LES ROCHES MAGMATIQUES ET PYROCLASTIQUES DU CONGLOMERAT STRUNIEN DE L'OUED TIFLET (MESETA NORD OCCIDENTALE MAROCAINE): PETROGRAPHIE, GEOCHIMIE ET PROVENANCE

In the north boundary of the Sidi Bettache basin (northwestern morrocan Meseta), the strunian period is characterized by coarse detrital sedimentation, among them the limestone conglomerate of Tiflet river. This conglomerate is rich in magmatic pebbles varying by nature and shape. Petrographical and geochemical studies allow distinguishing eleven facies, which generally correspond to basic, including gabbros, intermediate or acids rocks. Tuffs, sulfides bearing-rocks and oxides are also identified. Age of this magmatic rocks is discussed

Geodiversity Examples of Morocco: From Inventory to Regional Geotourism Development

The soil and subsoil of Morocco are rich in geological phenomena that bear the imprint of a history which goes back in time more than 2000 million years. Very many geologically remarkable sites exposed in accessible outcrops, with good quality remained unknown to the general public and therefore deserved to be vulgarized. It is a memory to acquaint the present generations but also to preserve for future generations. In total, a rich geological heritage in many ways: Varied land- scapes, international stratotypes, various geological structures, varied rocks, mineral associations, a huge procession offossiles, remnants of oceanic crust (ophiolites) among oldests ones in the world (800 my), etc. For this geological heritage, an approach of an overall inventory is needed, both regionally and nationally, taking into account all the skills of the earth sciences. This will put the item on the natural (geological) potentialities as a lever for sustainable regional development. For this, it is necessary to implement a strategy of “geoconservation” for the preservation and as- sessment of the geological heritage. A website “lithothèque du Maroc” is under construction.info:eu-repo/semantics/publishedVersio

LES ROCHES MAGMATIQUES ET PYROCLASTIQUES DU CONGLOMERAT STRUNIEN DE L'OUED TIFLET (MESETA NORD OCCIDENTALE MAROCAINE): PETROGRAPHIE, GEOCHIMIE ET PROVENANCE

In the north boundary of the Sidi Bettache basin (northwestern morrocan Meseta), the strunian period is characterized by coarse detrital sedimentation, among them the limestone conglomerate of Tiflet river. This conglomerate is rich in magmatic pebbles varying by nature and shape. Petrographical and geochemical studies allow distinguishing eleven facies, which generally correspond to basic, including gabbros, intermediate or acids rocks. Tuffs, sulfides bearing-rocks and oxides are also identified. Age of this magmatic rocks is discussed

Systematics of detrital zircon U–Pb ages from Cambrian–Lower Devonian rocks of northern Morocco with implications for the northern Gondwanan passive margin

This study was found by the Ministerio de Economia y Competitividad (MINECO) of Spain through the project PANGEATOR (CGL2015-71692) and the Pre-Doctoral scholarship BES-2016-078168. We are indebted to Mike Hall and Brad McDonald for their assistance and technical support on sample preparation and the LA-ICPMS, respectively. The CL imaging was carried out on the Curtin University's Microscopy & Microanalysis Facility, whose instrumentation has been partially funded by the University, State and Commonwealth Governments, and the Scanning Electron Microscope (SEM) Facility at the University of Edinburgh. Analysis in the SHRIMP and GeoHistory Facilities, JdLC, Curtin University were enabled by AuScope (auscope.org.au) and the Australian Government via the National Collaborative Research Infrastructure Strategy (NCRIS) and an Australian Geophysical Observing System grant provided to AuScope Pty Ltd. by the AQ44 Australian Education Investment Fund program, respectively. The NPII multi-collector was obtained via funding from the Australian Research Council LIEF program (LE150100013). The SIMS analyses were performed at the NERC Ion Microprobe Facility of the University of Edinburgh (UK). Comments from two anonymous reviewers and editorial handling by Prof. Victoria Pease are acknowledged. Funding for open access charge: YUniversidad de Granada / CBUA.The systematic acquisition of U–Pb geochronological data from detrital zircon grains has become an essential tool in tectonic studies focused on reconstructing the pre–Variscan geography of the northern Gondwanan passive margin. New detrital zircon ages for 16 samples from the Cambrian–Lower Devonian succession of the Moroccan Mesetas (northern Morocco) are reported here. The results, combined with previously published data, reassert the strong West African Craton affinity of the Paleozoic sedimentary rocks, characterized by dominant Cadomian/Pan–African (c. 850–540 Ma) and Eburnean (c. 2.2–1.9 Ga) detrital zircon populations and a minor Leonian/Liberian (c. 2.5 Ga) population. Primary sources of these zircon grains are well established as the West African Craton located just to the south, but also in the Precambrian basement that locally crops out in the Moroccan Mesetas themselves. During the Cambrian–Early Ordovician, erosion preferentially dismantled Cadomian (c. 590–540 Ma) arc–derived rocks of the Gondwanan continental margin, while later, the slightly older Pan–African (c. 650–600 Ma) basement became the main sediment source. In the studied samples, irregularly present minor detrital zircon populations suggest additional sediment provenance from secondary sources such as: (i) remote northeastern African cratons (e.g., Saharan Metacraton and/or Arabian–Nubian Shield) that likely could have provided the c. 1.1–0.9 Ga and, possibly, the c. 1.9–1.7 Ga zircon grains, and (ii) rift–related Cambrian–Early Ordovician volcanic centers in the Moroccan Mesetas that supplied heterogeneously distributed – although locally dominant in small areas – sedimentary detritus before rift abortion and burial underneath the overlying passive margin sedimentary succession.Ministerio de Economia y Competitividad (MINECO) of Spain through the project PANGEATOR CGL2015-71692Scanning Electron Microscope (SEM) Facility at the University of EdinburghAustralian Geophysical Observing System grant by AQ44 Australian Education Investment Fund programAustralian Research Council LE150100013Universidad de Granada / CBUA BES-2016-07816

Mixed and recycled detrital zircons in the Paleozoic rocks of the Eastern Moroccan Meseta: Paleogeographic inferences

Ministerio de Economía y Competividad (MINECO) of Spain through the project CGL2015-71692-P and the Pre-Doctoral scholarship BES-2016-078168. Zircon analyses and imaging were carried out on the SHRIMP II, LA-ICPMS and SEM facilities at the John de Laeter Centre, Curtin University, with the financial support of the Australian Research Council (LE150100013) and Auscope NCRIS (AQ44 Australian Education Investment Fund program)The paleogeographic evolution of the Moroccan Variscides has been a matter of discussion for several decades, with current theoriesmostly based on classical geological correlations. In this regard, the scarce number of studies devoted to U-Pb geochronological analyses of detrital zircon populations is particularly limiting when trying to ascribe the different domains to a single continental piece either derived from the West African Craton or to different sources, with some located in the Nubian Shield or the SaharanMetacraton. In thiswork, detrital zircon grains from 10 samples of sandstones from the Paleozoic (Ordovician to Devonian) sequence of the Eastern Meseta andMiddle Atlaswere dated in order to identify possible sediment sources and elucidate the paleogeography of this easternmost portion of the Moroccan Variscides. The main detrital zircon populations have Ediacaran-Cryogenian ages (610–670 Ma, related to the Cadomian and/or Pan-African orogeny) and middle Paleoproterozoic ages (1980–2080 Ma, related to the Eburnean orogeny), which are in agreement with previous data from the Western Meseta, suggesting similarity between both Mesetas, and strong West African Craton affinity. Such an affinity verifies themost accepted paleogeographic interpretation considering that theMoroccan Mesetas remained attached to northern Gondwana during the entire Paleozoic period. The main differences between our samples and those from the Western Meseta concern the minor detrital zircon populations, such as the Cambro-Ordovician and the Tonian-Stenian ones. In particular, Eastern Meseta and Middle Atlas samples lack a Cambro-Ordovician detrital zircon population, usually interpreted as related to the rifting that opened the Rheic Ocean. This population is locally reported in the Western Meseta and widely described in southwestern Europe, where magmatism of this age is well known. Furthermore, the most northeastern samples are also characterized by a Tonian-Stenian detrital zircon population (up to 30% of the data), which might imply northeastern African sources (Saharan Metacraton and/or Arabian-Nubian Shield)Ministerio de Economía y Competividad (MINECO) of Spain CGL2015-71692-P, BES-2016-078168Australian Research Council (LE150100013)Auscope NCRIS (AQ44 Australian Education Investment Fund program