Paleontological studies of Cretaceous vertebrate fossil beds in the Tataouine Basin (southern Tunisia)

The ‘Continental Intercalaire’ deposits of the Tataouine basin of southern Tunisia preserve one of the most diverse Cretaceous vertebrate fauna from Africa. This research project focuses on a detailed revision of the stratigraphic distribution of mid-Cretaceous fossil beds in the Tataouine Basin and includes the description of four, newly discovered vertebrate tracksites. In the Tataouine region, macro- and microvertebrate remains are recovered from three stratigraphic intervals: the lower Douiret Formation (Barremian), the Chenini (rare) and Oum ed Diab members of the Aïn El Guettar Formation (Albian). A detailed, basin-scale revision of the stratigraphic occurrence of fossil-bearing strata indicates 1. lateral facies variability within the context of a low gradient, circalittoral to coastal-plain environment; 2. multiple and diachronous fossil beds which include elasmobranchs, actinopterygians, sarcopterygians, turtles, crocodyliforms, pterosaurs, and non-avian dinosaurs remains. Four vertebrate tracksites have been discovered in the study area: 1. the Middle Jurassic Beni Ghedir site which preserves approximately 130 tridactyl footprints distributed over an area of 200 square meters, representing the oldest evidence of a dinosaur fauna in Tunisia; 2. the late Albian Chenini tracksite, which includes poorly preserved crocodilian tracks and the dinosaur ichnospecies Apulosauripus federicianus; 3. the Cenomanian Ksar Ayaat locality, where footprints assigned to a pleurodiran turtle are exposed, and 4. the upper Cenomanian Jebel Boulouha site which presents almost 100 well-preserved tridactyl tracks referred to small-sized theropods, fossil bird tracks - ichnogenus Koreanaorins – and tracks referred to a mammalian trackmaker, representing the first report of fossil bird and mammal from the Cretaceous of continental Africa and Tunisia respectively. In addition, data collected from the Tunisian tracksites have been compared with coeval tracksites in Italy and Croatia, showing analogies in morphology and paleoenvironment of dinosaur ichnoassociations, supporting the already hypothesized subaerial connection between these areas during the mid-Cretaceous.

Maremoti in bacini limitati

The work of my thesis is focused on the impact of tsunami waves in limited basins. By limited basins I mean here those basins capable of modifying significantly the tsunami signal with respect to the surrounding open sea. Based on this definition, we consider limited basins not only harbours but also straits, channels, seamounts and oceanic shelves. I have considered two different examples, one dealing with the Seychelles Island platform in the Indian Ocean, the second focussing on the Messina Strait and the harbour of the Messina city itself (Italy). The Seychelles platform is differentiated at bathymetric level from the surrounding ocean, with rapid changes from 2 km to 70 meters over short horizontal distances. The study of the platform response to the tsunami propagation is based on the simulation of the mega-event occurred on 26 December 2004. Based on a hypothesis for the earthquake causative fault, the ensuing tsunami has been numerically simulated. I analysed synthetic tide gauge records at several virtual tide gauges aligned along the direction going from the source to the platform. A substantial uniformity of tsunami signals in all calculated open ocean tide-gauge records is observed, while the signals calculated in two points of the Seychelles platform show different features both in terms of amplitude and period of the perturbation. To better understand the content in frequency of different calculated marigrams, a spectral analysis was carried out. In particular the ratio between the calculated tide-gauge records spectrum on the platform and the average tide-gauge records in the open ocean was considered. The main result is that, while in the average spectrum in the open ocean the fundamental peak is related to the source, the platform introduces further peaks linked both to the bathymetric configuration and to coastal geometry. The Messina Strait represents an interesting case because it consists in a sort of a channel open both in the north and in the south and furthermore contains the limited basin of the Messina harbour. In this case the study has been carried out in a different way with respect to the Seychelles case. The basin was forced along a boundary of the computational domain with sinusoidal functions having different periods within the typical tsunami frequencies. The tsunami has been simulated numerically and in particular the tide-gauge records were calculated for every forcing function in different points both externally and internally of the channel and of the Messina harbour. Apart from the tide-gauge records in the source region that almost immediately reach stationarity, all the computed signals in the channel and in the Messina harbour present a transient variable amplitude followed by a stationary part. Based exclusively on this last part, I calculated the amplification curves for each site. I found that the maximum amplification is obtained for forcing periods of approximately 10 minutes.

Development discourse in Romania: from Socialism to EU Membership

With their accession to the European Union, twelve new countries - Romania among them - (re)entered the international community of international donors. In the history of development aid this can be seen as a unique event: it is for the first time in history that such a large number of countries become international donors, with such short notice and in such a particular context that sees some scholars announcing the ‘death’ of development. But in spite of what might be claimed regarding the ‘end’ of the development era, development discourse seems to be rather vigorous and in good health: it is able to extert an undeniable force of attraction over the twelve countries that, in a matter of years, have already convinced themselves of its validity and adhered to its main tenets. This thesis collects evidence for improving our understanding of this process that sees the co-optation of twelve new countries to the dominant theory and practice of development cooperation. The evidence collected seems to show that one of the tools employed by the promoters of this co-optation process is that of constructing the ‘new’ Member States as ‘new’, inexpert donors that need to learn from the ‘old’ ones. By taking a case-study approach, this thesis gathers data that suggests that conceiving of the ‘twelve’ as ‘new’ donors is both historically inaccurate and value-ladden. On one hand, Romania’s case-study illustrates how in the (socialist) past at least one in the group of the twelve was particularly conversant in the discourse of international development. On the other hand, the process of co-optation, while being presented as a knowledgeproducing process, can also be seen as an ignorance-producing procedure: Romania, along with its fellow new Member States, takes the opportunity of ‘building its capacity’ and ‘raising its awareness’ of development cooperation along the line drawn by the European Union, but at the same time it seems to un-learn and ‘lower’ its awareness of development experience in the (socialist) past. This is one possible reading of this thesis. At a different level, this thesis can also be seen as an attempt to account of almost five decades of international development discourse in one specific country – Romania – in three different socio-political contexts: the socialist years (up to the year 1989), the ‘transition years’ (from 1989 to the pre-accession years) and the membership to the European Union. In this second reading, the thesis seeks to illustrate how – contrary to widespread beliefs – before 1989 Romania’s international development discourse was particularly vivid: in the most varied national and international settings President Ceausescu unfolded an extensive discursive activity on issues pertaining to international development; generous media coverage of affairs concerning the developing countries and their fight for development was the rule rather than the exception; the political leadership wanted the Romanians not only to be familiarized with (or ‘aware of’ to use current terminology) matters of underdevelopment, but also to prove a sense of solidarity with these countries, as well as a sense of pride for the relations of ‘mutual help’ that were being built with them; finally, international development was object of academic attention and the Romanian scholars were able not only to reflect on major developments, but could also formulate critical positions towards the practices of development aid. Very little remains of all this during the transition years, while in the present those who are engaged in matters pertaining to international development do so with a view of building Romania as an EU-compliant donor.

Provenienza dei sedimenti arenitici nel bacino di Tracia (eo-oligocene, Turchia nord-occidentale e Grecia nord-orientale)

The Thrace Basin is the largest and thickest Tertiary sedimentary basin of the eastern Balkans region and constitutes an important hydrocarbon province. It is located between the Rhodope-Strandja Massif to the north and west, the Marmara Sea and Biga Peninsula to the south, and the Black Sea to the est. It consists of a complex system of depocenters and uplifts with very articulate paleotopography indicated by abrupt lateral facies variations. Its southeastern margin is widely deformed by the Ganos Fault, a segment of the North Anatolian strike-slip fault system . Most of the Thrace Basin fill ranges from the Eocene to the Late Oligocene. Maximum total thickness, including the Neogene-Quaternary succession, reaches 9.000 meters in a few narrow depocenters. This sedimentary succession consists mainly of basin plain turbiditic deposits with a significant volcaniclastic component which evolves upwards to shelf deposits and continental facies, with deltaic bodies prograding towards the basin center in the Oligocene. This work deals with the provenance of Eocene-Oligocene clastic sediments of the southern and western part of Thrace Basin in Turkey and Greece. Sandstone compositional data (78 gross composition analyses and 40 heavy minerals analyses) were used to understand the change in detrital modes which reflects the provenance and geodinamic evolution of the basin. Samples were collected at six localities, which are from west to est: Gökçeada, Gallipoli and South-Ganos (south of Ganos Fault), Alexandroupolis, Korudağ and North-Ganos (north of Ganos Fault). Petrologic (framework composition and heavy-mineral analyses) and stratigraphic-sedimentologic data, (analysis of sedimentologic facies associations along representative stratigraphic sections, paleocurrents) allowed discrimination of six petrofacies; for each petrofacies the sediment dispersal system was delineated. The Thrace Basin fill is made mainly of lithic arkoses and arkosic litharenites with variable amount of low-grade metamorphic lithics (also ophiolitic), neovolcanic lithics, and carbonate grains (mainly extrabasinal). Picotite is the most widespread heavy mineral in all petrofacies. Petrological data on analyzed successions show a complex sediment dispersal pattern and evolution of the basin, indicating one principal detrital input from a source area located to the south, along both the İzmir-Ankara and Intra-Pontide suture lines, and a possible secondary source area, represented by the Rhodope Massif to the west. A significant portion of the Thrace Basin sediments in the study area were derived from ophiolitic source rocks and from their oceanic cover, whereas epimetamorphic detrital components came from a low-grade crystalline basement. An important penecontemporaneous volcanic component is widespread in late Eocene-Oligocene times, indicating widespread post-collisional (collapse?) volcanism following the closure of the Vardar ocean. Large-scale sediment mass wasting from south to north along the southern margin of the Thrace Basin is indicated (i) in late Eocene time by large olistoliths of ophiolites and penecontemporaneous carbonates, and (ii) in the mid-Oligocene by large volcaniclastic olistoliths. The late Oligocene paleogeographic scenario was characterized by large deltaic bodies prograding northward (Osmancik Formation). This clearly indicates that the southern margin of the basin acted as a major sediment source area throughout its Eocene-Oligocene history. Another major sediment source area is represented by the Rhodope Massif, in particolar the Circum-Rhodopic belt, especially for plutonic and metamorphic rocks. Considering preexisting data on the petrologic composition of Thrace Basin, silicilastic sediments in Greece and Bulgaria (Caracciolo, 2009), a Rhodopian provenance could be considered mostly for areas of the Thrace Basin outside our study area, particularly in the northern-central portions of the basin. In summary, the most important source area for the sediment of Thrace Basin in the study area was represented by the exhumed subduction-accretion complex along the southern margin of the basin (Biga Peninsula and western-central Marmara Sea region). Most measured paleocurrent indicators show an eastward paleoflow but this is most likely the result of gravity flow deflection. This is possible considered a strong control due to the east-west-trending synsedimentary transcurrent faults which cuts the Thrace Basin, generating a series of depocenters and uplifts which deeply influenced sediment dispersal and the areal distribution of paleoenvironments. The Thrace Basin was long interpreted as a forearc basin between a magmatic arc to the north and a subduction-accretion complex to the south, developed in a context of northward subduction. This interpretation was challenged by more recent data emphasizing the lack of a coeval magmatic arc in the north and the interpretation of the chaotic deposit which outcrop south of Ganos Fault as olistoliths and large submarine slumps, derived from the erosion and sedimentary reworking of an older mélange unit located to the south (not as tectonic mélange formed in an accretionary prism). The present study corroborates instead the hypothesis of a post-collisional origin of the Thrace Basin, due to a phase of orogenic collapse, which generated a series of mid-Eocene depocenters all along the İzmir-Ankara suture (following closure of the Vardar-İzmir-Ankara ocean and the ensuing collision); then the slab roll-back of the remnant Pindos ocean played an important role in enhancing subsidence and creating additional accommodation space for sediment deposition.

Forma breve e fotografia: una narrativa del Mozambico

La relazione interdisciplinare tra letteratura e fotografia, nella rilettura della storia recente del Mozambico, è l’oggetto di studio della presente tesi. Il presupposto coincide in primo luogo con la disamina interna della dialettica esistente tra archivio coloniale e oralità, modalità narrativa in parte transitata nella estória, declinazione lusofona della forma breve che permette di recuperare l’eredità popolare del racconto tradizionale. Il dialogo tra verbale e visuale consente a sua volta di stabilire nuovi paradigmi interpretativi nel dibattito postcoloniale tra memoria, trauma e rappresentazione. L’analisi comparativa tra la narrativa di João Paulo Borges Coelho e la fotografia di Ricardo Rangel rivela sguardi diversi sul mondo circostante, ma anche convergenze contemplative che si completano nell’incorporazione reciproca delle “omologie strutturali” comuni alle due modalità espressive. La fotografia colma delle lacune fornendoci delle visioni del passato, ma, in quanto “rappresentazione”, ci mostra il mondo per come appare e non per come funziona. Il testo letterario, grazie al suo approccio dialogico-narrativo, consente la rielaborazione museologica della complessa pletora di interferenze semantiche e culturali racchiuse nelle immagini, in altre parole fornisce degli “indizi di verità” da cui (ri)partire per l’elaborazione di nuovi archetipi narrativi tra l’evento rappresentato e la Storia di cui fa parte. Il punto di tangenza tra i due linguaggi è la cornice, espediente fotografico e narrativo che permette di tracciare i confini tra l’indicibile e l’invisibile, ma anche tra ciò che si narra e ciò che sta fuori dalla narrazione, ovvero fuori dalla storia. La tensione dialettica che si instaura tra questi due universi è seminale per stabilire le ragioni della specificità letteraria mozambicana perché, come afferma Luandino Vieira, “nel contesto postcoloniale gli scrittori sono dei satelliti che ruotano intorno ai «buchi neri della storia» la cui forza di attrazione permette la riorganizzazione dell’intero universo letterario.

Still/moving images. Il rapporto dialettico tra cinema e fotografia nelle pratiche artistiche contemporanee.

Tra le plurime conseguenze dell’avvento del digitale, la riarticolazione dei rapporti tra immagine statica e immagine in movimento è certamente una delle più profonde. Sintomatica dei cambiamenti in atto sia nei film studies sia nella storia dell’arte, tale riarticolazione richiede un ripensamento dei confini disciplinari tradizionali entro cui il cinema e la fotografia sono stati affrontati come oggetti di studio separati e distinti. Nell’adottare un approccio molteplice, volto a comprendere prospettive provenienti dalla New Film History e dalla media archaeology, dalla teoria dell’arte e dagli studi visuali, questo lavoro esplora l’esistenza di una relazione dialettica tra il cinema e la fotografia intesa in modo duplice: come tensione costitutiva tra due media indissolubilmente connessi – non tanto in considerazione di un medesimo principio realistico di rappresentazione quanto, piuttosto, in virtù di uno scambio incessante nella modellizzazione di categorie quali il tempo, il movimento, l’immobilità, l’istante, la durata; come istanza peculiare della pratica artistica contemporanea, paradigma di riferimento nella produzione estetica di immagini. La tesi si suddivide in tre capitoli. Il primo si concentra sul rapporto tra l’immobilità e il movimento dell’immagine come cifra in grado di connettere l’estetica delle attrazioni e la cronofotografia a una serie di esperienze filmiche e artistiche prodotte nei territori delle avanguardie. Il secondo capitolo considera l’emergenza, dagli anni Novanta, di pratiche artistiche in cui l’incontro intermediale tra film e fotografia fornisce modelli di analisi volti all’indagine dell’attuale condizione estetica e tecnologica. Il terzo offre una panoramica critica su un caso di studio, la GIF art. La GIF è un formato digitale obsoleto che consente di produrre immagini che appaiono, simultaneamente, come fisse e animate; nel presente lavoro, la GIF è discussa come un medium capace di contraddire i confini attraverso cui concepiamo l’immagine fissa e in movimento, suggerendo, inoltre, un possibile modello di pensiero storico-cronologico anti-lineare.