Neotectonic modeling of the Ibero‐Maghrebian region

Abstract

Thin‐shell finite element techniques have been applied to model the neotectonics of the Ibero‐Maghrebian region, in the westernmost Mediterranean. This region is characterized by a complex seismotectonic pattern and moderate seismic activity associated with the convergence between Africa and Eurasia. We compare two end‐member models using different fault networks. Model predictions, including anelastic strain rates, vertically integrated stresses and velocity fields, are compared to the seismicity map and to data on directions of maximum horizontal compression. Best results are obtained assuming a low fault friction coefficient (0.05) and when the Betics and Rif are modeled as parts of the same arc‐shaped chain. The highest predicted fault slip rates are in the Tell mountains. Farther to the west, fault slip is more homogeneously distributed over the Betic‐Rif chain, Gulf of Cadiz, and Alboran Sea, indicating a diffuse geometry of the plate boundary in this area. The areas of highest predicted strain rates coincide with the most seismically active regions, located in northern Algeria and northeastern Morocco. Our best model also reproduces a major change of the stress regime, from thrusting in the east (Tell mountains) to predominantly strike‐slip and normal faulting in the west (Betic‐Rif chain and Alboran Sea). The Alboran basin is shown to be undergoing significant internal transpression and therefore cannot be considered as a rigid microplate. The western part of the Alboran Sea and surrounding areas are being extruded to the WNW with respect to Iberia.

Neotectonic modelling of the western part of the Africa–Eurasia plate boundary: from the Mid-Atlantic ridge to Algeria

“…Two recent studies have investigated the neotectonics of the Africa^Eurasia plate boundary between the eastern end of the Terceira ridge and the Gibraltar Arc [9] and in the Ibero^Ma-ghrebian region (southern part of the Iberian Peninsula and northwestern Africa) [10]. In the present modelling we integrate results from these studies concerning the geometry of the plate Fig.…”

The volcanism-related multistage hydrothermal system of El Jaroso (SE Spain): Implications for the exploration of Mars

“…Regarding the tectonics of this area (Sanz de Galdeano, 1990;Negredo et al, 2002;Colomina et al, 1998), it seems to be accepted that strike-slip and reverse fault systems have been active under the present day tectonic regime since the late Miocene. In general terms, NNE-SSW trending faults have been functioning as sinistral strike-slip faults, whereas E-W trending faults have been acting as reverse faults.…”

Morfotectónica Del Segmento Cádiz-Málaga, Sur De España

“…En la clasificación morfotectónica se han utilizado, principalmente, los estudios geológicos de: Calvert et al (2000), Capote et al (2002), Galindo-Zaldívar et al (1993), Negredo et al (2002), Reicherter y Peters (2005) y Soto y Manzano (2002. Ellos permiten asegurar que Andalucía: a) tiene un desarrollo geológico desde el Precambrico (~470 Ma); b) los materiales más antiguos están en la Zona Ossa-Morena; c) sufrió plegamientos (huroniano, caledoniano, y hercinico) que modelaron la estructura al SW-NE y tuvo un largo periodo de estabilidad tectónica; d) en el Mioceno Superior-Mioceno Inferior sufrió la compresión NW-SE de la orogenia Alpina, derivando a N-S y NNW-SSE; e) hay fallas con esas direcciones; f) surge y evoluciona hasta el presente por la interacción de las placas África y Euroasiatica; g) se localiza en el Macizo Hercínico de La Meseta y la parte septentrional de las CB; h) las montañas meridionales de la CB han tenido un levantamiento general desde el Plioceno Inferior, lo que ha configurado la actual línea de costa del Mar de Alborán.…”