Styles tectoniques de l'unite de l'Aljibe au nord du detroit de Gibraltar (Espagne meridionale)

Abstract

Different tectonic styles are recognized within the Aljibe unit N of the Strait of Gibraltar [southern Spain]. The lithology of this unit and that of the basement are, to a large extent, the cause. An anticline of the Penibetic basement, against which the sandstone of the Numidian facies has accumulated in tight folds and shingle blocks, seems to have played a large role during the emplacement of the unit. Elsewhere, it [the Aljibe unit] was dislocated into separate layers which have been overturned, welded, or overthrust. The westward displacements have local N-S components.

Late Oligocene‐Miocene syn‐/‐late‐orogenic successions in Western and Central Mediterranean Chains from the Betic Cordillera to the Southern Apennines*

“…More than likely this is the reason why different ages have been , ----as unconformable and in places as conformable, known in the literature as "grhs micacees brun tabac" (Vila, 1980) and "formations gr6so-micacbes du Nummulitique 11" (Raoult, 1974), dated Oligocene. Actually, 'Nummulitique 1I'-type terrains entirely resemble the lithotypes of the Mauretanian Units of Beni Ider and Algeciras , outcropping in the Betic-Rifian Arc (Didon, 1969;Didon et al, 1973), and those of the Sicilide Units of the Southern Apennine and of the Sicilian Maghrebides, which are characterized by typical syn-orogenic flysch deposits.…”

The age of the foredeep sedimentation in the Betic–Rifian Mauretanian Units: A major constraint for the reconstruction of the tectonic evolution of the Gibraltar Arc

“…Des unite ´s provenant du BFM sont pince ´es, me ˆme dans la pile de nappes de la cordille `re Be ´tique. Elles affleurent amplement dans la partie occidentale de la chaı ˆne, en particulier dans le Campo de Gibraltar [13][14][15], et elles se continuent en affleurements plus ou moins isole ´s jusqu'a la province de Murcie. Un bassin dont l'e ´volution tectono-se ´dimentaire est tout a `fait semblable a `celle du BFM a e ´te ´reconnu dans l'Apennin me ´ridional (oce ´an Lucanien) et est conside ´re ´comme la continuation vers le nord-est du BFM [1,25].…”

“…In the Betic Cordillera, the Mauretanian Units are represented by the Los Nogales Nappe [13], consisting only of Lower Cretaceous rocks, and -tectonically below that one -by the Algeciras Nappe, made up of Upper Cretaceous-Lower Miocene formations.…”

“…The upper part of the Colorı ´n Fm. has been attributed to the Oligocene owing to the presence of Lepidocyclina-rich beds [13], but Upper Oligocene-Lower Miocene nannofossils have been recently recognized [16]. However, an Aquitanian age was demonstrated, using planktonic foraminifera, for the uppermost levels in some outcrops of the Corredor de Colmenar [30].…”

“…The Maghrebian Flysch Basin (MFB) represents a major palaeogeographic domain involved in the building of the Maghrebian Chain [5,15,18,34], and its terrains widely crop out from the Rif to the eastern Sicily. Terrains deposited in the MFB are also present in the nappe pile of the Betic Cordillera, in particular in the Campo de Gibraltar [13][14][15]; eastward, they have been recognized in some outcrops scattered along the contact between the Internal and External Zones, from the Corredor de Colmenar, north of Malaga, up to the Ve ´lez Rubio area, in the Murcia Province [30].…”