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International audience; 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 14 C 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 GSA Bulletin; Month/Month 2017; v. 129; no. intermontane basins become progressively younger from the Tyrrhenian toward the Adriatic side of the central Apennines is rejected. In the northern and central Apen-nines, only two major syndepositional ex-tensional 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 exten-sional 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.

Freshwater ostracod assemblages from San Demetrio Synthem (L’Aquila Basin, central Apennines, Italy), dating back to the late PiacenzianGelasian, are studied. Six genera and eight species are recognised, six of which are new: Caspiocypris amiterni Spadi & Gliozzi sp. nov., C. bosii Spadi & Gliozzi sp. nov., C. nicandroi Spadi & Gliozzi sp. nov., C. vestinae Spadi & Gliozzi sp. nov., Cypria bikeratia Spadi & Gliozzi sp. nov., and Ilyocypris ilae Spadi & Gliozzi sp. nov. Additionally, one fragmentary valve referred to Paralimnocythere cf. P. dictyonalis Medici, Ceci & Gliozzi, 2011, one valve ascribed to Amnicythere ex gr. stanchevae Krstic, 1975, one fragment tentatively identified as Limnocythere? sp. and four poorly preserved valves of Cypridoidea indet. were also recovered. The genus Caspiocypris is revised, and an emended diagnosis is provided. Comparisons are made with the most similar co-generic species occurring in the Neogeneof Italy and the Paratethyan domain. The ostracod fauna of the San Demetrio Synthem shows the greatest affinity at the generic level with the Pontian (MessinianZanclean) ostracods of the Pannonic, Dacic and Euxinic Basins. To explain thisaffinity, two hypotheses are discussed: (1) passive dispersal of Paratethyan forms into the Italian PlioPleistocene palaeolakes; and (2) endemic evolution of several species in different PlioPleistocene palaeolakes from the Paratethyan likelate Messinian Lago-Mare ostracod fauna of the Palaeomediterranean area.

We present the geological map at 1:25,000 scale of the Plio-Quaternary Paganica-San Demetrio-Castelnuovo Basin corresponding to the epicentral area of the 6 April 2009 Mw: 6.29 L’Aquila earthquake. The map focuses on the relationships between the active tectonics and the Plio-Quaternary deposits and on the early evolution of this continental basin. Fine-scale geological field surveys, coupled with paleontological data, facies analyses, well logs and geophysical data interpretation, allowed to better understand the stratigraphy and to review the previously described stratigraphical units, resulting in the definition of eight synthems, spanning from late Piacenzian to Holocene. More precisely, the occurrence of a Caspiocypris species flock (ostracods) at the base of the sedimentary infill of the basin formed by a lacustrine system, suggests that the onset of deposition started in the late Piacenzian. The lacustrine system disappeared around the Gelasian/Calabrian transition, while the subsequent evolution of the sedimentary basin was characterized by the presence of fluvial and alluvial fan systems progressively entrenched into the lake deposits. The results of the above-mentioned activities are summarized in the attached geological map, where the Plio-Quaternary synthems and the active normal faults accountable for the significant seismicity were highlighted.

Work on thermal pools at Poggetti Vecchi in Grosseto, Italy, exposed an up to 3-meter-thick succession of seven sedimentary units. Unit 2 in the lower portion of the succession contained vertebrate bones, mostly of the straight-tusked elephant, Palaeoloxodon antiquus, commingled with stone, bone, and wooden tools. Thermal carbonates overlying Unit 2 are radiometrically dated to the latter part of the middle Pleistocene. This time span indicates that early Neanderthals produced the human artifacts from Poggetti Vecchi. The elephant bones belong to seven individuals of different ages. Sedimentary facies analysis and paleoecological evidence suggest a narrow lacustrine-palustrine embayment affected by water-level fluctuations and, at times, by hydrothermal water. Cyclic lake-level variations were predominantly forced by the rapid climatic fluctuations that occurred at Marine Isotope Stage (MIS) 6–7 transition and throughout the MIS 6. Possibly an abrupt, intense, and protracted cold episode during the onset of MIS 6 led to the sudden death of the elephants, which formed an unexpected food resource for the humans of the area. The Poggetti Vecchi site adds new information on the behavioral plasticity and food procurement strategies that early Neanderthals were able to develop in Italy during the middle to the late Pleistocene transition.

The Tiberino Basin is a wide Plio–Pleistocene intermountain basin located in central Apennine (central Italy). Its sedimentary infill is made of a thick succession of Pliocene–early Quaternary continental deposits, the oldest of which can be referred to the Fosso Bianco Formation, composed of grey clays deposited in a huge (at least 500 km2) and relatively deep (not less than 50 m) lake, the Palaeolake Tiberino. We analyse the lacustrine ostracod assemblages from the Fosso Bianco Formation and provide descriptions of five new species included in the subfamily Candoninae (Caspiocypris basilicii sp. nov., Caspiocypris perusia sp. nov., Caspiocypris posteroacuta sp. nov., Caspiocypris tiberina sp. nov. and Caspiocypris tuderis sp. nov.)) and one new species included in the subfamily Limnocytherinae (Paralimnocythere umbra sp. nov.)). The five species of Caspiocypris seem to represent a species flock, i.e. Caspiocypris includes a group of closely related species characterized by monophyly, endemism and speciosity, confirming the ‘ancient lake’ nature of the Palaeolake Tiberino during the Piacenzian–Gelasian. The ostracod assemblage points to a relatively deep-water and low energy lacustrine environment marked by a high level of endemism.