GNGTS 2013 - Atti del 32° Convegno Nazionale

a recent travertine mound in the Euganean Hydrothermal System, northern Italy. Sedimentology, doi: 10.1111/ sed.12069. Semenza E.; 1974: La fase giudicariense, nel quadro di una nuova ipotesi sull’orogenesi alpine nell’area italo-dinarica . Memorie della Società Geologica Italiana, 13 , 187-226. Serpelloni E., Anzidei M., Baldi P., Casula G. and Galvani A.; 2005: Crustal velocity and strain-rate fields in Italy and surrounding regions: new results from the analysis of permanent and non-permanent GPS networks . Geophysical Journal International, 161 , 861-880. Zampieri D.; 1995: Tertiary extension in the southern Trento Platform, Southern Alps, Italy . Tectonics, 14 , 645-657. Zampieri D., Massironi M., Sedea R. and Sparacino V.; 2003: Strike-slip contractional stepovers in the Southern Alps (northeastern Italy) . Eclogae Geologicae Helvetiae, 96 , 115-123. Zampieri D. and Massironi M.; 2007: Evolution of a poly-deformed relay zone between fault segments in the eastern Southern Alps, Italy . Geological Society London Special Publications, 290 , 351-366. Zanferrari, A., Bollettinari, G., Carobene, L., Carton, A., Carulli, G.B., Castaldini, D., Cavallin, A., Panizza, M., Pellegrini, G.B., Pianetti, F. and Sauro, U.; 1982: Evoluzione neotettonica dell’Italia nordorientale . Memorie di Scienze Geologiche, 35 , 355-376. Zattin M., Cuman A., Fantoni R. Martin S., Scotti P. and Stefani C.; 2006: From Middle Jurassic to Neogene cooling: the thermochronological evolution of the Southern Alps . Tectonophysics, 414 , 191-202. UPPER PLEISTOCENE - HOLOCENE TECTONIC ACTIVITY OF THE M. JOUF-MANIAGO THRUST-SYSTEM (CARNIC PREALPS, NE ITALY) M.E. Poli 1 , G. Monegato 2 1 Dept. of Chemistry, Physics and Environment, University of Udine, Italy 2 Institute of Geosciences and Earth Resources, C.N.R. Torino, Italy Introduction. The study area belongs to the Plio-Quaternary front of the eastern Southalpine Chain (ESC), a SSE verging, WSW-ENE striking fold and thrust belt in evolution from the Middle Miocene to the Present (Fig.1). Up to now the ESC thrust-system accommodates the present 2 mm/y shortening (Serpelloni et al. , 2005) and crustal thickening and propagates towards the Friulian piedmont Plain. The Venetian-Friulian prealpine area is characterized by medium/high seismicity both instrumental and historical. According the DBMI11 (Locati et al. , 2011) many M>6 historical earthquakes hit the Prealpine area: 1117 (Verona), 1348 (Carnia), 1695 (Asolo), 1873 (Belluno), 1936 (Bosco del Cansiglio) and 1976 (Friuli). The DISS3 Catalogue (http://diss.rm.ingv.it/ dissNet/) shows three seismogenetic sources in the investigated area: the Maniago source that is considered responsible for the 07/10/1776 Tramonti earthquake; the Tramonti source linked to the 07/06/1794 earthquake and the Sequals source that is considered a silent source because of no historical earthquakes can be referred to this fault until now (Burrato et al. , 2008). In order to define the upper Pleistocene – Holocene tectonic activity of Southalpine chain in the Carnic Prealps we carried out a morphotectonic analysis of the terraced succession and the related sedimentary units in the lower reach of the Meduna valley. Stratigraphic and structural framework. The structural framework of the investigated area is characterized by the M. Jouf-Maniago thrust-system (JM in Fig. 1) dealing with two arched WSW-ENE striking, SSE-verging thrusts (the Maniago and Mt. Jouf respectively), bordering the prealpine area between Maniago and Forgaria del Friuli, south the Periadriatic thrust (PE in Fig. 1). The JM strongly involves the pre-Quaternary succession that in the study area starts with the Upper Jurassic–Upper Cretaceous Friulian Carbonate Platform that drowned during the Paleogene because of the westward propagation of the front of the External Dinarides. The platform was buried by the Scaglia Rossa Friulana hemipelagic unit and by the thick turbiditic sequence of the Clauzetto Flysch during the Lower Eocene. Starting from the Aquitanian, the Cretaceous and Paleogene formations were unconformably covered by the thick (about 3000 m) Miocene clastic wedge of the eastern Southalpine Chain foredeep (Massari et al. , 1986; Zanferrari et al. , 2008 and references therein). 193 GNGTS 2013 S essione 1.2