Tectonic history of the Lagonegro Domain and Southern Apennine thrust belt evolution

Abstract

The tectonic history of the Lagonegro Domain in Southern Italy is an intriguing topic for the Mesozoic Mediterranean paleogeography and is important for reconstructions of the Tethys. Previous interpretations postulate the paleogeographic position of a deep Lagonegro-Molise-(Sicilide) basinal domain between the external Apulia carbonate platform to the east, and the internal Apenninic carbonate platform (i.e. the Alburno-Cervati-Maddalena Mountains) to the west. A second and separate deep basin more to the west was the home of the Liguride units which cover extensive areas of the Southern Apennines. Following an extensive review of previously published concepts and on the base of the structural interpretation of the Southern Apennines thrust belt using additional subsurface data and extensive field mapping, the authors now suggest that all deep basinal units of the Southern Apennines, i.e. the Ligurides, the Lagonegro units and the Molise-Sicilide units, derive from internal areas located to the west with respect to a coeval wide carbonate platform-slope-shallow-basin complex which, in its pre-Middle Miocene reconstruction, extended from Apulia well beyond the present-day Tyrrhenian coast of Southern Italy. The basinal units were first assembled as an accretionary wedge and overthrusted during the Late Miocene over the carbonate platform-slope-shallow-basin complex. The Liguride-Lagonegro-Molise-(Sicilide) accretionary wedge was later cut by an envelopment thrust which overthrust the previously underlying platform complex over the previously emplaced complex accretionary wedge. Our hypothesis in part revives an old concept proposed by Selli (1962) and requires further testing and research. We conclude that paleogeographic reconstructions of the Southern Apennines and the Mediterranean Tethys are still in a state of flux.