large gently-sloping alluvial fan of mainly sandy–silty composition. It is presently dissected throughout its length by the Guadalentín River, which worked as the main fan channel and still operates as a torrential rambla-type channel responsible for historic large flood events. Three different outcrops are analysed at fan-apex, mid-fan and distal-fan locations, taking also into account the different inset terrace levels developed within the main fan trench at + 8–9 m, + 5–6 m, + 3–4 m and + 1–2 m above the present thalweg. Available radiocarbon data and archeological remains collected in fan sediments and inset terraces enable the construction of a preliminary hypothesis about the progressive incision of the fan body from pre-historical to historical times. Proximal fan aggradation took place during the Early Holocene before ~ 7900–7700 cal. yr. BP and continued until the Late Neolithic to Calcolithic Period (~ 5500–4200 cal. yr. BP) when the fan surface stabilised, and channel incision generated a first fanhead trench. Subsequent infilling of the fan trench led to the development of the upper terrace level (+ 8–9 m) which merged with the palustrine environments 23 km downstream of Lorca, feeding distal fan lobes during Late Bronze Age and Post-Roman times. The second terrace level (+ 5–6 m) is a cut & fill episode of about 5 m thickness developed from Roman times, and dated to ~ 1700 to 950 cal. yr. BP. The geometry and altimetry of the upper terrace level, together with the occurrence of different steps in the longitudinal profile of the river at mid to distal fan locations, strongly suggest that the incision of the ancient fan channel was assisted by intersection point headcut development (sensu [Harvey, A.M., 1978. Dissected alluvial fans in southeast Spain. Catena 5, 177–211.]) at proximal-mid fan locations, but by headward erosion exerted by neighbouring drainage basins at distal palustrine environments. Therefore, the Lorca fan exemplifies the behaviour of large-sized fans in its transition from pure alluvial environments to fluvial ones, and its eventual incipient integration into a regional drainage network subject to a dynamic base-level during the historic period., This work has been supported by the Spanish DGES Projects CGL2005-04655/BTE and CGL2005-01336/BTE. The authors are grateful to the constructive comments of Martin Stokes (Plymouth, UK), Francisco Gutiérrez (Zaragoza, Spain), Andy Plater and Adrian Harvey (Liverpool, UK).

This study represents the first paleoseismic approach in Spain in which archaeological remains are considered. The ancient Roman city of Baelo Claudia (1st-4th centuries AD), located at the axial zone of the Gibraltar Strait (Cadiz, south Spain), contains abundant disrupted architectural relics and ground collapses (i.e. landsliding, liquefacion) probably related to historic earthquake damage of intensity IX-X MSK. The archaeological stratigraphy of the city evidence two major episodes of abrupt city destruction bracketed in AD 40-60 and AD 350-395 separated by an intervening horizon of demolition for city rebuilding, otherwise characteristic for many earthquake-damaged archaeological sites in the Mediterranean. The second episode led the eventual city abandonment, and it is evidenced by good examples of column collapse, distortion, failure and breakdown of house and city walls, and pavement warping and disruptions documented during different archaeological excavations, which can be catalogued as secondary coseismic effects. Main damaged relicts observable today are the set of pop-up like arrays and warping developed in the ancient Roman pavement. Their analysis indicate an anomalous westwards ground displacement oblique to the main gentle southward slope of the topography, as also evidence failures, collapses and breakdown of walls and columns, suggesting that stress acted in a broad SW-NE/WSW-ENE orientation consistent whit the expectable motion along the largest NE-SW strike-slip faults of the zone, which in turn can be catalogued as seismic sources of moderate events (ca. 5 mb). Major disruptions and city abandonment were hesitantly related to relatively far strong earthquakes occurred during the late 4th century AD in the Mediterranean or western coast of Iberia by Menanteau et al. [Menanteau, L., Vanney, J.R., Zazo, C., 1983. Belo II : Belo et son environment (Detroit de Gibraltar), Etude physique d'un site antique. Pub. Casa de Velazquez, Serie Archeologie 4., Ed. Broccard, París.]. However, this study indicates that the occurrence of close moderate earthquakes jointly with the unstable character of the ground at the zone (site effect) is a more reliable hypothesis to explain the observed deformations., This work has been supported by the 97-00 Project of the Fund. Ramón Areces, the Spanish DGES Projects BT-02/1065 and BT-02/1691 and by the Acciones Intergradas grant HA2004-0099.

Tectonic activity of SE Spain is evaluated through the application of a general morphometric analysis over 17 different mountain fronts. The selected fronts are distributed along the two most prominent crustal-scale structures of the Mediterranean sector of Spain: The Eastern Betic Shear Zone (EBSZ) and the Valencia Trough. Geomorphic indexes used in this study are Mountain-front sinuosity index (Smf) and Valley floor/width ratio (Vf). This work is largely based on the Smf/Vf regression analysis of the studied fronts together with previous available data from SW USA. The development of mountain fronts in both different lithologies and tectonic contexts enabled characteristic morphometric signatures for different activity scenarios (tectonic activity classes) to be obtained. This study thus indicates that variations of mountain front geomorphology triggered by different styles of faulting can be detected by morphometric analysis. It is demonstrated that discrete uplift rates of 0.15-0.08 m/ka are sufficient to keep relatively low Smf values down to 1.4 in Active fronts (Class 1). Taking into account the reported uplift rates and preliminary palaeoseismic data for some of the Class 1 studied fronts, recurrence periods for surface rupture events can be theoretically bracketed for SE Spain. Recurrence periods for Class 1 fronts could theoretically range between 10,000 and 12,500 years for maximum slip conditions, and 1750 and 2600 years for minimum slip conditions. Inactive fronts (Class 3) develop under uplift rates down to 0.03 m/ka, and tested recurrence intervals for rupture events range between 25,000 and 50,000 years. Class 2 fronts of intermediate characteristics and activity display uplift rates between 0.07 and 0.03 m/ka., This work has been supported by the Spanish DGES Projects PB98-265 (USAL) and PB98-514 (CSIC). The authors wish to thank M. Stokes, R. Basili and A. Mather for useful comments on earlier versions of the manuscript.

An analysis of sedimentation rates during the Holocene in estuaries in the southwestern coast of the Iberian Peninsula using depth/age diagrams reveals the existence of two distinct phases. The first, between ca. 10,000 and 6500 Cal BP, still in the transgressive phase, yields values of sedimentation rates of 5 mm/yr. The second phase extends after the maximum transgressive (ca. 6500 Cal BP) until the present, with sedimentation rates of 1.5-2 mm/yr. These results support the idea that marine sedimentation began during the transgressive phase and continued during the highstand phase, far beyond the time of the transgressive maximum, as postulated in some previous papers., This work has been supported by the Spanish DGES Projects PB98-0514 and PB98-0265 and Fundación Areces Project “Climatic Changes and sea level changes”. It is a contribution to IGCP 437 Project and INQUA Commission on Sea-level changes. J. Lario was supported by a grant from Comunidad de Madrid.

Pleistocene alluvial fan surfaces of the campo de Cartagena-Mar Menor Basin (Murcia, SE Spain) are capped by thick mature calcretes. Calcrete profiles consist mainly of six different horizons: prismatic, chalky, nodular, massive, laminar and coated-gravels. Petrographic study of the calcretes has shown the occurrence of features such as alveolar septal structures, calcidied filaments, coated grains, spherulites, calcified root cells and calcispheres that indicate the biogenic origin of the calcretes, mainly induced by plant root related microbial activity. The calcretes studied were formed initially in the soil and represented the K horizon. Development of the calcrete profiles took place in six main stages and was driven by multiple phases of soil formation, erosion and reworking. The relationships between these processes caused the formation of different calcrete profiles in proximal and distal fan areas. In the distal areas, which are controlled by limited distal fan aggradation, episodic sediment input, buried previusly developed calcretes and generated new space for calcrete growth by plants growing in the overlying unconsolidated materials. this allowed the renewal of calcrete formation and it led to the development of complex composite profiles which are thicker than in proximal areas, where surface stabilisation and/or dissection enabled calcrete reworking and brecciation. These processes of erosion, sedimentation, reworking and renewed calcrete formation initiated by vegetation were repeated through time. They explain the complex macro- and microstructures of these calcretes and indicate that calcrete development, even reaching mature stages, can start before the fan surface is completely abandoned, but it requires episodic sedimentation. Eventually, distal fan aggradation and continuous calcrete development throughout the entire fan surface, led to the ultimate fan surface induration, controlling subsequent landscape evolution. So, fan surface calcretes cannot be envisaged as simple top-surface carbonate accumulations, but as complex feedback systems in which pedogenic, biogenic and sedimentary processes interact in response to the evolving fan-surface dynamics during the turminal phases of fan development in semiarid environments., This study has been supported by the Spanish DGICYT Projects PB95-0946 (USAL) and PB95-0109 (CSIC).

[EN] The evolution of Neogene and Quaternary littoral basins in the Eastern Betic Cordillera is largely related to tectonic activity along the Eastern Betic sinistral shear zone.Detailed mapping of sedimentary units in these basins, together with sedimentologicaland paleomagnetic analysis lead tothe proposal of a new chronostratigraphie frameworkfor Pliocene and Quaternary deposits.This chronostratigraphie setting rejects the synchronous character of the “Pliocene Unite” previously referred toas:“P.I” (grey-blue marls), “P.H” (yellow calcarenites), and “Р.Ш” (variegated silts and clays). Instead, tectonics would have controlled the paleogeographic evolutionof the Eastern Betic realms, causingthe lithofacies to occur repeated in space and time. The Plio-Pleistocene boundary in these basins is not accompanied by changes in geodynamic behaviour or climatic conditions. According to the paleomagnetic data, these changes occurred at different times during the Pleistocene in the different studied basins., [FR] L’évolution des bassins littoraux néogènes et quaternaires dans les Cordillères Bétiques orientales est étroitement liée à l’activité tectonique le long du couloir décrochant sénestre, bétique oriental. La cartographie détaillée du remplissage sédimentale des bassins et les analyses sédimentologiques et paléomagnétiques ont permis d’établir une nouvelle échelle chronostratigraphique pour les dépôts pliocénes et quaternaires. Elle remplace les interprétations antérieures fondées spécialement sur les corrélations stratigraphiques, et abandonne le traitement des unités pliocénes traditionnelles (P.I marnes gris-bleues; P.II grès calcaires jaunes; Pill limons et argiles bigarrés) en tant qu’unités isochrones. L’évolution paléogéographique de la région, contrôlée particulièrement par la tectonique, a entraîné le déplacement et la répétition des faciès dans l’espace et dans le temps. La limite Plio-PIéistocène dans les bassins n’est pas acompa-gnée par des changements du comportement géodynamique ni des conditions climatiques. D’après les données paléomagnétiques, ces changements ont eu lieu dans les divers bassins à différents moments du Pleistocène.

Neotectonic behaviour of the Eastern Betics (southeastern Spain) has been controlled by the presence of a large, left-lateral shear zone. This is an intraplate transcurrent zone, probably decoupled by a mid-crustal detachment horizon. The morphological expression of this crustal structure is a sigmoidal corridor in which the main Quaternary basins are located. Three types of morphostructural domains can be distinguished in the sigmoidal corridor: the central segment, and the northern and southern terminal splays. The central segment is characterized by wrench tectonics, whilst the southern and northern terminal splays are controlled by transtensional and transpressional tectonics, respectively. The Quaternary morphostructural pattern is only the more recent picture of the tectonic processes that have controlled the late orogenic evolution of the Eastern Betics: the indentation of the Aguilas arc, accompanied by thin-skinned thrusting and tectonic escape in its easternmost sector; and extensional collapse, accompanied by thin-skinned stretching, in its westernmost sector.

The Guadalentín Depression, located in SE Spain (Murcia Region), is bounded by two of the main NE-SW master faults of the Eastern Betics Cordilleras: The Lorca-Alhama and the Palomares left-lateral strike-slip faults. Available earthquake data indicate that, in the last 600 years, some sectors of the Lorca-Alhama Fault and the entire sector of the Palomares Fault have not been associated with significant historical seismicity. However, they show a wide range of diagnostic features of earthquake surface displacements on late Pleistocene and Holocene alluvial and colluvial surfaces. Aside from the left-lateral offsets recorded along 045-050° master fault strands of the Lorca-Alhama Fault, major paleoseismic surface displacements show different kinematics in relation to the broad orientation of the fault strands: (1) vertical normal displacements along 010-020° trending faults mainly preserved as degraded fault scarps of 2.5-1.8 m high (Aljibejo site); and (2) vertical reverse displacements, with average offsets of 0.2-1 m, along 065-080° subsidiary faults. In this last group, the younger one (Carraclaca Baths site) remains as a fault scarp of 0.8 m height affecting a cascade tufa which was active until the Spanish Roman Period (2nd Century B.C. to 6th Century A.D.). In other cases, reverse offsets resulted in smaller displacements (0.26 m) of paleosols, but show a recurrent behaviour (La Escarihuela site). The strongest earthquakes recorded in the study area did not exceed more than Mb 4.5 or MSK Intensity VIII (historical) with no evidence of coseismic rupture. Therefore, the preliminary data presented here seem to indicate that the paleoseismic activity on both faults is capable of producing coseismic surface displacements, probably reaching magnitudes of at least 6.5. These data show that paleoseismic studies based on geomorphological analyses are a useful tool in the assessment of the relative degree of activity of apparently 'aseismic' fault traces., Thisw ork has been supportedb y the DGICYT Spanishp rojectsP B92-282( University of Salamancaa)n dP B92-0023(Museo Nat. CC. Naturales C,S IC). The authoras reg ratefutlo theN ationaSl eismological Survey( IGN) for accesst o the seismicd ata-bas(eO rder9 6/0002)a,n d gratefullya cknowledgDe r A.M. Michetti (ANPA, Rome) for his valuables uggestionisn the preparatioonf this paperT. he commentas nd criticismo f two anonymourse viewersa lsoh elpedim provem ep aper.