Les series du Toarcien-Aalenien du SW du Moyen-Atlas (Maroc); precisions stratigraphiques et signification paleogeographique

2001 ◽  
Vol 172 (6) ◽  
pp. 723-736 ◽  
Author(s):  
Hassan El Arabi ◽  
Benali Ouahhabi ◽  
Andre Charriere

Abstract Toarcian and Aalenian deposits from south west of the Middle Atlas named "Couches du Seloum", were classically considered as a "border facies" of the Middle Atlas trough, which was extensively developed in the northern part of the folded Middle Atlas. Both studies realized on the border of the Bekrit-Timahdite syncline and the Iguer Awragh-Afennourir syncline, allow to specify the stratigraphy, the spatial distribution of deposits and to reconsider the paleogeographic organization of this "border" in the integral context of the northern Middle Atlas trough during the Toarcian and the lower Bajocian interval. A lithostratigraphic succession of the "Couches du Selloum" raised in the western part of Bekrit-Timahdite syncline shows the superposition of three units. Unit 1 is made of clay, reddish and gray marl, locally gypseous, assigned to the lower Toarcian. Unit 2 is essentially composed of a subnodular calcareous series, which consists of discontinuous, wavy and upward-thickening beds. The upper offshore is the most frequent environment. It is mainly made of crinoidal calcarenites, yielding some ammonites and brachiopods rich levels. The Middle Toarcian (Bifrons zone and Gradata zone) was identified in the lower part of this unit. Most of the upper Toarcian zones were distinguished (Speciosum zone, Meneghinii zone and Aalensis zone), they are represented in the upper part by brachiopods (Stroudithyris) and ammonites (Hammatoceras, Dumortieria and Catulloceras) rich set. On several lateral sections, the uppermost part of these pseudo nodular limestones is dated from Opalinum zone (levels with Leioceras and Tmetoceras). Unit 3 shows several facies: bioclastic calcarenites arranged in decimetrics beds, showing cross stratifications; microsparitic limestones in thick beds with silexites. The macrofauna is scarce, often represented by some crinoidal and mollusks fragments; some Zoophycos appear in the top bed of the set. The following deposits illustrate the evolution from the shoreface to the upper offshore. This unit is overlain by a sedimentary discontinuity, materialized by a boring surface, some pockets of accumulations with belemnites and a cover of ferruginous nodules. Ammonites drowned on the discontinuity surface or in the basis of the first interbedded marls which overlies this surface sign the Aalenian-Bajocian transition (top of the Concavum zone and the basis of Discites zone). Immediately above we found some index fauna of the Laeviuscula zone. The series overlaying the "Couches du Selloum" comprises thinning up alternations of limestone/marl, passing progressively to the "Marnes de Boulmane" Formation. Lateral variations and interpretations; SW to NE variations: The thickness and facies variations observed in the Bekrit-Timahdite syncline (C1 to C9), denote the existence of marine intervals generally more dilated, with some marly deposits developed towards the SW; on the contrary towards the NE, series are exclusively calcareous, reduced in thickness, and often condensed in their upper part. The same evolution is observed between the deposits of the Iguer Awragh syncline to the SW and those of Afennourir in the NE [Benshili et al., 1999]. SE to NW variations: Some observations realized in a Toarcian-Aalenian outcrop recently discovered in the sector of Outghalline (C11), shows that an uplifted area separates the marly basin of Bekrit from the Iguer Awragh one. Such variations denote a partition of the Toarcian Selloum basin, located in south west of the Middle Atlas trough, into several entities which are regrouped under the denomination of "Blocks of Selloum"; two NE-SW trending notably subsiding gutters are recognized, the Iguer Awragh-Afennourir and the Bekrit-Timahdite, separated by a shoal (ridge of Ijadrane). Paleogeographic framework of the SW border of the Middle Atlas trough: A synthesis of the geometry of the "Blocks of Selloum" and some paleogeographic and structural features of the NW border of the Middle Atlas trough, as they appear in a recent synthesis [Benshili, 1989; Elmi et al., 1989; Benshili et Elmi, 1994; Charriere, 1990; Fedan, 1993; Laadila, 1996; Sabaoui, 1998; El Arabi et al., 1999], is shown in 3 episodes from Toarcian to Aalenian. The southwestern part of the Middle Atlas studied here, does not appear in any case as a coastal area surrounding the Middle Atlas trough, but like a gulf occupied by marine deposits which is isolated from the Middle Atlas trough by the shoal areas called the "Haut-fond de Boulmane". In the Middle Atlas trough, the sequences prograde in a NE direction and show blocks tilting generally towards the same direction. On the other hand, in the "Blocks of Selloum" the tilting acts toward the SW, against the direction of the global Tethyan polarity.

Author(s):  
Alison Forrestal

This introductory chapter examines the early career of Vincent de Paul between 1581 and 1611, moving from his birth and education to his arrival in Paris in 1608, and his immersion in the dévot environment there. It begins with a summary of his birth in south-west France and his years of education to university level. It then outlines his appointment as an almoner in the royal household of Marguerite de Valois in early 1610, after he had taken up residence in Paris two years earlier. It concludes with an analysis of the other aspects of his material livelihood during these years, including his acquisition of the abbey of Saint-Léonard-de-Chaumes in western France.


1989 ◽  
Vol 2 ◽  
pp. 175-183 ◽  
Author(s):  
Daniel J. Chure

“Although I work a lot with fossils in my own research on fishes, I do not care to be called a paleontologist; and I am turned off by many aspects of the public-relations hoopla surrounding paleontology, especially dinosaurs…. One could easily argue that the schools' fascination with dinosaurs might also detract from the other aspects of earth science and biological science and, in the end, weaken paleontology's image as an activity for hard-nosed grown-ups.”K.S. Thomson, 1985: p. 73“Let dinosaurs be dinosaurs. Let the Dinosauria stand proudly alone, a Class by itself. They merit it. And let us squarely face the dinosaurness of birds and the birdness of the Dinosauria. When the Canada geese honk their way northward, we can say: “The dinosaurs are migrating, it must be spring!”R.T. Bakker, 1986: p. 462It is a now oft-repeated statement that we are in the Second Golden Age of dinosaur studies. This may at first seem to be yet another overstatement by dinosaur fanatics; in fact, it is substantiated on a number of fronts. Research activity is certainly at an all-time high, with resident dinosaur researchers on every continent (except Antarctica) and dinosaurs known from every continent (including Antarctica). This activity has resulted in a spate of discoveries, including not only new genera and species, but entirely new types of dinosaurs, such as the segnosaurs. Well-known groups are producing surprises, such as armored sauropods and sauropods bearing tail clubs. Good specimens of previously named genera are revealing unsuspected structural features that almost defy explanation, as in the skull of Oviraptor. However, dinosaur studies extend far beyond the traditional emphasis on dinosaur morphology, and encompass paleobiogeography, paleoecology, taphonomy, physiology, tracks, eggs, histology, and extinction, among others. In some cases, several of these studies can be applied to a single taxon or locality to give us a fairly detailed understanding of the paleobiology of some species.


2007 ◽  
Vol 16 (07n08) ◽  
pp. 1982-1987
Author(s):  
◽  
N. N. AJITANAND

Recent experimental investigations have focussed on the abnormal spatial distribution of away side jet fragments as signals of significant medium induced effects. A variety of theoretical models including recent string-theory based efforts have supported the notion of Mach Cone like effects in the low viscosity QGP fluid. However, the presence of significant flow fields may deflect the fragmentation direction producing a significantly differing type of jet topology from that of the Mach cone. Three particle correlation functions constitute a powerful method whereby the predominance of one or the other type of mechanism can be differentiated. In this work the use of such an approach will be demonstrated via simulations and the results of its application to RHIC data will be presented.


Antibodies ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 57 ◽  
Author(s):  
Patrícia de Sousa-Pereira ◽  
Jenny M. Woof

Immunoglobulin A (IgA) plays a key role in defending mucosal surfaces against attack by infectious microorganisms. Such sites present a major site of susceptibility due to their vast surface area and their constant exposure to ingested and inhaled material. The importance of IgA to effective immune defence is signalled by the fact that more IgA is produced than all the other immunoglobulin classes combined. Indeed, IgA is not just the most prevalent antibody class at mucosal sites, but is also present at significant concentrations in serum. The unique structural features of the IgA heavy chain allow IgA to polymerise, resulting in mainly dimeric forms, along with some higher polymers, in secretions. Both serum IgA, which is principally monomeric, and secretory forms of IgA are capable of neutralising and removing pathogens through a range of mechanisms, including triggering the IgA Fc receptor known as FcαRI or CD89 on phagocytes. The effectiveness of these elimination processes is highlighted by the fact that various pathogens have evolved mechanisms to thwart such IgA-mediated clearance. As the structure–function relationships governing the varied capabilities of this immunoglobulin class come into increasingly clear focus, and means to circumvent any inherent limitations are developed, IgA-based monoclonal antibodies are set to emerge as new and potent options in the therapeutic arena.


Perception ◽  
1996 ◽  
Vol 25 (12) ◽  
pp. 1419-1436 ◽  
Author(s):  
Paul Locher ◽  
Sharon Gray ◽  
Calvin Nodine

Two experiments were performed to examine how the subjective balance of a painting is created by its structural features and to determine if balance influences the way people look at paintings. Stimuli consisted of sixteen reproductions of twentieth-century paintings varying in artistic style and a reconstructed less-balanced version of each. Participants in experiment 1 determined the location of the balance center of each composition, assigned ‘weights’ to the pictorial features which contributed to the location of the balance center, and rated the picture for balance. It was found that design and museum professionals and individuals untrained in the visual arts were in good agreement as to the structural framework underlying the balance organization of a painting. For all participants, disruption of the balanced organizations of the original compositions led to reliable shifts in the location of the perceived balance centers of the originals compared with their less-balanced perturbations. Additionally, it was observed that particular features as such were not the origin of the balance phenomenon; rather, judgments concerning the balance structure and its center were dependent on the global integration of information across a wide area of the display field, but especially from its central region. Last, the subtle changes in balance structure between versions resulted in lower ratings of balance being assigned to the less-balanced perturbations by the design professionals only; the other two participant groups evaluated overall balance of the versions as comparable. In experiment 2, eye movements of a different group of untrained individuals were recorded as they performed similar tasks on the art stimuli. It was found that disruption of the balance structure of the original representational but not abstract compositions resulted in different regions of the original and perturbed versions being visually explored. Findings of both experiments are related to theoretical notions of balance.


2021 ◽  
Vol 1 (4) ◽  
pp. 341-346
Author(s):  
Asril Gunawan

Gambus Paser music is one among traditional perfoming arts belongs to Paser tribe. Contextually, gambus Paser performing art cannot be detacted from its socio-culural since it geographically affects the characteristic of that cultural music. Generally, the culture of Gambus Paser music has its various values according to its various geographical dispositions. Geographically varied characteristic of Gambus Paser music is reflected on the interpretation of the music especially on the style of pentengan (picking technique) and the lyric of Gambus song. Gambus Paser music is also characteristically identified by the use of that pentengan style. On the other hand, coastal area also affects Gambus Paser characateristic which tends to be expressive and dynamic. Conceptually speaking, this research is qualitative research with descriptive analytical method. This research focuses on Gambus Paser performing art as the cultural (music) literacy enhancement. The purpose is to analyze the form of Gambus Paser performance as Paser cultural literacy. The result shows that literature related to Paser art is still hardly found, while on the other hand, we have also found how potential this performance as sustainable literacy and identity enhancement for Paser community to welcome the Indonesian capital relocation to East Borneo. A concrete step which is taken is to documenting and disseminating the Gambus Paser performance to create a cultural literacy and a sustainable traditional art.


2021 ◽  
Author(s):  
Jessica Needham ◽  
Joan Webber

Abstract H. fraxineus is an anamorphic fungal pathogen that causes ash dieback. Due to the severity of ash dieback H. pseudoalbidus has been on the EPPO Alert list since 2007. It is not known what caused the emergence of this 'new' disease (NAPPO, 2009). Its spread in Europe is thought to be mainly by ascospores, but infected nursery saplings may carry the fungus to new areas. The entire natural range of known hosts, including North Africa, Russia and south-west Asia (USDA-ARS, 2009), is currently threatened by ash dieback, with large areas already affected (Pautasso et al., 2013). Little is known about the susceptibility of the other species of ash in temperate zones.


Phytotaxa ◽  
2021 ◽  
Vol 522 (1) ◽  
pp. 27-37
Author(s):  
DANIEL F. BRUNTON ◽  
MICHAEL GARRETT ◽  
PAUL C. SOKOLOFF ◽  
GINTARAS KANTVILAS

Isoetes jarmaniae sp. nov. is described as a new lycophyte endemic to Tasmania, Australia, where it is confined to peat-bound karstic wetlands in several river valleys in the south-west wilderness. While seemingly morphologically closest to I. drummondii, this quillwort has features that are globally uncommon in Isoetes and unknown in other Australasian taxa. Most notable are its markedly flattened, strongly recurved leaves and disproportionately large sporangium ligules that are more suggestive of South American than Australian taxa. As well, the exceptionally thin and wide (alate) megaspore equatorial ridge is swollen at suture intersections, presenting a slightly triangular shape suggestive of the Indian taxon I. udupiensis. The microspores of I. jarmaniae exhibit exceptionally, perhaps uniquely, fine-papillate ornamentation. An original key placing I. jarmaniae in context with the other Tasmanian Isoetes species is provided. This diminutive, apparently diploid species is evidently maintaining a self-sustaining population within a regionally unique habitat and small geographic range.


1857 ◽  
Vol 3 ◽  
pp. 294-295
Author(s):  
Robert Harkness

The author remarks that the existence of Annelida during the Palæozoic formations is manifested in two conditions. In the one, we have the shelly envelope which invests the order Tubicola, in the form of Seapolites; and in the other, the tracks of the orders Abranchia and Dorsi-branchiata are found impressed on deposits which were, at one time, in a sufficiently soft state to receive the impressions of the wanderings of these animals.Among the strata which have hitherto afforded annelid tracks, those which, in the county of Clare, represent a portion of the equivalents of the Millstone Grit, contain such tracks, in their most perfect state of preservation in great abundance; and these strata also furnish evidence concerning the circumstances which prevailed during their deposition.


1981 ◽  
Vol 101 ◽  
pp. 78-86 ◽  
Author(s):  
Harold B. Mattingly

The American excavators in the south-west area of the Forum at Corinth have revealed an intriguing architectural complex, which they have called the ‘Punic Amphora Building’. Evidently it housed a thriving import business with a speciality in fish and wine, whose trade extended in one direction to Sicily and perhaps Spain and in the other to Chalkidike and Chios. Masses of fragments of Punic and Chian amphoras were found crushed and pounded in the make-up of successive floor-levels in the courtyard, together with numerous pieces from Mende and elsewhere. Many others emerged from the single floors of most of the rooms or were discovered in the littered debris from the final phase of occupation. The life of this business house was somewhat short, but a domestic building on the same site had earlier been partly devoted to the same trade. All this activity ceased with dramatic suddenness; the emporium went out of use and in the late fifth century it was overlaid in one area by a new road. The end seems to be securely dated c. 430 B.C. by Attic black-glaze pottery in the final floor-level or in the debris covering the last floor. Professor Williams plausibly links the collapse of business with the interruption of Corinth's trade caused by the outbreak of the Peloponnesian War: one of Athens' first war measures was to blockade both the Saronic and the Corinthian Gulfs. This new material evidence for Corinthian commerce is most welcome in itself and, as I hope to show in this paper, it may help clarify other problems.


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