The Miocene vertebrate-bearing deposits of Scontrone (Abruzzo, Central Italy). Stratigraphic and paleoenvironmental analysis

The Miocene carbonate deposits of Scontrone (Abruzzo, Central Italy) are well-known among palaeontologists because of their fossil vertebrate content that exhibits striking similarities to those of the remarkable “Terre Rosse” faunal complex of the Gargano region, defining the existence of the Miocene Central Mediterranean Apulia paleobioprovince. The main goal of this paper is to establish age and environment of the Scontrone vertebrate bonebeds. The vertebrate remains are embedded in the basal portion of the Lithothamnion Limestone, a widespread carbonate-ramp lithosome representative of the Tortonian-early Messinian transgression over the entire Apulia Platform. The bonebeds belong to marginal-marine deposits (here called “Scontrone calcarenites”) preserved in a small area below transgressive ravinement surfaces. The rapid vertical and lateral facies variations displayed by the “Scontrone calcarenites”, together with paleoenvironmental considerations deriving from the vertebrate association document a complex wave-dominated river-mouth depositional setting developed over a large, flat and semi-arid carbonate ramp. The “Scontrone calcarenites” have been split herein into five facies associations (intervals a-e) representing the stratigraphic response to a discontinuous or punctuated transgression within an overall rise of the relative sea level. Because of the absence of age-diagnostic fossils, the age of the “Scontrone calcarenites” cannot be directly defined through their paleontological content. However, a regional stratigraphic correlation between the Lithothamnion Limestone of Scontrone and the Lithothamnion Limestone of northern Majella, which is biostratigraphically well constrained, allowed the attribution of the “Scontrone calcarenites” to the Tortonian.