Pilar Clariana

• PhD
• Researcher at Instituto Geológico y Minero de España

La zona de estudio, en las inmediaciones de La Seu d’Urgell (Zona Axial pirenaica), está constituida por una serie estratigráfica de rocas Cambro-Ordovícicas, en su mayoría detríticas, donde la discordancia Sarda se identifica claramente entre la Serie de Jujols y la Fm. Conglomerados de la Rabassa. Las principales estructuras son pliegues N-S de p...

La relación cristalización–deformación y el estudio microestructural de las rocas metasedimentarias del macizo de la Pallaresa y de la zona de contacto con los domos gneísicos del Aston y del Hospitalet, han permitido identificar dos episodios metamórficos (AT-BP) y caracterizar su relación con los eventos de deformación producidos durante la Oroge...

The major goal of this work is to provide an insight into the structural anatomy of the Pyrenees based on the magnetic data from the Earth Magnetic Anomaly Grid 2-arc-minute resolution (EMAG2v2). We focused on providing qualitative and semi-quantitative evidence on the magnetic signature of the Pyrenees Mountain Range domains and structures. The in...

Triassic evaporites represent the regional décollement of the Pyrenees and form two salt provinces north and south of the South Pyrenean Central Salient (SPCS). We present an updated Bouguer and residual Bouguer anomaly map built upon the homogenization of available gravity data of the SPCS together with four new and representative cross‐sections,...

New geochronological (U-Pb ID‑TIMS), geochemical and isotopic data from Upper Ordovician felsic volcanic rocks recorded in the Pyrenees and Mouthoumet massifs, SW Europe, suggest that this volcanic activity is more widely represented than previously accepted, and allows a better refinement of the age span involved in the Sardic unconformity. This S...

La cartografía geológica y el estudio estructural de los sinclinales de Tor-Casamanya y Llavorsí, parte central de la Zona Axial Pirenaica han permitido encontrar estructuras y foliaciones relacionadas con dos eventos de deformación producidos durante la orogenia Varisca, D1 caracterizado por pliegues de dirección E-O a SE-NO, vergentes al Norte y...

The Paleozoic pre-Carboniferous rocks of the San Rafael Block, located to the east of the Los Reyunos Gondwanan Thrust, show Chanic structures (Late Devonian–early Carboniferous) with east vergence, which were generated in the absence of metamorphism. This Paleozoic succession is unconformably located on the basement of Cuyania. The rocks, located...

The so-called Henkel's plot (1976) allows relating density and magnetic susceptibility of rocks. In this work we focused on three paramagnetic Pyrenean granites from the Mont Louis-Andorra, Maladeta and Marimanha granitic plutons. In total, 128 sites with 310 density measurements and > 2600 susceptibility readings cover the main range of variabilit...

The Pyrenees constitutes an exceptional example of an Alpine orogenic belt characterized by basement thrust sheets involving Paleozoic rocks and Mesozoic and Cenozoic cover units detached on the Triassic evaporites, the main décollement level. This work is located in the Central Pyrenees, where gravity data help to better constrain the internal arc...

The acquisition and interpretation of gravity and magnetic data represents a cost-effective tool in geophysics since it allows to determine the geometry and distribution of the density and magnetic properties at depth of the subsurface rocks. The study area, where gravity and magnetic data have been interpreted, is the La Cerdanya basin (Eastern Py...

One of the main challenges facing geological storage is to identify cost-effective methodological workflows for characterizing and monitoring geological storage sites. In the framework of the ALGECO2 project, led by the IGME (Geological and Mining Institute, Spain), a preliminary study of the Lopín site in the NE of Spain indicated conditions were...

In this work we establish reliable correlations between density and magnetic susceptibility in three paramagnetic granites from the Pyrenees. In total, 128 sites (310 density measurements and >2600 susceptibility ones) were studied in the Mont Louis-Andorra, Maladeta and Marimanha granitic plutons covering the main range of variability of magnetic...

A new gravity survey (1164 gravity stations and 180 samples for density analysis) combined with two new geological cross sections has been carried out in a sector of the Central Pyrenees in order to improve the characterization of basement and cover architecture. From North to South, the study area comprises the southern half of the Axial Zone and...

In this work, we present new Bouguer and residual Bouguer anomaly maps of the Central Pyrenees calculated from 3590 stations, of which 1141 are new observations acquired from surveys performed between 2018 and 2019. The most prominent feature of the Bouguer anomaly is the long wavelength elongated minimum in its central part that continues to the W...

Las relaciones geométricas y cinemáticas entre las unidades de basamento de los Pirineos Suroccidentales, específicamente entre la terminación de la Zona Axial y el afloramiento de los Macizos Vascos, son desconocidas y potencialmente muy complejas (Oliva-Urcia, 2018). La gravimetría se ha aplicado con éxito en otras regiones pirenaicas para resolv...

A short video (8 min) allows, on the one hand, to spread information and on the other hand to determine its educational purpose of the Pyrenean geology. The script is based on a dialogue between the Posets Mountain and a geologist who is sampling for studying its deformation. Concepts about geological time and paleogeographic reconstructions (Scote...

Magnetic fabric analyses are a fast and non-destructive method used to determine the fabric in rocks, since the first studies of magnetic fabric, a parallelism between the magnetic fabric and the rock fabric was observed. The mineral distribution in rocks is modified by stress. Magnetic fabric analyses in relation with deformation in folded rocks c...

The characterization of the basement architecture of the Pyrenean Axial Zone, backbone of the chain, is crucial to understand its geodynamic evolution and the interplay between tectonism and magmatism. In this work, a new gravity-constrained cross section was built along the Central Pyrenees, between two of the largest Pyrenean Late Variscan granit...

The GeoPiri3D project aims to characterize the geometry and kinematics of the Permo-Carboniferous batholiths of the Central Pyrenees through a combination of potential fields and structural data. During 2018 we have acquired 824 new gravity stations and 186 rock samples. The gravity data were processed and integrated into the IGME database and a ne...

Geophysical surveying (both gravity and magnetic) is of great help in 3D modeling of granitic bodies at depth. As in any potential-field geophysics study, petrophysical data (density [r], magnetic susceptibility [k] and remanence) are of key importance to reduce the uncertainty during the modeling of rock volumes. Several works have already demonst...

The Variscan deformation in the Iberian Massif is related to the large-scale plate tectonic scenario that drove to the destruction of the Rheic and other intervening oceans, to finally form the Pangea Supercontinent. The Northern Iberian Massif structure consists in an East-vergent orogenic wedge developed at the footwall of a rootless oceanic sutu...

The Variscan deformation in the Iberian Massif is related to the large-scale plate tectonic scenario that drove to the destruction of the Rheic and other intervening oceans, to finally form the Pangea Supercontinent. The Northern Iberian Massif structure consists in an East-vergent orogenic wedge developed at the footwall of a rootless oceanic sutu...

In the frame of the GEOPIRI3D Project (financed by the Spanish Ministry of Science, Innovation and University), two new gravity-constrained cross sections have been made. The goal of this study is to analyze the Axial Zone of the central part of the Pyrenees to better constrain the geometry of the basement host rocks and genesis of the Late Varisca...

Late Ordovician magmatism is well-represented in all massifs of the Eastern Pyrenees and the Catalan Coastal Ranges but has not been reported in the central parts of the Pyrenean Axial Zone. This work shows the first geochronological evidence for Late Ordovician magmatism in the Pallaresa massif. This massif is a large E–W trending antiformal struc...

During the late Neoproterozoic and Paleozoic times, the Southern Andes of Argentina and Chile (21º-55º S) formed part of the southwestern margin of Gondwana. During this period of time, a set of continental fragments of variable extent and allochtony was successively accreted to that margin, resulting in six Paleozoic orogenies of different tempora...

The Late Ordovician magmatism is well represented in all massifs of the Eastern Pyrenees and the Catalan Coastal Ranges, which contain Upper Ordovician rocks. Nevertheless, data about this magmatic episode in the Central Pyrenees are scarce. This work shows the first geochronological data for Upper Ordovician magmatism in the Pallaresa massif. This...

During the late Neoproterozoic and Paleozoic, the Argentinean-Chilean Andes and, since the late Paleozoic, the Antarctic Peninsula formed part of the southwestern margin of Gondwana. During this long period of the geological time, a set of continetal fragments of variable size and allochtonie was successively accreted to that margin. This process,...

During the late Neoproterozoic and Paleozoic times, the Argentinean-Chilean Andes and, since the late Paleozoic, the Antarctic Peninsula, were forming part of the southwestern margin of Gondwana. During this period of time, a set of continetal fragments of variable extension and allochtonie was successively accreted to that margin, resulting in the...

Resumen: La sucesión pre-carbonífera del Complejo Guarguaraz consta de tres unidades metamórficas que se encuentran deformadas por estructuras pertenecientes a tres episodios de deformación chánicos. El primer episodio (D1) está representado por pliegues de pequeño tamaño, acostados y vergentes al NO, a los que se asocia un clivaje (S1) desarrollad...

Abstract: The structural study allowed us to recognize three main variscan deformation events (D1, D2 and D3) in the paleozoic succession in the northwest of Andorra. In the metamorphic units studied E-W trending, recumbent to inclined north vergent folds (D1) are dominant. A flat foliation (S1) is associated with these folds. As regards the no met...

Resumen: En el basamento paleozoico pre-carbonífero del Bloque San Rafael, las rocas situadas al este del Cabalgamiento Gondwánico de Los Reyunos muestran estructuras chánicas (pre-carboníferas) vergentes al este y generadas en ausencia de metamorfismo, mientras las situadas al oeste de dicho accidente fueron deformadas en condiciones metamórficas...

A new sequence of Variscan deformations is proposed for the Palaeozoic rocks of the Central Pyrenees. The non-metamorphic units include south-directed thrust systems and related folds with a poorly developed cleavage. In the metamorphic units north-verging, recumbent to inclined folds (D1), associated with a subhorizontal to south dipping cleavage,...

We propose a new sequence of Variscan deformations for the Palaeozoic rocks of the Central Pyrenees. In the nonmetamorphic structural units, south-directed thrust systems and related folds with a poorly developed cleavage are the most conspicuous structures. In the metamorphic structural units early north-verging, recumbent to inclined folds (D1),...

found associated with it. The D2 event is characterized by E-W trending and north-verging recumbent folds with an associated foliation (S2) that can be observed at all scales. The S2 foliation has a horizontal orientation, and is the main foliation in the northern and central parts of the study area. The D3 deformation event is distinguished by dev...

Two vertical different structural domains have been recognized traditionally in the Axial zone of the Pyrenees: i) infrastructure: a deep seated domain with medium to high metamorphic grade and main flat-lying foliation and ii) suprastructure: a shallow domain with lower metamorphic grade and main steep foliation. Different and contradictory interp...

The Pallaresa massif and Hospitalet dome are large E-W trend variscan structures, located in the Axial zone of the central Pyrenees. Both structures are developed in Cambro-Ordovician metasedimentary rocks. Two vertical different structural domains have been recognized traditionally in the Axial zone of the Pyrenees: i) infrastructure, seated deep...

The Tor-Casamanya Synclinorium is made up of silurian and devonian rocks. Every devonian formations, except Fonchanina Fm., of the Sierra Negra subfacies area are recognized in this syncline. The cartographie of this unit has allowed us to observe the Civis Fm. outcropping in the synclinorium central area and the Castanesa Fm. outcropping in whole...

The Llavorsi syncline is made up of Devonian and Silurian rocks. This unit has a structure, which is consequence of Hercinian polyphase deformation with thrusts, folds and tectonic foliation. The most recents studies of Llavorsi syncline reveals that the main foliation of ESE-WNW trending, is associated to tight folds whose axis are dispersed, not...

The Llavorsí syncline is made up of devonian and silurian rocks. This unit has a structure, which is consecuence of a hercinian polifasic deformation with thrusts, folds and tectonic foliation. The most recents studies of Llavorsi syncline reveals that the main foliation of ESE- WNW trending, is associated to tight folds whose axis are dispersed, n...

The Upper Ordovician sedimentary record of the western Orri dome (central Pyrenees), shows a thin succession including a thinning upwards sequence of matrix supported conglomerates in the lower part (Rabassa Fm.), fine-grained sandy and silty slates (Cava Fm.), two or three shoaling upward sequences of crinoidal limestones (Estana Fm.) and finally...