Cabliers Ridge and the Provençaux Bank (Fig. 5.4), and progressively shoals
southward; meanwhile the Pytheas Basin has a maximum thickness of 4 s twtt
(Gómez de la Peña et al. 2018), is bounded to the east by the E Cabliers Bank, to
the west by the W Cabliers Bank and the Trois Fourches Promontory, and to the
south by the Provençaux Bank (Figs. 5.4 and 5.10).
Finally, above the thinned continental and magmatic crust lies the EAB. It has
triangular geometry, its northern flank being controlled by the NE-SW La SerrataCarboneras fault zone and constituted by the Adra Ridge and the Cabo de Gata
Promontory; its southern flank corresponds to the NW-SE Yusuf fault zone and
progressively opens eastward in transition with the oceanic lithosphere of the
Algero-Provenzal Basin, so that its maximum thicknesses (>4.5 s twtt) would be
in the western segment (Vázquez and Vegas 1996; Booth-Rea et al. 2007) (Figs. 5.4
and 5.10).
The structural highs—the NE-SW oriented Alboran Ridge, and its prolongation
to the southwest in the Francesc Pagés and Tofiño banks—correspond to an antiform
and a volcanic alignment (Figs. 5.4, 5.6 and 5.10), although the bulk of uplift was
mainly produced by folding and inversion of its northern flank verging northwards,
during the post-Tortonian compressive phase (d’Acremont et al. 2020). The banks of
La Herradura and Djibouti Ville are probably located in relation to the NW-SE
eastern faulted boundary of the Intermediate basin and correspond to two volcanic
edifices formed in the Upper Miocene. However, their relief continues to the NE
(in a NE-SW trend) in two branches, the northern one is constituted by the José
Medialdea and Chella banks, and the southern one by the Adra Ridge, El Sabinar and
Pollux banks and the Cabo de Gata Promontory (Figs. 5.6 and 5.10). The DSDP high
displays a horseshoe geometry, its NE-SW directed northern branch taking in the
Avempace bank and the smooth high that disconnects the WAB and Motril basins,
while a central NNW-SSE branch separates the WAB of the Intermediate Basin and
a southern E-W branch includes the Ibn-Batouta Bank (Fig. 5.10). Notwithstanding,
some inversion and uplift of the northern and southern branches may have occurred
during the post-Tortonian compressive phase.
Several structural highs have been defined to the east of the Alboran Ridge on the
African margin. Two of them are the Trois Fourches Promontory and the
Porvençaux Bank, of NE-SW trend (Fig. 5.10) and marking metamorphic basement
highs (Gómez de la Peña et al. 2018). Another two are the NW and E Cabliers ridges
(Figs. 5.4 and 5.6), respectively found in the northward prolongation of the aforementioned basement highs and described as volcanic edifices (Duggen et al. 2008).
These structures were uplifted in the post-Tortonian compressive phase and produced tilting of pre-Messinian sedimentary units at least (Gómez de la Peña et al.
2018), a deformation apparently greater to the northeast, especially in relation to the
intersection of NE Cabliers Bank and the Yusuf Fault (Figs. 5.4, 5.6 and 5.10).
5 A Geological History for the Alboran Sea Region
131
southward; meanwhile the Pytheas Basin has a maximum thickness of 4 s twtt
(Gómez de la Peña et al. 2018), is bounded to the east by the E Cabliers Bank, to
the west by the W Cabliers Bank and the Trois Fourches Promontory, and to the
south by the Provençaux Bank (Figs. 5.4 and 5.10).
Finally, above the thinned continental and magmatic crust lies the EAB. It has
triangular geometry, its northern flank being controlled by the NE-SW La SerrataCarboneras fault zone and constituted by the Adra Ridge and the Cabo de Gata
Promontory; its southern flank corresponds to the NW-SE Yusuf fault zone and
progressively opens eastward in transition with the oceanic lithosphere of the
Algero-Provenzal Basin, so that its maximum thicknesses (>4.5 s twtt) would be
in the western segment (Vázquez and Vegas 1996; Booth-Rea et al. 2007) (Figs. 5.4
and 5.10).
The structural highs—the NE-SW oriented Alboran Ridge, and its prolongation
to the southwest in the Francesc Pagés and Tofiño banks—correspond to an antiform
and a volcanic alignment (Figs. 5.4, 5.6 and 5.10), although the bulk of uplift was
mainly produced by folding and inversion of its northern flank verging northwards,
during the post-Tortonian compressive phase (d’Acremont et al. 2020). The banks of
La Herradura and Djibouti Ville are probably located in relation to the NW-SE
eastern faulted boundary of the Intermediate basin and correspond to two volcanic
edifices formed in the Upper Miocene. However, their relief continues to the NE
(in a NE-SW trend) in two branches, the northern one is constituted by the José
Medialdea and Chella banks, and the southern one by the Adra Ridge, El Sabinar and
Pollux banks and the Cabo de Gata Promontory (Figs. 5.6 and 5.10). The DSDP high
displays a horseshoe geometry, its NE-SW directed northern branch taking in the
Avempace bank and the smooth high that disconnects the WAB and Motril basins,
while a central NNW-SSE branch separates the WAB of the Intermediate Basin and
a southern E-W branch includes the Ibn-Batouta Bank (Fig. 5.10). Notwithstanding,
some inversion and uplift of the northern and southern branches may have occurred
during the post-Tortonian compressive phase.
Several structural highs have been defined to the east of the Alboran Ridge on the
African margin. Two of them are the Trois Fourches Promontory and the
Porvençaux Bank, of NE-SW trend (Fig. 5.10) and marking metamorphic basement
highs (Gómez de la Peña et al. 2018). Another two are the NW and E Cabliers ridges
(Figs. 5.4 and 5.6), respectively found in the northward prolongation of the aforementioned basement highs and described as volcanic edifices (Duggen et al. 2008).
These structures were uplifted in the post-Tortonian compressive phase and produced tilting of pre-Messinian sedimentary units at least (Gómez de la Peña et al.
2018), a deformation apparently greater to the northeast, especially in relation to the
intersection of NE Cabliers Bank and the Yusuf Fault (Figs. 5.4, 5.6 and 5.10).
5 A Geological History for the Alboran Sea Region
131