Anna Breda, Nereo Preto, Guido Roghi, Stefano Furin, Renata Meneguolo, Eugenio Ragazzi, Paolo Fedele & Piero Gianolla
The Carnian Pluvial Event in the Tofane area (Cortina d‘Ampezzo, Dolomites, Italy)

Geo.Alp 6, 2009, p. 80-115

Introduction
What happened at the end of the Early Carnian, some 235-230 million years ago? All over the Dolomites, the lower-upper Carnian transition is evident from the distance as a break between the majestic rock walls of the massive Cassian Dolomite and those of the well bedded Dolomia Principale. This morphological step is strikingly evident, for example, all around the Sella Platform, and locally evolved to extended plateaus, as below the Tre Cime di Lavaredo or at Lagazuoi, north of Passo Falzarego. Even the slopes of Col Gallina and Nuvolau, uniformly dipping northward toward Passo Falzarego, are structural surfaces representing the exhumed platform top of the demised lower Carnian Cassian Dolomite (Fig. 1). And here our excursion starts.

The aim of this field trip is twofold. On the one hand, evidence will be shown of a climatic swing from arid, to humid, and back to arid climate in the Carnian of the Tofane area. We here denote the whole climatic episode, regardless of its polyphase nature, as the “Carnian Pluvial Event”. On the other hand, the effects of this climatic event on sedimentation and biota will be illustrated, from the km scale of carbonate platform geometries to the smaller scale of facies associations and lithologies. The morphological features of famous mountain groups of the Dolomites, as depicted above, are a direct consequence of the sedimentary turnover triggered by the Carnian Pluvial Event.

The locality we have chosen for this purpose is the area at the foot of the Tofane mountains, with the sections at Passo Falzarego and Rifugio Dibona, the last one probably the best exposed and complete section encompassing the Carnian Pluvial Event (Fig. 1). The Tofane mountains face the “conca di Cortina”, at the heart of the Dolomites, a paradise for mountain lovers. We hope to convince you that this is also a paradise for earth scientists.


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