cGPS Record of Active Extension in Moroccan Meseta and Shortening in Atlasic Chains under the Eurasia-Nubia Convergence

Junta de Andalucia; European Regional Development Fund; grant numbers: AGORA P18-RT-3275. Programa Operativo FEDER-Andalucia 2014–2020 Project ref. 1263446; University of Jaén; CEACTEMA; grant number: POAIUJA 23/24. Junta de Andalucía (Andalusian Board); grant numbers: RNM-148, RNM-282, RNM-370. V.T.S. was supported by the FPU PhD grant (16/04038).The northwest-southeast convergence of the Eurasian and Nubian (African) plates in the western Mediterranean region propagates inside the Nubian plate and affects the Moroccan Meseta and the neighboring Atlasic belt. Five continuous Global Positioning System (cGPS) stations were installed in this area in 2009 and provide significant new data, despite a certain degree of errors (between 0.5 and 1.2 mm year−1, 95% confidence) due to slow rates. The cGPS network reveals 1 mm year−1 North/South shortening accommodated within the High Atlas Mountains, and unexpected 2 mm year−1 north-northwest/south-southeast extensional-to-transtensional tectonics within the Meseta and the Middle Atlas, which have been quantified for the first time. Moreover, the Alpine Rif Cordillera drifts towards the south-southeast against its Prerifian foreland basins and the Meseta. In this context, the geological extension foreseen in the Moroccan Meseta and Middle Atlas agrees with a crustal thinning due to the combined effect of the anomalous mantle beneath both the Meseta and Middle-High Atlasic system, from which Quaternary basalts were sourced, and the roll-back tectonics in the Rif Cordillera. Overall, the new cGPS data provide reliable support for understanding the geodynamic mechanism that built the prominent Atlasic Cordillera, and reveal the heterogeneous present-day behavior of the Eurasia-Nubia collisional boundary.Florida Polytechnic University 16/04038 FPUUniversidad de Jaén POAIUJA 23/24 UJAEuropean Regional Development Fund 1263446, AGORA P18-RT-3275 ERDFJunta de Andalucía RNM-148, RNM-282, RNM-37

Kinematics and paleostresses in the Jebha-Chrafate transcurrent fault (northern Rif, Morocco)

The Jebha-Chrafate is an ENE-WSW sinistral major transcurrent fault of the Rif Cordillera, formed during the southwestwards emplacement of the Internal Zones on the Flysch units and the External Zones. The analysis of minor structures along the Jebha area indicates the activity of top to the SW low and high angle normal faults during the tectonic wedge emplacement. In addition, most of the kinematic indicators along the transcurrent fault zone point to a reactivation as dextral fault during the recent NW-SE Eurasia-Africa convergence and a final overprinting of normal faults during the late stages of relief uplif

Reply to the comment by A. G. Jones et al. on “Deep resistivity cross section of the intraplate Atlas Mountains (NW Africa): new evidence of anomalous mantle and related Quaternary volcanism"

Scientific discussion and different points of view are a basis of the advancement of knowledge. We acknowledge the comments of Jones et al. [2012] as an opportunity to publicly discuss the structure and origin of the Atlas Mountains. Moreover, we welcome the opportunity to compare our results with those recently published by the group responsible for the comment [Ledo et al., 2011], although it is not pertinent to comment in detail on a paper published in another journal. We also wish to remark that the paper of Ledo et al. [2011] was reviewed and published during the revision period of our contribution [Anahnah et al., 2011]; therefore, they are two different approaches and data sets, measured in different sites and by different instruments for the same region, lending readers the chance to compare different interpretations. The main differences on the data sets are: the profile of Anahnah et al. [2011] compared with the profile of Ledo et al. [2011] is 170 km longer, vertical magnetic data were obtained and lower frequencies were recordedDepartamento de Geodinámica, Universidad de Granada, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaDépartement de Géologie, Université Mohammed V, MarruecosUnidad de Granada, Instituto Geológico y Minero de España, EspañaDepartament de Geodinàmica i Geofísica, Universitat de Barcelona, EspañaInstitute of Geological & Nuclear Sciences Limited, Nueva ZelandaGéosciences Montpellier, Université Montpellier, FranciaDépartement de Géologie, Université Abdelmalek Esaadi, MarruecosCentro de Geociencias, Universidad Nacional Autónoma de México, Méxic

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The Tirinesse intramountain pliocene basin and its opening mode! (internai Rif, Morocco)

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The Ghomarides nappes are overlain by late OUgocene-eariy Burdigaiian moiassic deposits. These deposits show three successive extensional stages wich are oriented: 1- NE-SW during late Oligocene. 2- NW-SE duringAquitanian. 3- ENE-WSW during the early BurdigaiianLes nappes Ghomarides du Rif interne sont recouvertes par des dépôts post-nappes d'âge oligocène supérieur-burdigaHen inférieur. Ces dépôts, à caractères moiassiques, montrent des failles normales appartenant à trois épisodes estensifs: 7- NE-SW d'âge fin-Oiigocène. 2- NW-SE d'âge Aquitanien. 3- ENE-WSW d'âge burdigalien inférieu

Kinematics and paleostresses in the Jebha-Chrafate transcurrent fault (northern Rif, Morocco)

4 páginas, 3 figuras.-- Trabajo presentado en la 38ª Sesión Científica, Teruel, 2005.The Jebha-Chrafate is an ENE-WSW sinistral major transcurrent fault of the Rif Cordillera, formed during the southwestwards emplacement of the Internal Zones on the Flysch units and the External Zones. The analysis of minor structures along the Jebha area indicates the activity of top to the SW low and high angle normal faults during the tectonic wedge emplacement. In addition, most of the kinematic indicators along the transcurrent fault zone point to a reactivation as dextral fault during the recent NW-SE Eurasia-Africa convergence and a final overprinting of normal faults during the late stages of relief uplift.Este trabajo se ha realizado gracias a la beca postdoctoral concedida al primer firmante por parte de la Agencia Española de la Cooperación Internacional (AECI) 2004-2005. El trabajo ha sido financiado por proyectos de la Consejería de Presidencia (Junta de Andalucia), AECI y BTE 2003-01699 (CICyT).Peer reviewe