TESTIMONIANZE Dl ATTIVITA' TETTONICA TARDOTRIASSICA NELLE PREALPI VICENTINE

In the Recoaro area (Northern Italy) a channelized breccia containing abundant metamorphic clasts of the crystalline basement is interbedded in the Iower part of the Dolomia Principale formation (Upper Triassic) The breccia is interpreted as a fluvial deposit, which momentarily interrupted the cyclic sedimentation of the Dolomia Principale. This event is connected with a local tectonic phase The instability rnay be related to a more important tectonic activity which involved a region located South of the Recoaro area

Carnian stratigraphy in the Raibl/Cave del Predil area (Julian Alps, Italy)

The analysis of the type-sections of the Tor Formation and Carnitza Formation in the neighbourhood of Raibl/Cave del Predil (southern Julian Alps) allows a better definition of the Upper Carnian stratigraphic and sequence stratigraphic setting in this classical area. Ammonoids and palynomorphs confine the age of a part of the Conzen Formation, of the Tor Formation, of the Carnitza Formation and of the base of the Dolomia Principale to the Tuvalian. The Conzen Formation and the Tor Formation respectively correspond to the Dürrenstein Formation and the Raibl Formation in the Dolomites. In the Tarvisio area, a margin-foreslope system of the Dolomia Principale in front of its basin (Carnitza Formation) is exceptionally preserved at a seismic-scale and allows a better comprehension of the start-up of the Dolomia Principale carbonate platform.The analysis of the type-sections of Tor Formation and Carnitza Formation in the neighbourhood of Raibl/Cave del Predil (Tarvisio area, Julian Alps, Italy) allows a better definition of the Carnian stratigraphic and sequence stratigraphic framework in this classical area. Ammonoids and palynomorphs confine the age of the Conzen Formation and of most of the Tor Formation to the Julian, while the uppermost Tor Formation, the Carniza Formation and the base of the Dolomia Principale are Tuvalian in age. In the Tarvisio area, a margin-foreslope system of the Dolomia Principale, interfingering with basinal sediments (Carnitza Formation) is exceptionally well preserved at a seismic-scale. This setting allows a better comprehension of the start-up of the Dolomia Principale carbonate platform

Triassic Sequence Stratigraphy in the Southern Alps. Definition of sequences and basin evolution.

In the Southern Alps a number of 3rd order depositional sequences have been observed, far more than previously known: of these 6 develop principally in the Scythian, 4 in the Anisian, 3 in the Ladinian, 4 in the Carnian, at least 2 in the Norian and finally 2 in the Rhaetian. Lower Anisian to Lower Carnian depositional sequences are best dated by ammonoids, while in the Scythian ammonoids and conodonts are scanty. In the Upper Carnian, Norian and Rhaetian of the Southern Alps very rare ammonoids and conodonts are available. Therefore Scythian, Upper Carnian, Norian and Rhaetian depositional sequences have throughout been defined on the basis of stratal patterns and the evolution of facies, being their chronostratigraphical position inferred from sections elsewhere in the world. The contemporaneous analysis of platforms and basins, and of carbonate, mixed and siliciclastic deposits, has made a good comprehension of facies migration possible. This approach was crucial in the definition of 3rd order depositional sequences. Moreover, on the basis of the previously defined 3rd order sequences and systems tracts, a number of 2nd order transgressive-regressive cycles have been pointed out. The sequence stratigraphic analysis compared with the tectonic history allowed the definition of the different phases of the basin evolution

An Upper Tuvalian (Triassic) platform-basin system in the Julian Alps: The start-up of the Dolomia Principale (Southern Alps, Italy)

East of Cave del Predil (formerly Raibl), a platform-basin transition of the Dolomia Principale (Hauptdolomit) is spectacularly exposed at a seismic scale. Therefore, the eastern margin of the vast domain of the Dolomia Principale, facing the Slovenian Basin, is documented. Despite of strong dolomitization of the massive margin, some sedimentary structures and fossils have been recognized. Corals seem to be very rare and sponges to be absent, whereas serpulids and marine phreatic cements seem to have been the main components of the framework. Interior platform bedded dolomites lap off the massive margin. Clinoforms interfinger with upper Tuvalian basinal deposits (Carnitza Formation). This setting documents the start-up of the Dolomia Principale during late Tuvalian time. Moreover, this margin of the Dolomia Principale is the more ancient so far pointed out. It testifies to the recovery of a rimmed platform after the late Julian-early Tuvalian crisis

Note Illustrative della Carta Geologica d'Italia alla scala 1:50.000, Foglio 082 Asiago

Descrizione della geologia dell'area di Asiag

A middle Triassic back-stepping carbonate platform in the Dolomites (Italy): sequence stratigraphy and biochronostratigraphy

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Carnian-Norian paleogeography in the eastern Southern Alps

A detailed analysis of Upper Triassic basinal successions from Eastern Cadore, Carnia and Julian Alps allows us the reconstruction of the paleogeography of this important sector of the Southern Alps. The presence of Tuvalian basinal facies at the toe of slope of a prograding carbonate platforms in the Santo Stefano di Cadore area and the correlation with similar succession in the Julian Alps testifying the presence of a distinct branch of the Slovenian Basin here called Tarvisio Basin

Triassic sequence stratigraphy in the Dolomites (Italy).

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