Rabat, Morocco
Rabat, Morocco

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Aquit M.,University of Kiel | Kuhnt W.,University of Kiel | Holbourn A.,University of Kiel | Chellai E.H.,Cadi Ayyad University | And 3 more authors.
Cretaceous Research | Year: 2013

Lithological evidence, benthic foraminiferal census counts, and X-ray fluorescence (XRF) scanner-derived elemental data were integrated with planktonic foraminiferal biostratigraphy and bulk carbonate stable isotopes to retrace the Turonian to early Campanian paleoenvironmental evolution and sea-level history of the Tarfaya Atlantic coastal basin (SW Morocco). The lower Turonian is characterized by laminated organic-rich deposits, which contain impoverished benthic foraminiferal assemblages, reflecting impingement of the oxygen minimum zone on the shelf during a sea-level highstand. This highstand level is correlated to the global transgressive pulse above the sequence boundary Tu1. The appearance of low-oxygen tolerant benthic foraminiferal assemblages dominated by Gavelinella sp. in the middle to upper Turonian indicates an improvement in bottom water oxygenation, probably linked to offshore retraction of the oxygen minimum zone during a regressive phase. This interval is marked by major regressive events expressed by a series of erosional truncations associated with the prominent sequence boundaries Tu3 and/or Tu4. Dysoxic-anoxic conditions recorded in the upper Santonian of the Tarfaya Basin coincide with the eustatic sea-level rise prior to Sa3 sequence boundary. The lower Campanian transgression, only recorded in the southern part of the Tarfaya Basin, coincided with substantial deepening, enhanced accumulation of fine-grained clay-rich hemipelagic sediments and improved oxygenation at the seafloor (highest diversity and abundance of benthic foraminiferal assemblages). Stable isotope data from bulk carbonates are tentatively correlated to the English Chalk carbon isotope reference curve, in particular the Hitch Wood Event in the upper Turonian, the Navigation Event in the lower Coniacian, the Horseshoe Bay Event in the Santonian and the Santonian/Campanian Boundary Event. © 2013 Elsevier Ltd.


Wenke A.,University of Heidelberg | Zuhlke R.,University of Heidelberg | Boutib L.,ONHYM | Jabour H.,ONHYM | And 2 more authors.
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 | Year: 2010

Although sufficiently mature source rocks (Early Jurassic, Late Cretaceous) and suitable reservoir facies (e.g. Late Jurassic, Early-Middle Tertiary) exist in the Tarfaya Basin (TB), past exploration has yielded few oil/gas shows but no commercially producing wells. In order to better understand the HC system of the TB, an integrated basin analysis approach has been applied including numerical modeling of the source and sink areas. Key methodologies include sequence stratigraphy, thermochronology, biostratigraphy, source-to-sink analysis, geochemistry and basin modeling. The current sequence stratigraphic interpretation is based on i) well correlation, ii) seismo-/sequence stratigraphic interpretation; iii) data from outcrop analogue. The Mesozoic to Early Cenozoic basin development includes 5 major basin stages i) Permian to Pliensbachian rift- and sag, ii) Toarcian to Cenomanian drift, iii) Turonian to Early Eocene drift with initial Atlasian deformation, iv) Middle-Late Eocene drift with major Atlasian compression; v) Late Eocene to Early Miocene drift with major Atlasian uplift and inversion. This contribution focuses on sequence stratigraphy and numerical modeling in the sink area. At least 51 3rd order sequences have been identified along a key transect in the Jurassic-recent basin fill. © 2010, European Association of Geoscientists and Engineers.


Le Roy P.,CNRS Oceanic Domains Laboratory | Sahabi M.,Laboratoire Geosciences Marines | Maad N.,Laboratoire Geosciences Marines | Rabineau M.,CNRS Oceanic Domains Laboratory | And 8 more authors.
Marine and Petroleum Geology | Year: 2014

This study focuses on the evolution of the Atlantic NW Moroccan Rharb continental shelf during the Neogene and Quaternary. This region is part of a foreland basin bounded by the Rif mountain belt and thus provides an interesting geological setting to study the interactions between eustasy and tectonics and the driving mechanisms controlling stratigraphic patterns. The results are supported by an interpretation of new data including high-resolution seismic lines coupled with an interpretation of industrial seismic lines and detailed logs of industrial wells completed by micropaleontologic analysis of cuttings. The stratigraphy reveals a succession of three mega sequences related to the transition from an underfilled to an overfilled stage reflecting the long-term evolution of the foreland system. Moreover, evidence of cyclical sea-level changes are visible in the upper megasequence composed of three depositional sequences assumed to be fourth-order sequences generated in response to the most recent 100-ka glacio-eustatic cycles. This study also shows the peripheral deformation of the Rharb shelf responsible for changes in the geometry of the deposits and thicknesses of the sedimentary fill during the Pliocene and Pleistocene. The most important change was triggered by the uplift of the Lallah Zahra Ridge corresponding to a major Quaternary kinematic boundary and the broad uplift of the southern shelf interpreted as a flexural uplift of the forebulge domain. The deformation-controlled sediment dispersal pattern consists of a progressive growth of the shelf accompanied with a progressive shift of depocenters from the North East to the South West and a general progradation to the North West along the southern border. This progressive filling has led to the confinement of the Rharb paleo-valley across the continental shelf. The complete filling of the palaeo-valley was followed by the development of a more than 70-m thick prodeltaic lobe at the front of the Oued Sebou river mouth during the Holocene. © 2013 Elsevier Ltd.


Capella W.,University Utrecht | Matenco L.,University Utrecht | Dmitrieva E.,Repsol | Roest W.M.J.,University Utrecht | And 5 more authors.
Tectonophysics | Year: 2016

Tectonic processes in the Gibraltar region are associated with Africa-Iberia convergence and the formation of the Betic-Rif orogenic system. The Late Miocene shortening recorded in the Rif orogen resulted in gradual shallowing and eventual closure of the Rifian Corridor, a narrow marine gateway connecting the Atlantic Ocean with the Mediterranean Sea. This closure is associated with paleoenvironmental changes that ultimately led to the Mediterranean Messinian Salinity Crisis. Here we present a structural analysis based on a combination of field kinematic data and interpretation of reflection seismic lines acquired for petroleum exploration to understand the deformational phases associated with the closure of the Rifian Corridor. We show the succession of three Late Miocene to present day events, an initial thin-skinned nappe thrusting, followed by regional subsidence and continued by thick-skinned contraction. The transition from in sequence thin-skinned tectonics during subduction to thick-skinned contraction during continental collision resulted in significant acceleration of tectonic uplift and associated exhumation. This is related to a change in the regional deformation linked to plate convergence, but possibly also coupled with deep lithospheric or dynamic topography processes. Such a mechanism is also common for other Mediterranean orogens during late stages of slab retreat, where accelerated tectonics resulted in rapid sedimentation and associated basins evolution. We conclude that the thick-skinned contraction in the Rif orogeny initiated in the late Tortonian, has created a cumulative uplift in the order of 1. km, and provided high enough uplift rates to close the Rifian Corridor. © 2016 Elsevier B.V.


Maad N.,European University of Brittany | Maad N.,CNRS Oceanic Domains Laboratory | Maad N.,Laboratoire geosciences marines | Le Roy P.,European University of Brittany | And 11 more authors.
Comptes Rendus - Geoscience | Year: 2010

A recent high resolution seismic survey was carried out along the North-West Moroccan Atlantic continental shelf to perform sequence stratigraphy and to better understand the link between the onshore observations across the western termination of the Rif front and the multibeam bathymetric data previously collected across the Gulf of Cadiz. Seismic interpretation clearly shows evidence of deformation affecting the Pleistocene sedimentary cover. This is mainly located between the Lalla Zahra ridge and the Neogene nappes that outcrop at the seabed to the North of Larache, where the identified structures bound the upper part of a gravitationally spreading lobe and are interpreted to be developed by activation of the major tectonic structures located at the southern front of the Rif Cordillera. The offshore extension of the Lalla Zahra Ridge is characterised by an east-west trending major folded and faulted corridor. This structure marks the active front of Prerifan area and corresponds to a major Quaternary kinematic boundary in the western prolongation of the ENE-WSW trending Jebha fault. © 2010 Académie des sciences.


Tari G.,OMV Austria Exploration and Production GmbH | Jabour H.,ONHYM
Geological Society Special Publication | Year: 2013

The Moroccan salt basin appears to be very unique in the sense that it is not sedimentary loading but tectonic inversion which appears to drive the latest stages of salt-related deformation in the central part of the basin. The gravity potential to maintain salt tectonics is provided by the differential uplift of the Atlas Mountains, located adjacent and striking almost perpendicular to the margin. Along the offshore part of the Moroccan salt basin there are many play types, most of them related to the Triassic syn-rift salt. Toe-thrust anticlines at the basinwards edge of the salt basin form very large structures. Traps associated with salt tongues and diapirs define a more 'classical' salt-flank play. Numerous salt tongues, sheets and canopy complexes provide for a 'Gulf of Mexico-style' subsalt play. Despite the numerous untested play types, there have been only four deep-water exploration wells drilled in the entire Moroccan salt basin, none of them having subsalt penetrations. © The Geological Society of London 2013.


Ali S.,University of Kiel | Stattegger K.,University of Kiel | Garbe-Schonberg D.,University of Kiel | Kuhnt W.,University of Kiel | And 2 more authors.
International Journal of Earth Sciences | Year: 2014

The petrography, heavy mineral analysis, major element geochemical compositions and mineral chemistry of Early Cretaceous to Miocene-Pliocene rocks, and recent sediments of the Tarfaya basin, SW Morocco, have been studied to reveal their depositional tectonic setting, weathering history, and provenance. Bulk sediment compositional and mineral chemical data suggest that these rocks were derived from heterogeneous sources in the Reguibat Shield (West African Craton) including the Mauritanides and the western Anti-Atlas, which likely form the basement in this area. The Early Cretaceous sandstones are subarkosic in composition, while the Miocene-Pliocene sandstones and the recent sediments from Wadis are generally carbonate-rich feldspathic or lithic arenites, which is also reflected in their major element geochemical compositions. The studied samples are characterized by moderate SiO2 contents and variable abundances of Al2O3, K2O, Na2O, and ferromagnesian elements. Binary tectonic discrimination diagrams demonstrate that most samples can be characterized as passive continental marginal deposits. Al2O3/Na2O ratios indicate more intense chemical weathering during the Early Cretaceous and a variable intensity of weathering during the Late Cretaceous, Early Eocene, Oligocene-Early Miocene, Miocene-Pliocene and recent times. Moreover, weathered marls of the Late Cretaceous and Miocene-Pliocene horizons also exhibit relatively low but variable intensity of chemical weathering. Our results indicate that siliciclastics of the Early Cretaceous were primarily derived from the Reguibat Shield and the Mauritanides, in the SW of the basin, whereas those of the Miocene-Pliocene had varying sources that probably included western Anti-Atlas (NE part of the basin) in addition to the Reguibat Shield and the Mauritanides. © 2013 Springer-Verlag Berlin Heidelberg.


Sachse V.F.,RWTH Aachen | Littke R.,RWTH Aachen | Kluth O.,RWE AG | Schober J.,RWE AG | And 3 more authors.
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 | Year: 2010

The Tarfaya Basin is bounded by the Anti-Atlas, the Reguibat High / Tindouf Basin and the Mauretanides and developed since the opening of the Atlantic in the Permian to Triassic with continental extension. Little is known about source rock potential in Tarfaya Basin, excluding Cenomanian/Turonian black shales which were investigated e.g. by Kolonic et al. (1) and Kuhnt et al. (2). In general Lower Silurian, Upper Devonian, Lower Jurassic, Lower Cretaceous, Albian, Cenomanian shales as well as Lower Tertiary shales are considered as source rocks. To get more information about their potential, outcrop samples covering various stratigraphic units of the Tarfaya Basin, the Bas Draa area and the northwestern Tindouf Basin were collected. TOC/TC-measurements, sulphur measurements, Rock- Eval pyrolysis, vitrinite reflectance measurements, fluorescence microscopy and organic-geochemical analyses were carried out on these samples to get basic information on their thermal maturity, the potential to generate hydrocarbons and their depositional environment. © 2010, European Association of Geoscientists and Engineers.

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