Somoza et al. 2012). In contrast, fluids accumulate as reservoirs in near surface
sediments and create cold-seep features through fluidification and liquefaction of the
unconsolidated sediments; the formation of these structures may also be favoured by
the erosion of contourite drifts and sea-level changes (Somoza et al. 2012).
Most of the tectonic deformation of the seafloor has been located in areas of the
continental slope or basin, while the tectonic deformation of the continental shelf has
been located mostly in the area of the Al-Hoceima Bay. This is consequence first by
the source of the tectonic activity which proceeds from the boundaries of the
indentation block described by Estrada et al. (2018), where the western limits, the
Al-Idrissi Fault, would end up towards the Al-Hoceima area. A second argument
must be taken into account, it is the low magnitude of the convergence velocity of
Africa-Eurasia convergence (DeMets et al. 2015) that is being accommodated by
these structures, so that on the continental shelf the evidences of this deformation can
be obliterated by the erosive processes in moments of lowstand level or by deposits
related to the last high stand-level episode. In any case, a detailed analysis of the
possible tectonic seafloor deformation must still be carried out in areas of the
continental shelf.
6.6.2 The Key Role of Alboran Sea Seafloor Morphology
in Characterising Sediment Dynamics
The Alboran Sea represents the dumping area for sediments coming from the Betic
and Rif mountain belts (Fig. 6.1a). The way sediment has been transported and
deposited, at least in recent times, is mainly reflected by the morphosedimentary
features that characterise the present-day morphology of the Iberian and North
African continental margins and the adjacent deep basins (Figs. 6.5 and 6.6a).
Their mapping on the seafloor does not imply present-day activity, although they
have been, at least, recently active from a geological point of view. The distribution
and lateral relationships between these features reveal that each physiographic
province is dominated by a cluster of morphosedimentary features that, based on
formation processes, indicate at least two main, different sedimentary environments
on the continental margins. These two major environments are: (1) the proximal
margin defined by the continental shelf; and (2) the distal continental margin,
clustering to the continental slope, base of slope, and adjacent basins.
6.6.2.1 Sediment Dynamics on the Proximal Continental Margin
The proximal continental margin of the Alboran Sea is dominated by coastal and
fluvio-marine sedimentary processes. The seafloor morphology of the Alboran
continental shelf attests to the influence of these processes in different sedimentary
environments, including prodeltas, IPWs, bedforms, and relict nearshore sheets
(Fig. 6.4).
6 Seafloor Morphology and Processes in the Alboran Sea
187
sediments and create cold-seep features through fluidification and liquefaction of the
unconsolidated sediments; the formation of these structures may also be favoured by
the erosion of contourite drifts and sea-level changes (Somoza et al. 2012).
Most of the tectonic deformation of the seafloor has been located in areas of the
continental slope or basin, while the tectonic deformation of the continental shelf has
been located mostly in the area of the Al-Hoceima Bay. This is consequence first by
the source of the tectonic activity which proceeds from the boundaries of the
indentation block described by Estrada et al. (2018), where the western limits, the
Al-Idrissi Fault, would end up towards the Al-Hoceima area. A second argument
must be taken into account, it is the low magnitude of the convergence velocity of
Africa-Eurasia convergence (DeMets et al. 2015) that is being accommodated by
these structures, so that on the continental shelf the evidences of this deformation can
be obliterated by the erosive processes in moments of lowstand level or by deposits
related to the last high stand-level episode. In any case, a detailed analysis of the
possible tectonic seafloor deformation must still be carried out in areas of the
continental shelf.
6.6.2 The Key Role of Alboran Sea Seafloor Morphology
in Characterising Sediment Dynamics
The Alboran Sea represents the dumping area for sediments coming from the Betic
and Rif mountain belts (Fig. 6.1a). The way sediment has been transported and
deposited, at least in recent times, is mainly reflected by the morphosedimentary
features that characterise the present-day morphology of the Iberian and North
African continental margins and the adjacent deep basins (Figs. 6.5 and 6.6a).
Their mapping on the seafloor does not imply present-day activity, although they
have been, at least, recently active from a geological point of view. The distribution
and lateral relationships between these features reveal that each physiographic
province is dominated by a cluster of morphosedimentary features that, based on
formation processes, indicate at least two main, different sedimentary environments
on the continental margins. These two major environments are: (1) the proximal
margin defined by the continental shelf; and (2) the distal continental margin,
clustering to the continental slope, base of slope, and adjacent basins.
6.6.2.1 Sediment Dynamics on the Proximal Continental Margin
The proximal continental margin of the Alboran Sea is dominated by coastal and
fluvio-marine sedimentary processes. The seafloor morphology of the Alboran
continental shelf attests to the influence of these processes in different sedimentary
environments, including prodeltas, IPWs, bedforms, and relict nearshore sheets
(Fig. 6.4).
6 Seafloor Morphology and Processes in the Alboran Sea
187