Die Geologie der Berge Zwischen dem Guadalhorce und dem Campo de Gibraltar (Südspanien)

Lateral variations of pressure-temperature evolution in non-cylindrical orogens and 3-D subduction dynamics: the Betic-Rif Cordillera example

“…The Ronda peridotite is distributed in several sub-massifs, the largest of them in the Sierra Bermeja. The mantle rocks are systematically associated with lower crustal units where HT-LP conditions in the field of anatexy are observed along the contact (Dürr, 1963;Loomis, 1975;Westerhof, 1977;Lundeen, 1978;Tubía and Cuevas, 1986;Tubía et al, 1997;Platt et al, 2003aPlatt et al, , 2003bMazzoli et al, 2013;Acosta-Vigil et al, 2014;Barich et al, 2014;Barich, 2016). The Jubrique Unit is one of such units; it shows a strong downward gradient of maximum temperature from Permo-Triassic phyllites and sandstones at the top, to granulites and kinzigites at the bottom of the sequence (Loomis, 1972a(Loomis, , 1972bTorres-Roldán, 1979;Balanyá et al, 1997;Negro et al, 2006) (Fig.…”

“…However, the nature of the juxtaposed rocks in contact changes abruptly along strike. In the southwest, the peridotite is overlain by the Jubrique Unit, while in the northeast the peridotite lies with a steep contact next to the Nieves Unit (Dürr, 1963;Balanyá et al, 1997;Mazzoli and Martin-Algarra, 2011;Mazzoli et al, 2013), also referred in the literature as the Dorsale Calcaire (Fallot, 1937;Durand Delga and Foucault, 1967;Kornprobst and Durand-Delga, 1985;Chalouan et al, 2008). A detailed study of the latter contact shows that the orientation of stretching lineations and fold axes in the ductilely deformed marbles and recrystallized limestones and dolostones of the Nieves Unit are all parallel to the trace of the contact (Bessière, 2019) and not perpendicular as previously published (Mazzoli and Martin-Algarra, 2011;Mazzoli et al, 2013) (Fig.…”

“…The top of Jubrique Unit shows Permo-Triassic phyllites, absent in Nieves Unit, and locally Triassic marbles, but the whole sequence is highly thinned and attenuated by late extensional faults (del Olmo Sanz et al, 1987;Balanyá et al, 1997). The Jubrique marbles then correspond to the lowermost part of the Triassic sequence (Dürr, 1963), highly attenuated by extension, which remained attached to the basement below a decollement, and the Nieves Unit the upper part of the Jubrique cover. The overall geometry can be described as a mantle core complex (Brun et al, 2018) similar to oceanic core complexes observed along slow mid-oceanic ridges with a downward-concave normal fault (MacLeod et al, 2009).…”

“…However, the original paleogeographic situations before thrusting of the Nieves and Blanca Units are strikingly different, even more with the rest of the Alpujárride units. The Nieves Unit (Dorsale Calcaire) is sometimes considered as the former cover of the Malaguide Complex (Dürr, 1963;Martín-Algarra et al, 2004;Michard et al, 2002) or of the Sebtide Complex (Chalouan and Michard, 2004). In the hyperextension interpretation of Bessière (2019) (Fig.…”