1,821 research outputs found
A Pridoli-Lochkovian conodont zonation in Sardinia and the Carnic Alps: implications for a global zonation scheme
No full textThe main conodont zonation schemes for the Pridoli and the Lochkovian presents some problems that make difficult their use in several geographical areas. Data from several sections in Sardinia and the Carnic Alps not only allow to built a regional zonation scheme for these areas, but also suggest possible solutions of global validity. In the Carnic Alps and Sardinia, the Přídolí is subdivided into three zones: Eosteinhornensis s.l., Lower and Upper detortus. The latter results after the subdivision of the former detortus Zone on the basis of the Last Appearance Datum of some coniform species (Dapsilodus obliquicostatus, Coryssognathus dubius and Panderodus recurvatus) that became extinct almost simulta-neously in the latest Přídolí. Daps. obliquicostatus is chosen as the marker, being the most common and easily identifi-able species. In the Lochkovian six zones are discriminated: Hesperius, carlsi, transitans, eleanorae, trigonicus and pan-dora β. The hesperius Zone, which includes the postwoschmidti subzone in its upper part, is expanded to include most of the eurekaensis zone of the "global" scheme, because the marker Oz. eurekaensis is not present. The carlsi Zone corre-sponds to the upper part of the eurekaensis Zone and to the lower part of the former mid-Lochkovian delta Zone (= omoalpha Zone). The rest of the Middle Lochkovian is subdivided into the three zones (transitans, eleanorae and trigonicus) already proposed in Nevada and Spain, followed by the pandora β Zone. All the zones are discussed and checked for their applicability in other palaeogeographical regions
Litho-, Chrono- and conodont bio-stratigraphy of the Rauchkofel Boden Section (Upper Ordovician-Lower Devonian), Carnic Alps, Austria.
No full textAn updated stratigraphy of the Rauchkofel Boden Section, a classical reference section for the Carnic Alps that exposes rocks from the Katian (Upper Ordovician) to the Pragian (Lower Devonian) is here presented, following latest developments in conodont taxonomy and biostratigraphy, as well as in chronostratigraphy, and the recent introduction of a new lithostratigraphic outline of the Carnic Alps. The original conodont collection of the ’70s and ʼ80s was restudied and complemented by a detailed resampling in order to achieve a more precise conodont biostratigraphic assignment. Twenty-five conodont Zones are now documented. The lithostratigraphy is precisely fixed to the new lithostratigraphic scheme of the Pre-Variscan sequence by definition of seven distinct formations. Finally, the position of chronostratigraphic boundaries is discussed
The Devonian sequence at the Mt Freikofel (Carnic Alps, Austria-Italy)
No full textThe Mt Freikofel at the Austria-Italy border is
constituted of one of the best, and most complete
Devonian sequence of the Carnic Alps (Fig. 1). It was
not disrupted by the Variscan and Alpine tectonics,
and it is quite easy to follow on the field due to the
special morphology of the mount. The sequence is
made by seven calcareous formations representing
different depositional settings within the lower
Palaeozoic Carnic basin. These lithostratigraphic units
yield more or less rich conodont faunas that allowed
to set a date in terms of conodont biostratigraphy to
the whole sequence
Findenig Formation
No full textThe Findenig Formation consists of red to pink nodular centimetric thick beds of mudstone/wackestone, with interlayered millimetric to centimetric red marls, and, at places, some centimetric to decimetric calcarenitic (grainstone) intervals (allodapic layers) and breccia (calcirudite) beds in the upper part of the unit
The Silurian of the Foreland Zone (southwestern Sardinia)
No full textThe Silurian exposed in southwestern Sardinia is well-known for its precious faunal content. Lower part of the sequence consists of black graptolitic shales (Genna Muxerru Formation) comprising much of the Llandovery. It is suceeded by a calcareous unit (Fluminimaggiore Formation), locally rich in cephalopods, covering the rest of the Silurian. Even the Lower Devonian is represented by limestones. A precise and detailed biostratigraphical assignment of the units has been achieved by graptolites and conodonts
Rauchkofel Formation
No full textThe Rauchkofel Formation mainly consists of dark gray to black laminated and well-bedded, partly platy limestones intercalated with black shales and marls of various thickness. Lateral variations are common.
Thickness of beds varies from very thin to medium for limestones. Black graptolitic shales with graptolites are more abundant in the lower part of the unit, where they may constitute levels up to 15 cm thick. In the proximal parts of the basin thick to very thick calcarenitic beds and breccias occur more frequently in the upper part of the unit, but in places they may occur also in the lowermost part. A distinct horizon with loboliths is present in the lowermost part of the formation
Geology and stratigraphy of the Cason di Lanza area (Mount Zermula, Carnic Alps, Italy)
No full textIn the Cason di Lanza-Mt. Zermula area rocks from
Ordovician to Permian are exposed. They belong to the "Variscan sequence" and to the "Permo–Carboniferous sequence" of the Carnic Alps. The structural settings and the stratigraphic sequence
of neritic and pelagic deposits are described
A short overview on the Palaeozoic sequence of the Carnic Alps
No full textAn overview of the geological evolution of the Carnic Alps during the Palaeozoic is presented: the Variscan sequence, the Permo–Carboniferous sequence and the basal part of the Alpine sequence were deposited between the Late Ordovician and the Middle Triassic
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