Tectono-sedimentary evolution of the Pliocene toLower Pleistocene succession of the Apricena-Lesina-Poggio Imperiale quarrying district (western Gargano, southern Italy)

The post-Miocene marine succession of the «Apricena horst» isdescribed with the purpose to verify the chronostratigraphic constraintsfor the type-locality of the Pirro Nord Faunal Unit. Thestratigraphic succession has been subdivided in four units boundedby ubiquitous unconformities with evidence of subaerial exposure.The two basal units (dated late Zanclean to at most early Piacenzian)are formally grouped in the Lago di Varano Fm. that on the wholeconsists of sediments ranging from lagoonal to circalittoral environments.Within the lowermost unit, a megabreccia is interpreted asthe product of a tsunami event. The third unit, Gelasian in age, isinformally cited as Calcari a Briozoi Fm. The last unit, the LowerPleistocene Serracapriola Fm., consists of siliciclastic deltaic sedimentsand represents the closure of the marine cycle. Conspicuouslateral facies and thickness changes, and the frequency of unconformitiesare the consequence of an intense synsedimentary tectonicactivity developed in the frame of the southern Apulia foredeep closure.In the study area, such activity is documented by two E-Wtrending normal faults which, during Zanclean and at least the earliestGelasian, controlled the Pliocene horst-graben system of theApricena-Poggio Imperiale area.