New stratigraphic and biostratigraphic data arising from the
realization of the Sheet No. 405 "Campobasso" of the new Geological map
of Italy (1:50.000 scale - CARG Project) allowed, for the first time in this
area, to stratigraphically and cartographically define all the intervals
composing the basinal Sannio Unit Auct.. Structural analysis and the
chronostratigraphic redefinition of siliciclastic deposits covering the
Sannio Unit and the carbonate platform successions of the Matese-
Frosolone Units, indicate two main evolutionary stages in the Miocene-
Pliocene structuring of this portion of the Southern Apennines. In the
first stage, starting before Serravallian times, E-verging contraction
affected exclusively the basinal units together with their siliciclastic
cover. During the second stage, beginning after early Messinian times,
NE-verging compression involved both the basinal Sannio Unit and the
Matese-Frosolone Units