DOLOMITES - Annexes 2-8 - Provincia di Udine

NOMINATION OF THE DOLOMITES FOR INSCRIPTION ON THE WORLD NATURAL HERITAGE LIST UNESCO
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Airview of the ravine of Bletterbach
the Permian-triassic boundary and the Werfen formation
The Bellerophon Formation is succeeded (overlain) by the Werfen Formation. This complexity of
this historic unit is the result of a terrigenous-carbonate ramp environment (Roter und bunter Schiefer
von Werfen, Lill von Lillienbach, 1830; Werfener Schichten, Bronn, 1832; Seiser Schichten and Campiler
Schichten, Richthofen, 1860), composed of a variety of lithologic types from carbonate to terrigenous
(oolithic and bioclastic calcarenites, more or less marly micrites, marlstones, siltites, arenaceous
limestones, silty and arenaceous dolomites, etc.), normally finely bedded.
The Werfen Formation has been subdivided into nine subunits (members and horizons) based on
the macroscopic lithostratigraphic characteristics (prevalent lithologies, color, strongly evident fossiliferous
levels) (Bosellini, 1968; Rossi, 1969; Farabegoli et alii, 1977; Pisa et alii, 1979; Broglio
Loriga et alii, 1983; 1990; Neri & Posenato, 1988).
At the base of the Formation a level of oolitic limestones (Tesero Member) can be found which
represents the passage of the underlying Permian Bellerophon Formation to the Triassic. Going up
through the stratigraphic series, after the Mazzin and Andraz Members, one can find the Siusi Member,
made up of gray marly limestones rich in Claraia clarai, an important lamellibranch guide fossil;
or farther up, after the Gastropod Oolite, the Campil Member, documented by red sandstones
characterized by the abundant starfish (Ophiuroids) and the sedimentary structures such as ripple
marks. The Val Badia Member (Bosellini, 1968; Rossi, 1969) is 50 to 70 meters thick and consists