Abstract The Khabt-el-Hajar Formation, very rich in bryozoans and echinoderms but relatively poor in other fossil groups, has provided a brachiopod association that allows an improvement in the stratigraphic correlation of this Moroccan eastern Anti-Atlas unit with those from the Upper Ordovician of SW Europe and the rest of the Anti-Atlas. The intermediate marly beds, with bryozoan and echinoderm patches, of the Khabt-el-Hajar Formation have yielded Streptis ? sp., Paucicrura catalanica and Drabovia sp. Of these, P. catalanica , the richest in the association and known up to now exclusively from the Catalonian Coastal Ranges in NE Spain, is dated as mid to late Katian (Ka2–Ka4), since it occurs in the La Mora Slates, correlatable with horizons of that age from Iberia, Sardinia or the Montagne Noire. The analysis of the stratigraphic and palaeobiogeographical ranges of the bryozoans from the same formation agrees with the correlation above. The quartzitic sandstones that underlie the Khabt-el-Hajar Formation in the surroundings of Erfoud have yielded a different brachiopod association, including Kiaeromena ? chouberti and Rostricellula termieri among other forms more poorly represented. K. ? chouberti allows its yielding horizon to be dated as mid Katian (Ka2) and supports the identification of the sandstone-dominated unit where it occurs as the Tiouririne Formation.

Abstract A variety of unrelated organisms produce agglutinated tubes as dwelling structures, and the habit has persisted since the Neoproterozoic. Onuphionella , an agglutinated tube composed of mica flakes, has been found in lower Cambrian strata on several palaeocontinents. In this paper, a new species of the genus, Onuphionella corusca sp. nov., is described from the Sandbian (Upper Ordovician) First Bani Group of the Erfoud region, Morocco. The First Bani Group was formed in a storm-dominated shelf environment below fair-weather wave base. The agglutinated tubes are found in abundance on numerous bedding surfaces, possibly representing repeated colonization between storm events, and the tube maker must have been a major part of the local ecosystem. This is the first report of Onuphionella from Ordovician rocks and the first from Gondwana. Supplementary material: Data tables for major oxide and trace element results are available at https://doi.org/10.6084/m9.figshare.c.4283612

Abstract This paper presents the results of an extensive chemical and isotopic investigation on natural thermal and cold fluids (spring waters and associated gases) discharging throughout the main geological domains of Morocco. The chemical features of the thermal springs are mainly dependent on rock dissolution involving Triassic evaporite formations, producing either Na–Cl or Ca–S0 4 composition, although mixing with shallower connate high-saline waters in Neogene post-orogenic sedimentary layers cannot be ruled out. Only in the Moroccan Meseta and Anti-Atlas domains have spring discharges probably undergone equilibration as a result of water-rock interaction in granites. Of the chemical and isotopic features of the gas seeps, 3 He/ 4 He ratios and δ 13 C–C0 2 values indicate the occurrence of a significant contribution of mantle-derived gas, especially at Oulmès (Moroccan Meseta) and Tinejdad-Erfoud (Anti -Atlas), where associated waters are found to equilibrate at relatively high temperatures (c. 130 °C). These areas are also characterized by the presence of Pliocene to Quaternary basaltic volcanic rocks. Thermal discharges located along the Rif front and related to the NE–SW-oriented main strike-slip faults are associated with a CH 4 - and/or N 2 -rich gas phase, derived respectively from a crustal or an atmospheric source. Some of them have significant contents of 3 He that could indicate the rising of mantle fluids. Such a striking isotopic signature, which is not related to any recent volcanism visible at surface, is likely to be associated with cooling magma at depth related to transpressive fault systems. Similarly, in the northeastern area, the small, although significant, enrichment of 3 He in the gas discharges seeping out along the Nekor seismic active fault and related to Pliocene-Quaternary basalts also suggests a deep-seated (magmatic) contribution. The distribution of thermal discharges is strongly related to the main active tectonic structures of Morocco. Moreover, this study indicates the presence of deep active tectonic structures in areas until now considered as stable. In particular, the NE–SW-trending Nekor fault may be part of a major system that extends to the Moroccan Meseta and into the Smaala–Oulmés fault system, thus emerging as a deep structure with crustal significance.

Abstract The fossil trade of Paleozoic material from southern Morocco was estimated by some North American media to reach about US$ 40 million a year, and it supplies fossil shows and shops all over the world. In its initial stages of extraction, preparation and export, this trade constitutes the main source of income to more than 50 000 people in an area basically conscribed within the triangle made by Alnif–Erfoud–Taouz (eastern Anti-Atlas), and generated a true ‘fossil industry’. This includes diggers and miners, artisans that prepare and restore fossils (and others dedicated to making replicas with decorative purposes), quarries working on fossiliferous ornamental rocks, and numerous middlemen and Moroccan wholesalers who annually attend the large fossil fairs of Europe and the USA. More than 25 years of intensive exploitation of fossil resources in the Anti-Atlas has also produced important scientific discoveries, such as world-renowned fossil biotas like Fezouata and Tafilalt, and hundreds of new Paleozoic fossil taxa, in parallel with a worrying destruction of outcrops and many palaeontological sites. The new mining legislation also deals with the extraction, collection and trade of geological specimens, and a future specific legal framework for fossils and geological heritage will try to manage the existing industry. It will aim to restrain the constant deterioration of the rich Moroccan geological heritage, while enabling strategies of sustainable development so that the local population is not negatively affected.

Abstract The majority of Upper Ordovician bryozoan occurrences in Morocco are known from the Anti-Atlas. These faunas are abundant and diverse; however, many of them still remain unstudied. The few explored bryozoan faunas of the Katian age exhibit high abundance and diversity of erect branched and massive trepostomes accompanied by few esthonioporines, cryptostomes and fenestrates, whereas cystoporate bryozoans are not known here. They occupied various biotopes within inner- and outer-ramp settings. Bryozoan faunas from the Upper Ordovician of Morocco are rather related to faunas from other parts of the Mediterranean Province (France, Carnic Alps, Sardinia) containing few species of Laurentian and Baltic origin. Trepostome bryozoans from Moroccan occurrences often display signs of gigantism explained by undisturbed growth in cold and quiet environmental conditions.

Abstract Storm-dominated siliciclastic shelf deposits in the upper half of the Upper Tiouririne Formation (Upper Ordovician, upper Berounian– c. Katian 1–2) of southern Morocco contain large specimens of at least two species of Archaeoconularia ( A . aff. consobrina and A . cf. imperialis ). Pseudoconularia cf. grandissima occurs in basal beds of the formation, but is far less abundant than Archaeoconularia . The large size of the Archaeoconularia (>500 mm long in some cases) suggests gigantism induced by cold, nutrient-rich waters. Specimens preserving the apical end terminate in a schott, indicating that the conulariids were severed near the apex prior to final burial. Many of the Archaeoconularia occur in monospecific aggregations in which the component specimens exhibit preferential alignment, probably owing to entrainment and burial by storm currents or flows. Some Archaeoconularia are encrusted by edrioasteroids and/or craniid brachiopods, which in certain cases are so closely spaced as to interfere with growth. The edrioasteroids and brachiopods were probably epibionts attached to living, erect or semi-erect conulariids that were partially infaunal. More generally, Late Ordovician conulariid assemblages of South Polar Gondwana and adjacent terranes exhibit low generic diversity relative to those of low- to mid-latitude terranes (Baltica and Laurentia), and are dominated numerically by Archaeoconularia .