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Freshwater ostracod assemblages from San Demetrio Synthem (L'Aquila Basin, central Apennines, Italy), dating back to the late Piacenzian–Gelasian, are studied. Six genera and eight species are recognised, six of which are new:Caspiocypris amiterniSpadi & Gliozzi sp. nov.,C. bosiiSpadi & Gliozzi sp. nov.,C. nicandroiSpadi & Gliozzi sp. nov.,C. vestinaeSpadi & Gliozzi sp. nov.,Cypria bikeratiaSpadi & Gliozzi sp. nov., andIlyocypris ilaeSpadi & Gliozzi sp. nov. Additionally, one fragmentary valve referred toParalimnocytherecf.P. dictyonalisMedici, Ceci & Gliozzi, 2011, one valve ascribed toAmnicythereex gr.stanchevaeKrstić, 1975, one fragment tentatively identified asLimnocythere? sp. and four poorly preserved valves of Cypridoidea indet. were also recovered. The genusCaspiocyprisis revised, and an emended diagnosis is provided. Comparisons are made with the most similar co-generic species occurring in the Neogene of Italy and the Paratethyan domain. The ostracod fauna of the San Demetrio Synthem shows the greatest affinity at the generic level with the Pontian (Messinian–Zanclean) ostracods of the Pannonic, Dacic and Euxinic Basins. To explain this affinity, two hypotheses are discussed: (1) passive dispersal of Paratethyan forms into the Italian Plio–Pleistocene palaeolakes; and (2) endemic evolution of several species in different Plio–Pleistocene palaeolakes from the Paratethyan-like late Messinian Lago-Mare ostracod fauna of the Palaeomediterranean area. http://zoobank.org/urn:lsid:zoobank.org:pub:881D73C7-E62E-460A-A465-363DAE20A8D5 [ABSTRACT FROM PUBLISHER]

Study of the tectonically active L'Aquila Basin offers new insights into both the creation of the extensional intermontane basins of the central Apennines of Italy and their tectono-sedimentary evolution through time. The combination of large mammal remains, ostracods, molluscs, Mousterian tools, and 14C dating allows better definition of the onset and stratigraphic evolution of the L'Aquila Basin. Interpretation of a seismic reflection profile and well-log data allow evaluation of the subsurface setting of this sedimentary basin and its tectono-sedimentary evolution. The occurrence of a wedge-shaped seismic unit at the base of the basin sedimentary succession defines the first phase of basin fill during a late Piacenzian-Gelasian synrift stage. Activity along the main fault of the extensional fault system responsible for the onset and subsequent development of the western sector of the L'Aquila Basin (L'Aquila-Scoppito subbasin) migrated from southwest to northeast, reaching the presently active Mount Pettino normal fault only in the late Pleistocene-Holocene. The onset of sedimentation in the L'Aquila Basin was synchronous with the onset in the Tiberino Basin, and so the idea that these extensional intermontane basins become progressively younger from the Tyrrhenian toward the Adriatic side of the central Apennines is rejected. In the northern and central Apennines, only two major syndepositional extensional domains can be recognized: a late Miocene rifting area, which includes all the late Miocene extensional basins in Tuscany, and a late Pliocene to earliest Pleistocene rifting area, which possibly includes all the intermontane basins from the Tiberino Basin to the Sulmona Basin. The different time gaps between compressional and extensional deformation at any given locality in the central Apennines could indicate a partial decoupling of processes responsible for the migration of shortening and extension toward the foreland. Diachroneity between the eastward migration of shortening in the foreland and extension in the inner part of the orogen supports the notion that the central Apennines were created as a result of a partially decoupled collision zone. Study of the onset of the central Apennine extensional intermontane basins, together with their seismic activity, indicates that the central Apennine postorogenic extensional domain represents an archive of ~3 m.y. of continued crustal extension. These findings help to refine models of the long-term extensional rate of the central Apennines, and they provide a basis for more reliable seismotectonic models for one of the most seismically active sectors of the central Mediterranean area. [ABSTRACT FROM AUTHOR]

In this paper we inferred the origin of a huge clastic deposit (i.e. L'Aquila Breccia) which widely crops out within the L'Aquila intermontane basin, a tectonic depression in central Apennines, that is bounded by seismogenic active faults, as demonstrated by the earthquake occurred on April 6, 2009 (Mw 6.1). The genesis of this deposit is still debated in the literature: for this reason, a number of methods have been applied, mainly aimed at evidencing its geomorphological and sedimentological features, as well as at defining its geometry and volume through cross sections constrained by borehole data and field observations. On the basis of the obtained results, we identified such deposit as resulting from a Quaternary rock avalanche event. In particular, the rock avalanche would have detached during the cold climate phases of late Middle Pleistocene from the southern slope of the Gran Sasso Range, a sector characterized by the presence of numerous DGSD-related landforms. We performed morphometric analyses of the Gran Sasso slope, in order to define the potential source area of the inferred rock avalanche and, according to the results, the volume estimated from this area (about 108 m3) is coherent with the volume calculated for the preserved rock avalanche deposit. Furthermore, we analyzed the main features of the deposit (i.e. age and morphometric parameters) also in the light of similar rock avalanche events occurred in the same region during the Quaternary, with the aim of discussing potential analogues and better understanding the role of gravity-induced processes in the Quaternary morpho-evolution of the Apennine chain. Unlabelled Image [ABSTRACT FROM AUTHOR]