P. Schmoldt, PhD - MTNet - DIAS

7. Geology of the Iberian Peninsula
MT stations:
PICASSO project (this work)
Mediterranean Sea
MAGBET project
LEGEND
Neogene sediments
External Betics
Flysch units
Internal Betics
Alpujárride
Maláguide-Dorsale
Nevado-Filábride
Profile by Pous et al. 1999
Pous et al. 1999, Martí et al. 2009
Fig. 7.2.: Location of magnetotelluric (MT) recording sites in the Betic Cordillera denoted by dots, with colours indicating the affiliation
with the respective projects. Studies by Martí et al. [2009a] and Rosell et al. [2010] include data from preceding projects; the
blue line refers to the 2D profile location of Pous et al. [1999].
since the Late Cretaceous. The Betic Cordillera exhibits two geological very distinct regions
referred to as the Internal part and the External part (Fig. 7.1). The two parts are
separated by the Flysch units, deformed deep-water sediments of Cretaceous to Miocene
age, supposedly a former sedimentary cover at the palaeomargins of the westernmost part
of the Tethys Ocean [e.g. Platt and Vissers, 1989; ILIHA DSS Group, 1993; Gibbons and
Moreno, 2002a; Tejero and Ruiz, 2002; Chalouan et al., 2006; Pedrera et al., 2006; Martí,
2007]. The Internal Betics region is composed of graphite-rich, metamorphic Palaeozoic,
and locally Triassic, rocks that initially were part of the Alboran Domain. These rocks
were stacked over southern Iberia in latest Palaeogene – Neogene times due to the opening
of the Alboran Basin and propagated further into the Iberian margin during the Miocene
epoch. The related Oligocene – Miocene faults cut and alter the previous strata of the Internal
Betics, originally containing stacked thrust sheets emplaced in pre-Mesozoic times,
resulting in a highly complex subsurface structure [e.g. Platzman, 1992; Pous et al., 1999;
Gibbons and Moreno, 2002a; Chalouan et al., 2006; Martí et al., 2009a]. The External
Betics region, on the other hand, comprises the allochthonous cover of the former Mesozoic
south-Iberian continental margin and overlying foreland sediments, consisting of a
deformed wedge of Mesozoic to Lower Miocene carbonates and marls, overthrusting the
Neogene Guadalquivir Basin [e.g. Pous et al., 1999; Martí et al., 2009a].
7.2.1. Previous geophysical studies in the region
Magnetotelluric investigation in the central region of the Betic Chain has previously been
carried out by Pous et al. [1999] and Martí et al. [2009a] and has recently been advanced
by the MAGBET project [Rosell et al., 2010] (see Fig. 7.2 for the location of the MT
recordings). During the project by Pous et al. [1999], broadband MT data were inverted
along an approximately NW-SE aligned profile, crossing the mountain chain roughly per-
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