Geološka povijest rijeke Drave u Koruškoj (Austrija) - poznate činjenice i opis projekta

The Drava is the largest and most important river of Carinthia (Austria), as it is used for economical as well as for recreation purposes. Hydrogeologically it is the main drainage system. As the information on the geology of the riverbed and its development are distributed in numerous publications and partly even hidden in unpublished geological reports the aim of the project is to summarize and replenish these data. At present the Drava passes different petrographic areas following paths pre-sketched by older geological faults such as the Periadriatic Lineament. The geological history of a pre-existing Drava in the sense of the main drainage system from the High Tauern to the East begins roundabout 12 Mya ago when Carinthia gets continental. The general direction of the water runoff from the Northwest to the South and East is similar to the present as due to the rising of the Central Alps in Carinthia intramontane basin at lower levels has been established at that time. In the Pannonian or even already in the Sarmatian the river course in lower Carinthia is assumed north of its present riverbed, running through the Klagenfurt basin, which has been filled up by tertiary sediments. During the Pleistocene Carinthia has been covered almost completely with ice and the valley and the river bed has been overprinted by the great Drava glacier. With the melting of the glaciers the valleys have been filled up with hundreds of meters of sediments. Nowadays the Drava is influenced by anthropogenic activities such as regulations.Drava je najveća i najvažnija rijeka u Koruškoj (Austrija), te se koristi u gospodarske svrhe i za rekreaciju. S hidrogeološkog aspekta rijeka Drava je glavni vodotok. Obzirom na činjenicu da su informacije o geologiji korita i njegovog razvoja prisutni u brojnim publikacijama, a neki su djelomično skriveni u neobjavljenim geološkim izvješćima, cilj ovog projekta je sažeti i nadopuniti te podatke. Drava trenutno prolazi kroz različita petrografska područja kroz tokove koji su rezultat starijih geoloških nedostataka poput perijadranskog rasjeda. Geološka povijest prapovijesne Drave kao glavnog vodotoka s Visokih Tura prema istoku počinje prije 12 milijuna godina kada Koruška postaje kontinentalno područje. Glavni smjer otjecanja vode sa sjeverozapada prema jugu i istoku je sličan sadašnjem zbog tadašnjeg izdizanja Središnjih alpi u međuplanonskom bazenu Koruške. U panonskom i sarmacijskom periodu tok rijeke u Koruškoj bio je sjevernije od sadašnjeg korita i prolazio je kroz bazen u području Klagenfurta koji je bio ispunjen tercijarnim sedimentima. Za vrijeme pleistocena Koruška je bila gotovo u potpunosti prekrivena ledom, a nizina i rijeka su bili prekriveni velikim Dravskim glečerom. Otapanjem glečera doline su bile zapunjene stotinama metara sedimenta. U današnje vrijeme na Dravu utječu antropogene aktivnosti poput zakonskih odredbi

Early Devonian Ostracods of Celtiberia (NE Spain): taxonomy, palaeoecology, biostratigraphy, and biogeography

From numerous successive, well dated horizons of Early Lochkovian to Zlichovian age in Celtiberia (NE Spain), 93 neritic ostracod taxa of 40 genera are described and evaluated. 8 new species are named, further 10 new species are held in open nomenclature. The great potential of the Celtiberian Early Devonian for biostratigraphy is made available for work with ostracods. The ostracod records from outside Celtiberia are revised and redated. The ranges of many ostracod taxa are refined. The ostracod assemblages belong to the Eifelian Ecotype sensu Becker, 1975, but three recurring associations can be distinguished. Spinose forms of true Thuringian Ecotype do not occur. New faunistic data reveal the biogeographical relations in the Early Devonian between Gondwana and Baltica-Avalonia. The similarities among Celtiberian, other European, and NW African ostracod faunas are evaluated with due regard to their age relations. The Celtiberian faunas are closely related to those of Armorica. Neritic ostracods common to Celtiberia, Armorica and NW Africa corroborate the continuity of the Ibarmaghian Faunal Province. Due to the different ages and facies, there are only few similarities between the ostracod faunas of Celtiberia and those of nearby Cantabria and Montagne Noire. Faunal links between Celtiberia and Laurussia exist, but are scarce. Ostracod relations between Celtiberia and the Rheno-Ardennan basin, although not with certainty on species level, are evident from the Mittlere Siegen Schichten onward. The occurrence of beyrichiacean ostracods in Ibero-Armorica, at least from the mid-Lochkovian onward, disproves a wide Early Devonian "Rheic Ocean" between Baltica-Avalonia and Gondwana and supports the palaeogeographical reconstruction by McKerrow et al. (2000) that postulates the vicinity of Gondwana and Laurussia for Early Devonian times.Aus zahlreichen gut datierten sukzessiven Horizonten des Unter-Lochkoviums bis Zlichoviums in Keltiberien (NE Spanien) werden 93 neritische Ostrakoden-Taxa aus 40 Gattungen beschrieben. Acht neue Arten werden benannt, weitere 10 neue Arten verbleiben in offener Nomenklatur. Das große biostratigraphische Potential des Unterdevons Keltiberiens wird für die Arbeit mit Ostrakoden nutzbar gemacht. Ostrakoden-Fundpunkte außerhalb Keltiberiens werden neu datiert, die Reichweite vieler Ostrakoden-Taxa werden präzisiert. Die Ostrakoden-Vergesellschaftungen sind dem Eifeler Ökotyp sensu Becker, 1975 zuzurechnen, dabei lassen sich drei wiederkehrende Assoziationen erkennen. Bestachelte Taxa des echten Thüringer Ökotpys sind nicht vertreten. Den palaeogeographischen Beziehungen zwischen Gondwana und Baltica werden neue Daten hinzugefügt. Beim Vergleich der Ostrakoden-Faunen aus Keltiberien, dem übrigen Europa und NW Afrika werden hier die genauen Altersbeziehungen der Fundhorizonte berücksichtigt. Die Übereinstimmungen zwischen Keltiberien, Armorica und NW Afrika bestätigen die "Ibarmaghian Faunal Province". Die Beziehungen zu den Faunen Kantabriens und der Montagne Noire sind wegen Alters- und Fazies-Unterschieden vergleichsweise gering. Nur wenige prä-Emsische Faunenbeziehungen zwischen Keltiberien und Laurussia konnten nachgewiesen werden. Die frühesten Verbindungen von Keltiberien zum Rheinisch-Ardennischen Trog sind ab den Mittleren Siegen Schichten zu belegen, obwohl nicht mit Sicherheit Artgleichheiten bestehen. Das Vorkommen beyrichiider Ostrakoden in Keltiberien ab der Mitte des Lochkovium spricht gegen einen früh-devonischen "Rheischen Ozean" zwischen Baltica-Avalonia und Gondwana. Dieses unterstützt das paläogeographische Modell von McKerrow et al. (2000), nach der Gondwana und Laurussia im Unterdevon dicht benachbart sind

Freikofel Formation

peer reviewe

Insight into the development of a carbonate platform through a multi-disciplinary approach - A case study from the Upper Devonian slope deposits of Mount Freikofel (Carnic Alps, Austria/Italy)

The development and behavior of Million year-scaled depositional sequences recorded within Palaeozoic carbonate platform has remained poorly examined. Therefore, the understanding of palaeoenvironmental changes that occur in geological past is still limited. We herein undertake a multi-disciplinary approach (sedimentology, conodont biostratigraphy, magnetic susceptibility and geochemistry) of a long-term succession in the Carnic Alps which offers new insights into the peculiar evolution of one of the best example of Palaeozoic carbonate platform in Europe. The Freikofel section, located in the central part of the Carnic Alps represents an outstanding succession in a fore-reef setting, extending from the latest Givetian (indet. falsiovalis conodont Zones) to the early Famennian (Lower crepida conodont Zone). Sedimentological analysis allowed to propose a sedimentary model dominated by distal slope and fore-reef slope deposits. The most distal setting is characterized by an autochthonous pelagic sedimentation showing local occurrence of thin-bedded turbiditic deposits. In the fore-reef slope, in a more proximal setting, there is an accumulation of various autochthonous and allochthonous fine- to coarse-grained sediments originated from the interplay of gravity-flow currents derived from the shallow-water and deeper-water area. The temporal evolution of microfacies in the Freikofel section evolves in two main steps corresponding to the Freikofel (Unit 1) and the Pal (Unit 2) Limestones. Distal slope to fore-reef lithologies and associate changes are from base to top of the section: (U1) thick bedded litho- and bioclastic breccia beds with local fining upward sequence and fine-grained mudstone intercalations corresponding, in the fore-reef setting, to the dismantlement of the Eifelian – Frasnian carbonate platform during the early to late Frasnian time (falsiovalis to rhenana superzones) with one of the causes being the Late Givetian major rift pulse; (U2) occurrence of thin-bedded red nodular and cephalopod-bearing limestones with local lithoclastic grainstone intercalations corresponding to a significant deepening of the area and the progressive withdrawal of sedimentary influxes toward the basin, in relation with late Frasnian sea-level rise. Magnetic susceptibility and geochemical analyses were also performed along the Freikofel section and demonstrate the inherent-parallel link existing between variation in magnetic susceptibility values and proxy for terrestrial input. Interpretation of magnetic susceptibility in term of palaeoenvironmental processes reflect that even though distality remains the major parameter influencing magnetic susceptibility values, carbonate production and water agitation also play an important role.Grants IGCP 580 and NAP0017 (DP, ACDS), the FWF P 23775-B17 (TS and EK