The Westernmost Tethys Blog Geology mapping, basin analysis and 3D modeling


Tectono-sedimentary Cenozoic evolution of the El Habt and Ouezzane Tectonic Units (External Rif, Morocco)

Filed under: geodynamic evolution,Morocco — Tags: , , — messinianalicante @ 7:41 AM

An interdisciplinary study based on lithostratigraphic, biostratigraphic, petrographic and mineralogical analyses has been performed in order to stablish the Cenozoic tectono-sedimentary evolution of the El Habt and Ouezzane Tectonic Units (Intrarif Subzone, External Rif, Morocco). The reconstructed record allowed identification of the depositional architecture and related sedimentary processes of the considered units. The Cenozoic successions were bio-chronologically defined allowing, at the same time, identification of unconformities and associated stratigraphic gaps.

Stratigraphic architecture of the Cenozoic of the El Habt and Ouezzane Units. The arrangement of the studied Logs and correlation with the timetable reflects the supposed paleogeographic position from proximal to distal. In addition, depositional sequences, unconformities, gaps (erosive and depositional), sedimentary realms and tectonic phases are shown.

The presence of five unconformities allowed to define the main stratigraphic units arranged in a regressive trend: (1) lower Paleocene interval (Danian p.p.) assigned to a deep basin; (2) Eocene interval (lower Ypresian-lower Bartonian p.p.) from a deep basin to an external carbonate-siliceous platform; (3) lower Rupelian-upper Chattian p.p. interval deposited on unstable slope with turbidite channels passing upward to an external siliciclastic platform; (4) Burdigalian p.p. interval from a slope; (5) Langhian-Serravallian p.p. interval from slope to external platform realms. The petrography of the arenites and calcarenites allowed to identify supplies derived from erosion of a recycled orogen (transitional and quartzose sub-types).


Qm/F/Lt + CE ternary diagram indicating a discrimination of the sandstones’ provenance. Qm: monocrystalline quartz; F: feldspars (plagioclase and K-feldspars); Lt + CE: lithic fragments including carbonate extrabasinal clasts.


The clay-mineralogy analysis indicates an unroofing (first erosion of Cretaceous terrains followed by upper Jurassic rocks) always accomplished by erosion of Cenozoic terrains. Several tectofacies checked in some stratigraphic intervals seems to indicate the beginning of deformation of the basement generating gentle folds and first activation of blind thrusts, mainly during the Paleogene. A pre-orogenic tectonic framework is considered as risponse to the generalized tectonic inversion (from extension to compression) as frequently registered in the central-western peri-Mediterranean areas. The large volumes of reworked terrigeneous supply during the latest Oligocene-Miocene p.p. indicates the beginnigs of the syn-orogenic sedimentation (foredeep stage of the basins) controlled by active tectonics.

Cites as: Martín-Martín, M., Guerrera, F., Hlila, R., Maaté, A., Maaté, S., Tramontana, M., Serrano, F., Cañaveras, J.C., Alcalá, F.J., Paton, D., 2020. Tectono-Sedimentary Cenozoic Evolution of the El Habt and Ouezzane Tectonic Units (External Rif, Morocco). Geosciences. 2020; 10(12):487..


Sedimentary History and Palaeogeography of the Cenozoic clastic wedges of the Malaguide Complex, Internal Betic Cordillera, Southern Spain

Filed under: Betics,geodynamic evolution — Tags: , , , , , — messinianalicante @ 8:59 PM

The Cenozoic sedimentary cover of the Malaguide Complex (Internal Betic Cordillera, Spain), in the Almería and Málaga areas, consists of a suite of sedimentary successions from continental and shallow-marine to deep-marine environments. Structural and stratigraphic relations, and petrological and geochemical signatures reveal the sedimentary evolution of the Cenozoic Malaguide Complex (CMC) from pre-orogenic (Palocene-Eocene) to syn-orogenic (Oligocene-Early Miocene) stages.

Figure 1. A, Geological sketch map of the Betic Cordillera. B, Paleogeographic reconstruction of the central-western Mediterranean area showing the position of the Mesomediterranean Microplate. C, The Internal Zones of others alpine chains of the Circum-Mediterranean belts (i.e. Rif, Tell, Calabria-Peloritani and Apennine chains). Modified from Martín-Algarra (1987), Guerrera et al. (1993, 2005), Perrone et al. (2006), Critelli et al. (2008), Perri et al. (2013).

Sandstones detrital modes of the overall succession are heterogeneous testifying to a multi-source area, marked by exhumation of the Malaguide basement terranes and of the Internal Betic Zone (Alpujárride Complex) in lower position. Pre-orogenic and syn-orogenic strata consist of four main depositional sequences: the Mula Group (Paleocene), the Xiquena Group (Eocene) for the preorogenic successions; and Ciudad Granada Group (Oligocene-Aquitanian) and Viñuela Group (Burdigalian) for the synorogenic successions. Pre-orogenic strata evolve from intra-arenite to hybrid arenites to progressive increase of sandstones in abundance of detrital supply from sedimentary cover of the internal Betic units. The unroofing history of the internal Betic Units, predominantly in the Malaguide Complex, is clearly testified in strata of the synorogenic clastic units, where detrital supply is coming from the Malaguide Complex. Sedimentary lithic fragments were derived from the Mesozoic strata of the Malaguide Complex while metamorphic detritus is related to the Internal Betic Zone basement that was exhumed starting from the Oligocene. Pre-orogenic mudrocks mainly show abundance of calcite and dolomite over quartz and phyllosilicates. Syn-orogenic mudrocks, record an abrupt decrease in calcite and dolomite and an increase of phyllosilicate, quartz and feldspars mainly in the Malaga section. The geochemical signatures attest to a compositional variation of the samples from pre-to-synorogenic successions, with palaeoweathering indices showing moderate values and a weak up-section decrease. The Cenozoic Malaguide Complex played a key role in the geodynamic evolution of the Betic Cordillera, representing the key tectonic element of the western Mesomediterranean domains.


Figure 2 Mineralogical variations along the studied stratigraphic formations.

Cite as: Critelli, S., Martín-Martín, M., Capobianco, W., Perri, F., 2021. Sedimentary history and palaeogeography of the Cenozoic clastic wedges of the Malaguide Complex, Internal Betic Cordillera, southern Spain. Mar. Pet. Geol. 124, 104775.



Oligo-Miocene evolution of the Paratethyan branches

A comparison of the stratigraphic record between two different branches of the Tethys is attempted for the first time. This study concerns the main Oligocene-Miocene tectono-sedimentary events in the Cenozoic units of the Moldavidian Basin (Romanian Eastern Carpathians) and the Maghrebian Flysch Basin (Maghrebian Chain and its lateral extension in the Betic and Southern Apennine Chains). Both basins are characterized by three main general Oligo-Miocene successions (internal, mixed, and external) corresponding to three subdomains controlled by the geological evolution of opposite plate (or microplate) margins and affected by a similar tectonic evolution. The successions of the three subdomains of the two basins show very similar features regarding stratigraphic records (lithofacies and petrofacies associations, unconformities, marker-levels, age), and the space-time sediment supply diversification (i.e., immature and super-mature arenites coming from opposite margins). Furthermore, pre-, syn- and post-orogenic successions have been identified in the geological reconstructions of both basins. The tectonic control on depositional processes (i.e., a large amount of siliciclastic supply confined in restricted time ranges, widespread volcaniclastites linked to acid-intermediate penecontemporaneous volcanic activity), and the appearance of indicators of syn-sedimentary tectonic activity (turbidites, slumps, and olistostromes) result in correlable events related to deformation phases that in turn are indicative of a similar evolution. Also, the basinal evolutionary stages (i.e., beginning of terrigenous supply, thrust-top basin formation and gravitational sliding, molassic and/or intramontane sedimentary cycles), the timing of deformation phases (drifting, foredeep), and geotectonic events (from extension to compression and post-orogenic deformation) seem to be similar. All results are encompassed in an evolutionary geodynamic model considered in the context of the Africa-Europe convergence where intermediate microplates are involved. This complex framework implies a progressive reorientation of convergence direction of these microplates that occurs during similar geodynamic events leading to the closure of the western Tethys Ocean and its related late-Alpine branches. This comparative approach, if applied to similar evolutionary phases of other mountain chains, can be useful for different geological contexts of other orogenic belts, especially to check the major general geological constraints for their evolution.

Paleogeographic evolutionary sketches of thewestern Tethyan domains for Cretaceous (A), Oligocene (B), Aquitanian (C) and Langhian (D). Relationships between microplates and basins, tectonic transport, and opening and closing of basins are shown (based also on data fromGuerrera et al., 1993, 2012a, 2012b, Belayouni et al., 2009; Amadori et al., 2012; Guerrera and Martín-Martín, 2014).

Cite as: Martín-Martín, M., Guerrera, F., Miclăuș, C., and Tramontana, M. (2020): Similar Oligo-Miocene tectono-sedimentary evolution of the Paratethyan branches represented by the Moldavidian Basin and Maghrebian Flysch Basin. Sedimentary Geology 396: 105548

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