L. E. Arlegui

University of Zaragoza | UNIZAR · Department of Earth Sciences

Download the celadas.gltf file and open it on your preferred pdf viewer. With your mouse you can tilt, rotate and zoom into the representation of seismic foci. Size scales to magnitude

The stability analysis of rock slopes holds paramount importance in a multitude of geotechnical projects, including rock-fill dams, embankments, as well as natural and excavated slopes. Among the various failure modes encountered in rock slopes, planar failure is a significant concern. Numerical analysis employing the Mohr-Coulomb linear criterion...

Úcar's criterion can be employed in the "predictive mode" during the initial stages of a pro-ject to determine the parameters for the strength equations using simple compression and tensile tests (such as Direct Tensile or Brazilian tests), yielding a reliable estimate. As the project progresses to more advanced stages, it is generally recommended...

Estudios y pruebas sobre la resistencia en macizos rocosos demuestran que la envolvente a los círculos de Mohr es una curva plana cuya tangente cambia de posición en función del intervalo de esfuerzos. En la presente investigación se estudia la estabilidad en macizos rocosos mediante los criterios de rotura no lineales de Úcar y de Hoek y Brown, y...

This is a spreadsheet implementing the algorithms presented in the companion paper. Requires the complement SOLVER to be installed. Instructions in the paper and a succinct version in the spreadsheet.

This is a spreadsheet implementing the algorithms presented in the companion paper. Requires the complement SOLVER to be installed. Instructions in the paper and a succinct version in the spreadsheet.

This work proposes the calculation of the factor of safety for a strongly jointed rock mass in the case of plane failure with a tensile crack whose exact position or depth is not known but is expected to exist. This calculation is performed by applying the non-linear failure criteria of the Focus Procedure of Úcar and Hoek–Brown’s and implementing...

The Calamocha fault is an 18-km-long, NNW–SSE striking pure normal fault that moves down the northern sector of the Jiloca graben with respect to the Neogene infill of the Calatayud basin (central Iberian Chain). Its structure and kinematics are characterized by means of detailed geological mapping, morphotectonic analysis and data recording at the...

The NNW-SSE trending Sierra Palomera fault is characterized as an active, nearly pure extensional fault with mean transport direction towards N230°E, consistent with the ENE-WSW extension trajectories of the recent to present-day regional stress field. Its macrostructure is described from surface geology and magnetometric and electromagnetic survey...

The E–W trending, nearly pure extensional Valdecebro fault zone is a transverse structure at the central sector of the N–S Teruel graben. It was activated by the Late Ruscinian (Early Pliocene, ca. 3.7 Ma), giving rise to structural rearrangement of the graben margin. Until the Late Pleistocene, it has accommodated a net slip ca. 205 m, with slip r...

The Teruel Basin is a NNE-SSW trending intracontinental extensional basin located in central-eastern Iberia. It is asymmetrically bounded to the east by a major fault zone, but intrabasinal faults with diverse orientation (NNE-SSW to NE-SW, E-W, or NW-SE) also appear. Offsets of the successive sedimentary units and of two planation surfaces reveal...

The relationship of independence, interaction or linkage between two neighbouring intraplate active extensional faults, the Teruel and Concud faults, are investigated from structural and paleoseismological data, and the results are discussed to improve seismic hazard assessment for the region. This paper provides the structural and paleoseismologic...

The Concud Fault is a ~14-km-long active fault that extends close to Teruel, a city with about 35,000 inhabitants in the Iberian Range (NE Spain). It shows evidence of recurrent activity during Late Pleistocene time, posing a significant seismic hazard in an area of moderate-to-low tectonic rates. A geophysical survey was carried out along the mapp...

The recognition of seismically-induced soft-sediment deformation structures (SSDS) in sedimentary successions characterized by different facies, and hence by different rheology, is challenging. This is the case for high porosity and high permeability aeolian facies interbedded with muddy wet interdune deposits and alluvial conglomerates and sandsto...

A new trench excavated at the southern sector of the Concud Fault provided evidence of three palaeoseismic events dated to ca. 21, 18 and 13–3 ka BP, respectively. The two youngest ones had not been detected in previous studies. The results extend the total recorded palaeoseismic succession for the fault: eleven events since ca. 74 ka BP to the pre...

Ground penetrating radar surveys (GPR) present numerous application fields due to its high resolution and depth range depending upon the used central frequency antennas. Both penetration and resolution permits the study at scales between milimetric to decametric range. The evaluation of research objectives permits the choosing of high to low freque...

In palaeoseismological trench studies, precise correlation of sedimentary units between fault blocks has an unquestionable value for accurately inferring the amounts of coseismic displacement and hence for assessing seismic hazard. A methodology based on laser analysis of particle size and mineralogic composition by X-ray diffraction is proposed in...

Several faults in the Teruel and Jiloca grabens (Iberian Chain, NE Spain), particularly the targeted Concud fault, show evidences of recent, continuous activity, despite their scarce instrumental and historic seismic record. Three trenches are studied in two locations (central and southeastern sectors of the Concud fault, respectively). After compa...

y-gRaph, a user-friendly spreadsheet for reconstructing paleostress fields by means of the y-R diagram is presented. The y-R diagram is based on Bott´s equation and translates the parameters of the stress ellipsoid to a XY plot representing the maximum horizontal stress orientation (σy) and the stress ratio (R), compatible with a given set of stria...

Resumen: La prospección magnetométrica y electromagnética, junto con datos geológicos de superficie, ha permitido caracterizar una estructura compleja en el borde oriental activo de la fosa del Jiloca. Paralelas a la falla de Sierra Palomera, aparecen dos alineaciones de fallas normales localizadas hacia el interior de la fosa, una antitética y otr...

The study of active faults in intraplate areas presents some handicaps due to their typically wide interseismic periods, being their importance very often overlooked within the instrumental and historical record of seismic events. In such cases, seismic activity must be assessed from paleoseismic record studies. Large recurrence intervals also sign...

Among the conspicuous extensional structures that accommodate the onshore deformation of the Valencia Trough at the central-eastern Iberian Chain, a number of large faults show evidence of activity during Pleistocene times. At the eastern boundary of the Jiloca graben, the Concud fault has moved since mid Pliocene times at an average rate of 0.07-0...

An aeolian dune field migrating to the east encroached on the toes of alluvial fans in the Teruel Basin (eastern Spain) during a short interval in the Late Pliocene (ca 2·9 to 2·6 Ma), when Northern Hemisphere glaciation and strong glacial–interglacial cycles began. Preservation of the dune field was controlled by syn‐sedimentary activity of a norm...

La Base de Datos de Fallas Activas de Iberia (QAFI) es una iniciativa del Instituto Geológico y Minero de España (IGME) para construir un repositorio público de información científica sobre fallas con actividad en los últimos 2,6 Ma (Cuaternario). Además, la QAFI persigue facilitar la transferencia de conocimiento geológico al ámbito tecnológico de...

Quaternary Active Faults Database of Iberia (QAFI) is an initiative lead by the Institute of Geology and Mines of Spain (IGME) for building a public repository of scientic data regarding faults having documented activity during the last 2.59 Ma (Quaternary). QAFI also addresses a need to transfer geologic knowledge to practitioners of seismic haza...

This reply tackles the three main points of discussion of the comment, carefully distinguishing those constructive contributions from the potentially confusing ones. (1) We accept that we should have utilised previously published datings of the middle terrace, even if we consider them to be less reliable than the used ones, so broadening the slip-r...

Resumen: En este trabajo se realiza una prospección geofísica con diversas técnicas en el sector de El Hocino, al NW de la ciudad de Teruel, con el objetivo de localizar una de las ramas en que se desdobla la falla de Concud (límite NE de la fosa del Jiloca), en una zona donde no aflora en superficie. En el sector de la falla se identifica una anom...

The Concud fault is a 13.5km long, NW–SE striking normal fault at the eastern Iberian Chain. Its recent (Late Pleistocene) slip history is characterized from mapping and trench analysis and discussed in the context of the accretion/incision history of the Alfambra River. The fault has been active since Late Pliocene times, with slip rates ranging f...

A detailed structural study, combining map information and results of a magnetic, electromagnetic and georadar survey, is carried out in the area where the Concud fault (NW-SE striking, veering towards NNW-SSE at its southern sector) approaches the Teruel fault (N-S striking). Both faults are independent structures from the geometrical and kinemati...

In this work we compare the results of anisotropy of magnetic susceptibility (AMS) with palaeostress analysis at local scale. The AMS data refer to 14 sites from weakly deformed mudrocks (Lower and Middle Miocene lacustrine sediments) from two areas of the internal part of the Ebro foreland basin, the Bardenas Reales and Monegros areas. Nine sites...

Este trabajo analiza, desde múltiples puntos de vista, la problemática del karst en yesos en el entorno de Zaragoza, el desarrollo de dolinas aluviales y los riesgos que éstas conllevan. La morfología de las dolinas depende del comportamiento mecánico de la cobertera situada sobre el sustrato yesífero: en coberteras sin cohesión aparecen morfología...

The abundant paleomagnetic and AMS information in the Pyrenees (and their foreland basins; Aquitaine and Ebro) motivated the development of databases in 2003 in the frame of an INTERREG III project (Pyrenean Network, CTP). In this paper we describe the different databases, the methodology used (sources, layers, display) and future developments. The...

Although conjugate fault systems cannot accommodate three-dimensional strain, the notion of stress-driven fracturing based upon Mohr-Coulomb's failure criterium can be reconciled with any kinematic boundary condition if a non-static scenario is considered. The concept of stress partitioning is proposed as a tool for understanding the mechanisms all...

Space and time variations of alluvial karst subsidence in the central Ebro Basin are analysed in trenches (paleodolines), aerial photographs (historical dolines) and field surveys (present-day active dolines). The measured subsidence rates, as well as a comparison between densities of paleodolines computed in randomly selected scan-lines and densit...

The abundant paleomagnetic and AMS information in the Pyrenees (and their foreland basins; Aquitaine and Ebro) motivated the development of databases in 2003 in the frame of an INTERREG III project (Pyrenean Network, CTP). In this paper we describe the different databases, the methodology used (sources, layers, display) and future developments. The...

En este trabajo se estudian estructuras de deformación en sedimentos no consolidados, observadas en depósitos fluvio-eólicos del Plioceno superior (sector norte de la fosa de Teruel) y en terrazas del Pleistoceno medio-superior en la zona de confluencia de las fallas de Concud y Teruel. Se describen morfologías de diques, estructuras en champiñón y...

The integration of palaeostress results obtained from the analysis of non-striated faults and joints affecting Plio-Pleistocene deposits near the Concud fault (southern Jiloca graben, eastern Spain) yields a multidirectional tension stress field (vertical σ1, σ2≈σ3) where the primary σ3 trajectories trend ENE. The results also show strong deflectio...

Many joint surfaces show en échelon arrays of microfractures (fringe cracks, F-joints, twist hackles) along fringe zones in continuity with plumose structures. In layered rocks, joints with two fringe zones showing opposite stepping senses at the top and bottom (type A) are more frequent than those showing a single stepping sense (type P). Consiste...

In a major survey of published palaeostress estimates obtained by the use of fault-slip data, over 2000 stress tensors from shallow crustal levels have been compiled. The results are derived from regions where deformation is dominated by brittle processes, and consist of incomplete stress tensors in which the orientations of the principal stresses...

Geometric and kinematic analysis of Pyrenean folds, cleavage and thrusts is carried out in several exceptional outcrops of the Eocene flysch at Isaba (Navarra, Spain). Distribution, orientation and cross-cut relationships between these structures suggest that they are roughly coeval and co-genetic, the total deformation being distributed into diffe...

Samples of non-striated fracture surfaces within clastic materials of Late Pliocene–Pleistocene age from the Teruel grabens (eastern Spain) have been analysed using a stress inversion method based on observations of slip sense. The results obtained at 21 sites are compared with Late Miocene–Early Pliocene extensional stress tensors previously infer...

By analysing Landsat TM and ERS-1 SAR images, thousands of lineaments have been mapped within the Neogene materials of the central Ebro basin (north-east Spain). Comparison with data from previous field surveys proved that most of them are normal faults. The main trend represented in both systems is NW-SE. However in SAR other trends that correspon...

A simple computer program is described for estimating palaeostress tensors from orientation data from a set of fault planes. The computation is based on a novel technique that allows the tensor to be estimated in situations where directions of slip on the faults cannot be determined, but where the senses of the dip-slip component of slip on the fau...

The following values have no corresponding Zotero field: ID - 277

The Kirthar fold belt (KFB) is one of the N-S-trending portions of the thrust belts of western Pakistan. In the study area (some 150 km north of Karachi), the KFB consists of large-scale, open NNW-SSE anticlines that affect the outcropping Kirthar and Nari formations. From an analysis of more than 200 minor strike-slip and reverse faults from 14 di...

In numerous cases, the use of standard methods of palaeostress inversion from fault slip data is prevented by the absence of structures that indicate the direction of slip on the fault. In such instances, however, the offset of planar markers, such as beds matched in the footwall and hanging wall, often allows the sense of dip separation (normal or...

Three regional joint sets striking N–S, E–W and WNW–ESE affect the Tertiary rocks of the central Ebro basin. From analysis of their chronological relationships and spatial distribution, it is concluded that they correspond to two different tectonic events. The N–S set (oldest) and the E–W set (younger) are present in the southern and central sector...