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In the search for a “golden” event to define the GSSP of the Norian Stage (Upper Triassic): bivalve events and their ammonoid calibration
No full textCarnian-Norian halobiids from the Pizzo Mondello section (Sicani Mountains, Sicily, Italy).
No full textAnatomy of carbonate mounds from the Middle Anisian of Nakhlak (Central Iran): architecture and age of a subtidal microbial-bioclastic carbonate factory
Full text linkThe Anisian succession of Nakhlak (in Central Iran) is characterized by a siliciclastic succession with minor carbonate units, with massive carbonate mounds up to 50 m thick in its upper part. The mounds, constrained in age to the late Bithynian (Ismidicus Zone) by ammonoids and conodonts, are characterized by a flat top and a lateral pinch-out marked by clinostratified slopes (about 15A degrees in dip). Stratigraphic and microfacies analyses document an inner part of the mound characterized by massive microbial carbonates with open-space structures (stromatactis) filled with fine-grained internal sediments and marine cements. Isolated sponges (up to 5 cm), serpulids and bryozoans are present, which grew on the calcimicrobial limestone. A narrow bioclastic margin (mainly with crinoids and brachiopods) produces most of the slope facies (consisting of bioclastic grainstone and packstone, with intraclasts from the inner part of the mounds) which interfinger basinward with volcaniclastic sandstones. The demise of carbonate productivity is marked on the top of the carbonate mounds by a condensed surface, rich in ammonoids, glaucony grains, and articulated crinoids, documenting a rapid drowning. Paleolatitude data support deposition in a tropical setting, and sedimentological constraints indicate deposition close to the fair-weather wave base, within the photic zone. The late Bithynian Nakhlak carbonate mounds developed before the appearance (documented since the Pelsonian in different parts of the world) of scleractinians which, despite the favorable environmental conditions, are absent at Nakhlak. The Nakhlak mounds thus represent one of the last occurrences of the microbial factories (which developed after the Permo-Triassic extinction event and persisted for most of the Middle Triassic, but with a gradually increasing role played by scleractinians) before the first appearance of the Mesozoic corals
Anatomy of microbial–bioclastic carbonate mounds from the Middle Anisian of Nakhlak (Central Iran): A genetic model for a shallow subtidal carbonate factory.
No full textThe new Carnian (Norian section of “Pizzo Lupo” (Castronovo di Sicilia, Sicily) and its bearing to the definition of the GSSP of the Norian stage.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The Triassic pre-Cimmerian stratigraphic evolution of Central Iran. MEBE report of the 2004 activity
No full textLATE CARNIAN-EARLY NORIAN AMMONOIDS FROM THE GSSP CANDIDATE SECTION PIZZO MONDELLO (SICANI MOUNTAINS, SICILY)
Full text linkA small collection of ammonoids from the Upper Triassic Scillato Formation at Pizzo Mondello (Agrigento, Sicily) is studied. The specimens were collected in a framework of a project aimed at providing an integrated high-resolution bio-chronostratigraphic support to the Upper Carnian-Norian magnetostratigraphic scale defined at this site, that is located in an historical area from which G.G. Gemmellaro collected the Upper Triassic of ammonoids monographed at the beginning of the XX century. The specimens from Pizzo Mondello were bed-by-bed sampled and represent the first collection of Upper Triassic ammonoids described from Sicily since Gemmellaro time. Quite several levels of the Pizzo Mondello section yielded ammonoids, but very few levels have provided more than one specimen. Due to the scarcity of specimens the taxonomic analysis has been complex because Gemmellaro, who described 166 new species, did not explain the variability of many of his taxa. Sixsteen taxa belonging to eleven genera are described. They include Placites sp. ind., Discotropites plinii (Mojsisovics), Anatropites sp., Microtropites cf. paronai, Metathisbites cf. affinis, Hyattites aff. praefloridus, Projuvavites boehmi (Gemmellaro), Projuvavites inflatus (Gemmellaro), Gonionotites cf. italicus, Gonionotites aff. recuperoi, Dimorphites noricus n. sp., Dimorphites selectus Mojsisovics, Dimorphites sp., Pregriesbachites n. gen. , P. bukowskii (Gemmellaro), Discophyllites insignis. Among the new taxa, Dimorphites noricus n. sp. formalizes the nomen nudum “Dimorphites n. sp. 1” quoted in literature for several years, that is index of the lowest subzone of the Norian stage.
The small collection document the Discotropites plinii and Gonionotites italicus subzones of the uppermost Carnian Spinosus Zone and the Dimorphites noricus and D. selectus subzones of the Jandianus Zone, the first zone of the Lower Norian. This chronostratigraphic classification firmly tie the Pizzo Mondello succession to the Tethyan chronostratigraphic scale, and is crucial for the calibration of the Halobia and conodont bioevents identified in the section. The chronostratigraphic correlations based on ammonoids of the Pizzo Mondello section with Feuerkogel (Austria), Jomsom (Nepal), West Union Canyon (Nevada, USA) and Black Bear Ridge (British Columbia, Canada) is discussed. These are the most complete ammonoid-bearing sections in the world spanning the Carnian/Norian boundary, but all of them show a discrete distribution of ammonoid-bearing beds across the boundary. Ammonoid will not provide the primary marker event for the definition of the GSSP of the Norian, but they are crucial for the selection of the most significant events
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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