P. Schmoldt, PhD - MTNet - DIAS

7.1. Overview
Geology of the Iberian Peninsula
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The Iberian Peninsula is the westernmost extent of the Eurasian Continent, bordered by
the Bay of Biscay to the north, the Atlantic Ocean to the west, the Mediterranean Sea
to the south and southeast, and connected to the test of the Eurasian plate in the northeast
(Fig. 7.1). Its most prominent topographic features are the Cantabrian Mountain
Chain in the northwest, the Pyrenees in the northeast, the Betic Mountain Chain in the
south, as well as the intraplate ranges Spanish Central System and Iberian Ranges. Thorough
descriptions of the Iberian Peninsula geology are given for example in Gibbons and
Moreno [2002b, and references within] and Moratti and Chalouan [2006, and references
within]. A detailed overview about the geological evolution as well as past and presentday
stress fields of the Iberian Peninsula are given in Andeweg [2002]; a compilation of
figures therein, related to the PICASSO Phase I investigation, is given in Section A.1 in
the appendix. A general summary of the events most relevant for the PICASSO Phase I
investigation is given in the following paragraphs, focussing on the regions in the vicinity
of the PICASSO Phase I profile. Therefore, this Chapter deals mostly with the tectonic
settings of the Betic Cordillera and the Tajo Basin, including its subbasins and surrounding
regions. But at first a general overview is given in the following paragraphs describing
the main tectonic features of the Iberian Peninsula.
Due to the distinct geological contrast between the eastern and western Iberian Peninsula
these two parts are commonly referred to as Alpine Spain and Variscan Spain (sometimes
also referred to as Hercynian Spain), respectively. The former is dominated by
Mesozoic and Cenozoic sediments and young belts, whereas the latter comprises Precambrian
and Palaeozoic rocks with minimal overprint by Alpine deformation [e.g. Gibbons
and Moreno, 2002a]. The Variscan belt results from oblique collision and interaction between
the Palaeozoic supercontinents Gondwana, Laurentia, and Baltica and a number
of continental microplates taken place during Neoproterozoic through Palaeozoic times
[Abalos et al., 2002]. The Iberian Massif, accounting for the majority of the Variscan
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