Présence de Chitinozoaires dans le passage Siluro-Dévonien de la Montagne Noire sud-orientale (Hérault,France)

The Silurian-Devonian boundary beds of the southeastern Montagne Noire contain few but well-preserved Chitinozoans. A total of 20 species have been recognized. We distinguish 4 assemblages which characterize the Upper Ludlovian, the Pridolian and the Lochkovian sediments.     

La paléoflore du Stéphanien de l'Oued zat(Haut-Atlas de Marrakech — versant nord — Maroc)

The presence of Stephanian was discovered in 1930, on the North side of High Atlas of Marrakesh, while prospecting coal. In this work, we have studied in detail the paleoflora collected in Oued Zat, and for the first time are described and pictured 18 species. The paleofloristic association of seven species leads to an upper Stephanian locality.     

Famennian (Late Devonian) ammonoids from the Ouarourout section (Saoura Valley,Algeria)

In North Africa, the ammonoids constitute an important part of the Devonian marine macro-invertebrates. New material has been recently collected in the ‘Argiles de Marhouma’ Formation from several sections located near Béni-Abbès in the Saoura Valley (Ougarta Mountains, Algerian Sahara). Red nodular limestones (i.e., ‘griotte’ facies) characterize this formation rich in ammonoids. The assemblages from the Ouarourout section are composed of Goniatitida and Clymeniida constituting 30 species and 19 genera belonging to 11 families, with Cyrtoclymenia, Erfoudites, Kosmoclymenia, Planitornoceras, Platyclymenia, and Prionoceras, as the most abundant genera. The taxonomic comparison and the biostratigraphic correlations are made by considering the assemblages recorded in the Anti-Atlas of Morocco, which are very close to those observed in Algeria. In the Ouarourout area, the ‘Argiles de Marhouma’ Formation contains middle and late Famennian ammonoid assemblages and three biostratigraphic intervals can be identified: Planitornoceras, Platyclymenia and Medioclymenia.     

Sur quelques echinodermes(Cystoides et Crinoides) de l'Ashgill d'Aragon (Espagne)

The material collected in the outcrops of Fombuenaand Luesma allows to specify the distinctive characters of the genera Corylocrinus and Caryocrinites, to describe two new species and to complete the morphology of Heliocrinites rouvillei and Proteocystites hispanica. The Crinoid association of these localities shows a very close composition with that of Coat-Carrec (Finistère). The new observations establish definitively the structure of the dorsal cup and the oral face of Mespilocystites. The occurence of the genera Stichocystis, Eucystis and Mespilocystites is recorded for the first time in Aragon. Cystoids and Crinoids confirm the existence of Ashgillian in the western part of the Armorican Massive.     

Acritarches ordoviciens des Zekkara (Maroc oriental)

Ordovician Acritarchs (Arenigian-Llanvirnian) werefound in the blacks of the Zekkara (Morocco). A well preserved assemblage proves this age, which was unknown and often indicated as Silurian or Tournaisian-Visean age. In this association, which is especially typical of the Middle Ordovician, about one hundred and twenty taxa have been recognized; some morphologic characteristics of a certain number of them are indicated here.     

Contribution palynologique à la connaissance du Triasdu Haut-Atlas de Marrakech,Maroc

This note provides a precision on the age (Carnian) of one of the terms of the High Atlas series of Marrakech by the palynological datation and gives an account on the recent palaeontological discoveries realized in course of a sedimentological study of a so called azoic series. The deposit environment is briefly sketched.     

Présence de l’éocrinoïde Ascocystites Barrande (Echinodermata,Blastozoa) dans l’Ordovicien supérieur (Caradoc) de l’Anti-Atlas (Maroc) : premières données

Family Ascocystitidae, defined and established by Georges Ubaghs in 1967, includes a single genus, Ascocystites. This genus was described and figured for the first time by Barrande in 1887, from Bohemian specimens. Thereafter, specimens brought close to Ascocystites or assigned to this genus were described starting from samples collected in Bohemia in the Armorican Massif or in Portugal. The new specimens were collected in Morocco in the Eastern Anti-Atlas, within the formation of Izzeguirene of Caradoc age. The studied material includes several sandy slabes often containing many well-preserved and almost complete individuals. These levels gather individuals of various sizes, corresponding to various stages of development. The morphological study in progress should allow a specific attribution by comparison with the Bohemian and Armorican forms actually known. The Moroccan material has, in addition, the advantage of corresponding to associations of several Echinodermata groups, rich in individuals, allowing a taphonomic and possibly paleoenvironmental study. Biostratigraphically, Ascocystitidae are actually known between Middle (Armorican Massif and Portugal) and Upper Ordovician (Bohemia and now Morocco). The discovery of Ascocystitidae in the Moroccan Anti-Atlas extends their distribution, within gondwanian domain, during Middle and Upper Ordovician.     

Caractérisation probable du Sinémurien près de Telouat (Haut-Atlas,Maroc): Datation palynologique

The liassic beds of the High-Atlas of Marrakech are rarely fossiliferous so all paleontological discoveries must be reported in order to give more biostratigraphical precisions for the interpretations of the sourcestrata basin. Palynological investigations in section composed of marl and dolomites with gypsum yield assemblages which the overall composition is characterized by the general dominance of Corollina in combination with relatively rare occurence of others nonsaccate pollen grains. Because the comparison of the associations previously described from the Lower Jurassic of Morocco and Sahara and the fact that the richness of Corollina has no stratigraphical value, the assemblages from the Telouat' section can be reasonably regarded to be indicative of a Sinemurian age.     

Biofaciès à Cuneigervillia-Pteromya et biofaciès à Eomiodon dans l'Hettangien du Quercy (Aquitaine orientale)

New research made in the Hettangian sequence in Quercy by one of us (R.C.) has led to the discovery of shell beds constituted solely of Bivalvia in two deposits in the departement of Tarn, one near Vaour, the other near Les Cabannes-de-Cordes. These Eomiodon and Cuneigervillia-Pteromya signify an environment of abnormal salinity and permit long distance correlations.     

Présence d'Eryma bedelta (Crustacea Decapoda) dans le Bajocien du Maroc oriental

The value attached to the presence in Morocco of aspecies which is essentially North-European, is increased by its recent discovery in an Iranian deposit. The stakes, in that established, have to be pointed out and reserved in order to try, in the future, to reconstruct the dispersion areas of the representatives of this genus, especially adapted to the Jurassic seas.     

Un nouveau Cycloconchide (Mollusca Bivalvia) du Llanvirn inférieur (Ordovicien) des Monts de Tolède (Espagne)

A new Cycloconchid, designated Ananterodontaoretanica, has been collected from the Lower Llanvirn (Montes de Toledo). The only known specimen is described and compared with several genera of Ordovician Cycloconchids, the validity of which is briefly discussed.     

Biostratigraphic control of the latest-Ordovician glaciogenic unconformity in Alnif (Eastern Anti-Atlas, Morocco), based on brachiopods

In the Alnif region of the Eastern Atlas (Morocco), seven fossiliferous horizons within the Lower-Ktaoua and Upper-Tiouririne formations (Ktaoua Group), as well as in the glaciomarine microconglomeratic shales of the Upper Formation of the Second-Bani Group have yielded biostratigraphically significant brachiopods and other taxa, such as trilobites and echinoderms. Several brachiopod species with short stratigraphic ranges, well-known in south-western Europe, allow a precise chronostratigraphic control of a succession that displays important lateral lithological and facies changes, when compared with the type sections in the Central Anti-Atlas. They have also permitted a better consensus between the macrofauna-determined age and that based on micropaleontological analyses. For the first time, the occurrence of a Hirnantia Fauna within the microconglomeratic shales of the Upper Formation of the Second Bani Group is reported. The biostratigraphic conclusions restrict the age of the Latest Ordovician glaciation to the early Hirnantian.     

Ammonites du Toarcien du Haut Atlas central (Maroc)

In the central High Atlas, the Toarcian Stage is represented by a marl and marly limestone series of variable thickness. Two sections have been studied: Amellago (500 m) and Aït Athmane (100 m). Ammonites from the two sections allowed to characterize the Polymorphum, Levisoni, Bifrons, Gradata, and Speciosum zones. The Polymorphum Zone provided, among others: Dactylioceras (Eodactylites) mirabile, D. (E.) pseudocommune, Dactylioceras (Orthodactylites) aff. crosbeyi and Neolioceratoides aff. hoffmanni; the Levisoni Zone provided a rich ammonite fauna composed of, Calliphylloceras nilssoni, Dactylioceras (Orthodactylites) cf. semiannulatum, Eleganticeras exaratum, Harpoceras falciferum, H. pseudoserpentinum, H. serpentinum, H. subplanatum, Hildaites cf. forte, H. levisoni, H. cf. serpentiniformis, H. cf. subserpentinus, H. striatus, H. wrighti, Lytoceras siemensi, Lytoceras sp., Maconiceras soloniacense, Phylloceras sp., Polyplectus pluricostatum et Polyplectus sp.; the Bifrons Zone provided Eleganticeras sp., Harpoceras subplanatum?, Hildoceras bifrons, H. lusitanicum, H. semipolitum, H. sublevisoni, Hildoceras sp., Porpoceras gr. vortex – verticosum; the Gradata Zone was characterized by Pseudocrassiceras bayani, P. frantzi, Pseudocrassiceras sp., Pseudocrassiceras sp. indet.; and the Speciosum Zone provided an Hammatoceras aff. insigne. These species have been described and illustrated for the first time for the central High Atlas. Most of them are common to several basins of the north Tethyan margin and the Subboreal Domain of NW Europe.     

Les assemblages de diatomées du bassin messinien de Boudinar (Maroc nord-oriental)

The Messinian is one of the strongest biogenic silica accumulation periods in the world and more particularly in the Mediterranean, where it is marked by an important diatomitic sedimentation. In the Boudinar basin (Morocco north-Eastern, Western Mediterranean), the section of Sidi Haj Youssef, localised near the volcano of Ras Tarf, has approximately 100 m thickness of clayey-marly series in which 12 diatomitic levels of variable thickness are intercalated. The microfloristic study of diatoms on 86 samples, carried out in detail for the first time, made it possible to recognize 50 genus of diatoms (24 of centric and 26 of pennate) represented by 185 species (75 species of centric and 110 species of pennate). Four hundred individuals were taken from each sample to determine the relative frequency of each taxon within the diatoms assemblages. Thus, several assemblages were defined by the predominance of the following species: Coscinodiscusmarginatus, Actinoptychussenarius, Thalassionemanitzschioides, Actinocycluscurvatulus, Thalassiothrixlongissima, Rhizosoleniastyliformis and Actinocyclusehrenbergii. These diatoms assemblages display a littoral marine environment in communication with the opened sea. The abundance of the cold water species towards the base and the top of the section suggests broad exchanges of the basin with the Atlantic Ocean in Messinian. The predominance of the species Thalassionemanitzschioides and/or Thalassiothrixlongissima indicates periods of strong productivity that can be associated to upwelling systems.     

Nouvelles recherches géologiques et malacologiques sur le Quaternaire de la province de Tarfaya (Maroc méridional)

The province of Tarfaya located in the South of Morocco and West of Anti-Atlas is a part of the wide costal basin of West Sahara. Marine Pleistocene is poorly represented: three levels only can be numbered. Moghrebian, often attributed to Pliocene, possesses a doubtless quaternary gastropoda fauna. Messaoudian (Maarifian according to G. Lecointre) is known from a single site and contains a relatively warm fauna. Recent deposits, outcropping at less than +5 meters, cannot easily been determined by means of paleontology: they are Ouljian and perhaps Harounian-Rabatian. Compared with type-sections of Casablanca, an increase of southern influences in the faunas is noted: especially the Messaoudian shells present a rather obvious tropical type.     

Patines et cortex de météorisation de grès du site rupestre d’Oum La Leg (Anti-Atlas, Maroc)

Within the framework of the European Commission's program “Patine du Desert” (DG Research; INCO-CT-FP6-2004-509100), partially concerning the preservation of Saharan engraved rock art, the approach led to the study of the sandstone patina from the rock art site of Oum La Leg (Anti-Atlas, Morocco). The rock and its Tazina school engravings are sometimes covered with a thin brown-ochre coating which only shows a dark patina, the desert patina. This film corresponds to a weathering cortex whose formation is contemporary with wet events from the Holocene period. On the surface, the patinas’ diversity is linked to the heterogeneous distribution of manganese oxides (birnessite and todorokite) due to a reorganisation which led to the incorporation of aeolian silts. Some dating suggestions are made to establish an ante quem age for the engraved lines.     

Ammonites calloviennes du Sud d'Israël:Systématique,biostratigraphie et paléobiogéographie

131 ammonites, whole or in fragments, were collectedbetween 1958 and 1977 within 150 m of the Jurassic section at Hamakhtesh Hagadol (Hathira), Negev. A detailed paleontological study allows the recognition of twenty four species ascribed to ten genera; one genus and four species being new. Their age assignment is Middle and Late Callovian. The specific character of this fauna and its relationships to other assemblages in neighbouring regions are discussed.