Active tectonics in the Malaga Basin: evidences from morphotectonic markers (Western Betic Cordillera, Spain)

Abstract

The Malaga Basin is located in the westernmost part of the Betic Cordillera. This alpine cordillera in the south of Spain is the most active region of the Iberian Peninsula. Some of the most destructive earthquakes occurred historically in Spain took place within the Malaga Basin. In this work we focus on geomorphic and morphotectonic observations in the aim of finding active tectonic structures that could be seismogenic sources. First, we study the spatial arrangement and age of the Quaternary alluvial fan system as well as the drainage pattern of the basin, followed by the analysis of the distribution of regional markers like marine erosive surfaces and the extend of Pliocene marine deposits in the Malaga Basin. The tectonic structures inferred as active by the morphotectonic analysis are grouped into four main families: N60º-85ºE folds associated with blind thrust faults, N20º-30ºE and N40º-50ºE high angle dip-slip faults, and N165º-170ºE tear faults. Finally, their seismic potential in terms of maximum moment magnitude (Mw) is assessed by means of empirical relationships, varying between 6.0 and 7.0 depending on the hypothesis considered..Keywords: active tectonics, Malaga basin, morphotectonics, seismic potential, Western Betic Cordillera. ResumenLa cuenca de Málaga se sitúa en la parte más occidental de la cordillera Bética. En esta cordillera alpina del sur de España se han localizado algunos de los terremotos más destructivos ocurridos históricamente en la península Ibérica. En este trabajo se estudian algunos de los aspectos geomorfológicos de la cuenca del Málaga con el fin de identificar las estructuras tectónicas activas que pudiesen ser fuentes sismogénicas. Se estudia la distribución y edad del sistema de abanicos aluviales de la cuenca, así como la red de drenaje. También se analiza la distribución regional de marcadores tectónicos pliocenos, como superficies de erosión marina y ISSN (print): 1698-6180. ISSN (online): 1886-7995

Quantitative paleotopography and paleogeography around the Gibraltar Arc (South Spain) during the Messinian Salinity Crisis

“…This implies rates 4 times those previously proposed for the zone (c. 0.11 mm yr −1 ;Schoorl and Veldkamp, 2003), highlighting the prominent role of isostatic processes triggered by in mountain building around the Betic Cordillera(Silva et al, 2011). There are also evidence of Pliocene to Quaternary uplift (c. 100 m) and faulting in the study area, locally dislocating and disrupting the Tortonian and Messinian sediments(López-Garrido and Sanz de Galdeano, 1999;Schoorl and Veldkamp, 2003;Insua-Arévalo et al, 2012;Sanz de Galdeano and López-Garrido, 2012), and also in a minor extent early Pliocene (Zanclean) deposits in the Málaga-Nerja area(Guerra-Merchán et al, 2004.Apparent tectonic anomalies arise from the Discrete Anomalies model covering the same time span (Fig. 12B).…”

Development of Quaternary travertines in the carbonate mountains of the western Costa del Sol, Málaga, southern Spain

“…In the lower areas of the Sierra de Mijas, the slope is usually gentler due to the presence of remains of early Pliocene abrasion platforms (Rodríguez-Vidal et al, 2007; Insua-Arévalo, 2008). Up to three generations of Quaternary alluvial fans are present in the foothills of the Sierra de Mijas at different elevations (Insua-Arévalo et al, 2007, 2012; Guerra-Merchán et al, 2018) as well as multiple travertine buildups with different thicknesses and extents (Durán, 1996; Durán et al, 1988). These alluvial fans and travertine deposits result in a stepped landscape in the lower part of the Sierra de Mijas and along its boundaries.…”