P. Schmoldt, PhD - MTNet - DIAS

7.3. Tajo Basin and central Spain
Fig. 7.13.: Geologic timescale with most relevant geologic events of the Tajo Basin
the deeper crust, resulting in elevated topography. The contact between the SCS and the
sediments of the Tajo Basin to the south is a NE-SW trending reverse fault with a throw of
more than 2 km, active from Palaeogene into Middle Miocene times [Alonso-Zarza et al.,
2002].
To the west of the Tajo Basin, accounting for the majority of the western region of
the Iberian Peninsula, the Iberian Massif crops out, constituting the oldest part of the
European Variscan orogeny formed during the Middle Devonian – Early Permian times
as consequence of the collision between Laurentia and Gondwana [e.g Colmenero et al.,
2002; Gibbons and Moreno, 2002a]. The Iberian Massif was above sea level during pre-
Cenozoic times and had a planar and low relief [Stapel, 1999], but was subsequently
deformed by various Cenozoic tectonic events resulting in an arcuate geometry [e.g.
Andeweg, 2002; Colmenero et al., 2002; Gibbons and Moreno, 2002a, and references
within]. The Iberian Massif consists mainly of igneous and metamorphic rocks and has
commonly been divided into six zones or domains with the Precambrian outcrops of the
Central-Iberian zone bordering the Tajo Basin to the west and south-west as well as to the
north-west as part of the SCS [Colmenero et al., 2002; Tejero and Ruiz, 2002; Valladares
et al., 2002] (Fig. 7.1).
Location and shape of the interface between the Jurassic – Triassic rocks forming the
Iberian Range and the Variscan rocks of the Iberian Massif below the Tajo is presently
unclear, but since the Altomira Range is part of the Iberian Range the interface is most
likely to be found to its west, below the Madrid Basin. Hence, crustal materials beneath
the northern part of the PICASSO Phase I profile, located in the Loranca Basin and the
Manchega Plain are presumably of Mesozoic times.
Investigations of neotectonic stress tensors in the SCS and Madrid Basin [de Vicente
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