Recent and active faults and folds in the central-eastern Internal Zones of the Betic Cordillera

Abstract

The most recent tectonic structures of the central-eastern Internal Zones of the Betic Cordillera (from 3.1ºW to 1.7ºW and to the south of 37.525ºN) include fault and folds developed from the Late Miocene onwards, which are related to N-S/NW-SE directed continental collision and moderate thickening of a crust that is relatively hot at depth. In this setting, E-W to WSW-ENE folds, with locally associated E-W transpressive right-lateral and reverse faults, favoured the emersion of the northern Alborán basin palaeomargin and the progressive intramontane basin disconnection. The NNE-SSW to NE-SW trending regional left-lateral Palomares and Carboneras fault zones are dominant structures in the easternmost part of the cordillera. In addition, NW-SE to WNW-ESE trending normal and oblique-slip normal faults are widespread. The collision is still active and continues to drive active folds and faults, some probably being the likely source of moderate-sized earthquakes. The Campo de Dalías and surrounding sectors, deformed by active ENE-WSW folds and NW-SE to WNW-ESE oblique-slip normal faults, are probably the sites with the largest FRQFHQWUDWLRQ RI VLJQL¿FDQW HDUWKTXDNHV GXULQJ UHFHQW \HDUV 0RGHUDWHPDJQLWXGH HDUWKTXDNHV 0Z WR KDYH RFFXUUHG WKHUH at fairly regular intervals, in 1804, 1910, and 1994. Toward the east, NW-SE trending normal faults extending from Almería to the Tabernas basin deform the Quaternary rocks with associated moderate seismicity (the 2002 Gergal Mw 4.7 earthquake, and possibly the 1894 Nacimiento earthquake, felt with intensity VII). In the Sorbas-Vera basin, the Palomares fault zone is also responsible for moderate-sized earthquakes (1518 Vera earthquake). In the Almanzora corridor, NW-SE to WNW-ESE trending Lúcar-Somontín faults also could be considered one of the possible source of moderate-magnitude seismicity (1932 Lúcar, Mw 4.8 earthquake felt ISSN (print): 1698-6180. ISSN (online): 1886

Compressional tectonic inversion of the Algero-Balearic basin: Latemost Miocene to present oblique convergence at the Palomares margin (Western Mediterranean)

“…The continent to ocean transition between the Alboran and Algero-Balearic basins at the Palomares margin does not show the typical passive margin basement morphology with tilted blocks that have been recognized at nonvolcanic passive margins like the western Iberian one [e.g., Reston et al, 2007] or at the , 2012;Giaconia et al, 2012aGiaconia et al, , 2012bPedrera et al, 2012;Giaconia et al, 2013]. The set of structures is consistent with the present stress field and fits in an oblique convergence model where a NW-SE trending shortening affects the NNE-SSW oriented Palomares margin.…”

“…Main tectonic structures associated to the late Miocene (post latemost Tortonian) to present‐day compressional tectonic inversion of the Betics, Rif, Alboran, and Algero‐Balearic basins, both onshore and offshore. The fault traces and kinematic data are taken from previous authors [ Martínez‐Díaz et al , ; Booth‐Rea et al , , ; Masana et al , ; Booth‐Rea et al , ; Marín‐Lechado et al , ; Masana et al , ; Domzig et al , ; Gràcia et al , ; Pedrera et al , ; Moreno et al , ; Pedrera et al , ; Sanz de Galdeano et al , ; Gràcia et al , ; Alfaro et al , ; Pedrera et al , ; Perea et al , ; Sanz de Galdeano et al , ; Giaconia et al , ; Maillard and Mauffret , ; Martínez‐García et al , ; d'Acremont et al , ]. AbF, Abubacer fault; AlF, Al‐Idrisi fault; AMF, Alhama de Murcia fault; ARF, Alboran Ridge fault, BFS, Baza basin fault system, BSFZ, Bajo Segura fault zone; CFZ, Carboneras fault zone; GrFS, Granada basin fault system; GuFS, Guadix basin fault system; PFZ, Palomares fault zone; PoFZ, Polopos fault zone; TFZ; Terreros fault zone; XB, Xauen bank; YF, Yusuf fault.…”

“…Tectonics 10.1002/2015TC003861 Figure 2. Structural map where the main tectonic structures active during the Quaternary are shown: the Albox fault (AF), the Alhama de Murcia fault (AMF), the Carboneras fault zone (CFZ), the Palomares fault zone (PFZ), the Polopos fault zone (PoFZ), and the Terreros fault zone (TFZ) (see Figure 1 for location) [Booth-Rea et al, 2004a, 2004bMasana et al, 2004;Marín-Lechado et al, 2005;Masana et al, 2005;Gràcia et al, 2006;Pedrera et al, 2006Pedrera et al, , 2009Sanz de Galdeano et al, 2010;Booth-Rea et al, 2012;Giaconia et al, 2012aGiaconia et al, , 2012bPedrera et al, 2012;Giaconia et al, 2013]. Furthermore, focal mechanisms, local stress tensors (from both focal mechanisms and fault slickenline inversion data) [Stich et al, 2003;Fernández-Ibáñez et al, 2007;Giaconia et al, 2013], and GPS geodetic data [Echeverria et al, 2013] are shown.…”

Structure of Alluvial Valleys from 3-D Gravity Inversion: The Low Andarax Valley (Almería, Spain) Test Case

“…10 shows they run on a horizontal profile obtained by inversion with the general GROWTH inversion method. Alignments following the NW -SE faults can be seen in these sections, according to the NNW -SSE normal faults shown by some authors (Sanz de Galdeano et al 2010;Pedrera et al, 2012). This N 140-160 E direction also coincides with old faults that occurred during the Miocene period (Martínez-Martínez and Azañón, 1997).…”

Deformation style and controlling geodynamic processes at the eastern Guadalquivir foreland basin (Southern Spain)

“…Therefore, an important piece of the Iberian margin became part of the upper Alborán plate, hindering the ongoing subduction of the Iberian margin and promoting the transmission of collision‐related compressional stresses into the foreland since middle Miocene time. In the overriding Alborán plate, mechanical coupling caused the formation of crustal‐scale open folds, NNE‐SSW to NE‐SW left‐lateral fault mostly deforming the easternmost Betic Cordillera, and high‐dipping NW‐SE normal faults restricted to the uppermost crust and broadly distributed [e.g., Pedrera et al ., , , ]. Compressional stresses were also transmitted into the eastern part of the lower plate inducing the formation of reverse faults and related monoclines along the forebulge of the Guadalquivir Basin.…”