Fault interpretation in seismic reflection data: an experiment analyzing the impact of conceptual model anchoring and vertical exaggeration

[EN]This paper presents an analysis on the limitations and advantages that some types of seismic data display present on the interpretation of the dataset

Lithospheric image of the Central Iberian Zone(Iberian Massif) using global-phase seismic interferometry

This paper presents the lithospheric structure of Central Iberia on the basis of seismic interferometry of teleseismic dat

Is it possible to retrieve Moho reflections from high-frequency autocorrelations of ambient noise?

[EN]This presentation describes the process to retrieve Moho reflections from autocorrelation of seismic noise dat

Seismic imaging and modelling of the lithosphere of SW-Iberia.

[EN]Data from a closely spaced wide-angle transect has been used to study the middle-to-lower crust and the Moho in SW-Iberia. A low-fold wide-angle stack image reveals a highly heterogeneous seismic signature at lower-crustal levels changing laterally along the profile. The lower crust features an irregular distribution of the reflectivity that can be explained by a heterogeneous distribution of physical properties. The Moho discontinuity also features a high variability in its seismic character that correlates with the different tectonic terranes in the area. A 2D finite difference code was used for solving the elastic wave equation and to provide synthetic wide-angle shots. Relatively simple layer cake model derived from conventional refraction interpretation generates the main events of the shot records. However, these models cannot account for the lateral variability of the seismic signature. In order to obtain more realistic simulations, the velocity model was modified introducing stochastic lensing at different levels within the crust. The Moho was modelled as a 3 km thick layered structure. The resulting average velocity models include a high velocity layer at mid-crustal depth, a highly reflective lower crust and a relatively thin horizontal Moho. This heterogeneous model can be achieved by lensing within the crust, a layered mafic intrusion and a strongly laminated lower crust and Moho

Characterization of the Eastern Galicia Magnetic Anomaly. A warning regarding the interpretation of aeromagnetic data

[EN]Caution should be applied to the interpretation of aeromagnetic data since often they use unknown geological bodies of unknown characteristics to explain the anomalies. A case study in the Lugo Sanabria Extensional Dome (NW Spain) shows that what was interpreted as an anomaly sourced by a basic/ultrabasic magnetic body from the lower crust/mantle, seems to be related to magnetization along extensional detachments in relation to the orogenic evolution of a thickenend Variscan crust

Imaging the lithospheric structure of the Central Iberian Zone

[EN]This presentation includes an image of the structure of the crust and upper mantle in the Central Iberian Zone and across the Central Syste

Magnetic Anomalies in Extensional Detachments: The Xistral Tectonic Window of the Lugo Dome (NW Spain)

[EN]Magnetic anomalies in the Lugo gneiss dome of the NW Iberian Massif are related with outcropping late Variscan extensional detachments The sources of magnetic anomalies are high‐grade metamorphic rocks, including migmatites and inhomogeneous granites The Lugo Dome is one of a series that coincides with a broad, curved magnetic anomaly that delineates an orocline in NW Iberi

Magnetic anomalies associated to extensional detachments? An example at Xistral TectonicWindow of the Lugo Dome (NW Spain)

[EN]Magnetic anomalies in the Lugo gneiss dome of the NW Iberian Massif are related with outcropping late Variscan extensional detachments The sources of magnetic anomalies are high‐grade metamorphic rocks, including migmatites and inhomogeneous granites The Lugo Dome is one of a series that coincides with a broad, curved magnetic anomaly that delineates an orocline in NW Iberi

Geodinámica de las cordilleras del Alto y Medio Atlas : síntesis de los conocimientos actuales

Se presenta una síntesis geodinámica de las cadenas de intraplaca del Alto y Medio Atlas de Marruecos. Estas cadenas derivan de la inversión tectónica de cuencas extensionales Jurásicas, con un acortamiento orogénico modesto (máximo del 24% en el Alto Atlas y del 10% en el Medio Atlas) heterogéneamente distribuido en el tiempo y en el espacio. Las relaciones entre tectónica y sedimentación en el margen sur del Alto Atlas indican que la deformación compresiva tuvo lugar entre el Eoceno medio y el Cuaternario. Consecuentemente con los valores de acortamiento, el espesor de la corteza detectado por gravimetría no supera los 40 km. A pesar de ello, la topografía de las cadenas del Atlas es elevada, y el modelado de campos potenciales sugiere que está causada por un marcado adelgazamiento litosférico, independiente de la tectónica compresiva regional. Un abundante magmatismo alcalino indica que el adelgazamiento litosférico coexistió con el acortamiento en los últimos 15 Ma, aunque los indicadores geomorfológicos sugieren que la mayor parte del levantamiento de origen mantélico es relativamente reciente (últimos 5 Ma). La termocronología indica que la cantidad de erosión es generalmente pequeña en el Atlas, registrándose de manera notable solo en los últimos 20-25 Ma

Caracterización conjunta del basamento en Hontomín (España) empleando datos sísmicos y microgravimétricos

9ª Asamblea Hispano Portuguesa de Geodesia y Geofísica: Madrid 28-30 de junio 2016 / Organizado por la Comisión Española de Geodesia y Geofísica ; Secçao Portuguesa das Unios Internacionais Astronomica e Geodésica ; Universidad Complutense de MadridInstitut de Ciéncies de la Terra Jaume Almera, EspañaDepartment of Geology and Petroleum Geology, University of Aberdeen, Reino UnidoDepartamento de Geología, Universidad de Salamanca, EspañaInstituto Geológico y Minero de España, EspañaPeer reviewe