GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 1.1 41 The spatial distribution of the fault rocks documented in this study suggests that the largest volumes of loose breccias are located in the overstep sector, where the two major fault strands overlap and where also secondary extensional structures overprint compressive features. Here, the increased structural complexity provides favourable conditions for cataclasite and loose breccia development, thus highlighting the fundamental role of inherited faults and structural complexity in developing anomalous amount of fault rocks along active fault segments. The spatial distribution and the quantitative analysis (e.g. grain size and shape distributions) of cataclastic facies may unravel the deformational processes (seismic vs aseismic) controlling the evolution of active fault zones developed in carbonate platforms. References Collettini C., Viti C., Tesei T., Mollo S.; 2013: Thermal decomposition along natural carbonate faults during earthquakes. Geology., 41, 927-930, DOI 10.1130/G34421.1. Demurtas M., Fondriest M., Balsamo F., Clemenzi L., Storti F., Bistacchi A., Di Toro G.; 2016: Structure of a normal seismogenic fault zone in carbonates: The Vado di Corno Fault, Campo Imperatore, Central Apennines (Italy). Journal of Structural Geology., 90, 185-206, DOI 10.1016/j.jsg.2016.08.004. De Paola N., Hirose T., Mitchell T., Di Toro G., Viti C., Shimamoto T.; 2011: Fault lubrication and earthquake propagation in thermally unstable rocks . Geology, 39, 35-38, DOI 10.1130/G31398.1. Di Toro G., Han R., Hirose T., De Paola N., Nielsen S., Mizoguchi K., Ferri F., Cocco M., Shimamoto T.; 2011: Fault lubrication during earthquakes. Nature., 471, DOI:10.1038/nature09838. Galli P.A.C., Giaccio B., Messina P., Peronace E., Zuppi G.M.; 2011 Palaeoseismology of the L’Aquila faults (central Italy, 2009, Mw 6.3 earthquake): implications for active fault linkage . Geophysical Journal International., 187, 1119-1134, DOI: 10.1111/j.1365-246X.2011.05233.x. Moro M., Falcucci E., Gori S., Saroli M., Galadini F.; 2016: New paleoseismic data across the Mt. Marine Fault between the 2016 Amatrice and 2009 L’Aquila seismic sequences (central Apennines). Annals of geophysics., 59, DOI: 10.4401/ag-7260. Nielsen S.; 2017: From slow to fast faulting: recent challenges in earthquake fault mechanics . Geology., DOI: 10.1098/ rsta.2016.0016. AN INTEGRATED, MULTI-CONSTRAINED AND MULTI-SCALE PICTURE OF THE UPPER CRUSTAL STRUCTURE OF THE IRPINIA ACTIVE FAULTS SYSTEM (SOUTHERN ITALY) G. De Landro 1 , O. Amoroso 1* , G. Russo 1 , R. Esposito 1 , S. Tarantino 1 , A. Zollo 1 , A. Ascione 2 , S. Mazzoli 2 , M. Parente 2 , S. Garambois 3 , J. Virieux 3 , T.A. Stabile 4 , A. Lomax 5 1 Department of Physics, Univ. of Naples, Italy 2 Department of Earth Sciences, Environment and Georesources (DiSTAR), Univ. of Naples, Italy 3 ISTerre, Univ. Grenoble Alpes, Grenoble, France 4 CNR-IMAA, Tito (PZ), Italy 5 Alomax Scientific, Mouans-Sartoux, France * now at Dept. of Physics, Univ. of Salerno, Fisciano (SA), Italy Introduction. This study focuses on the Irpinia fault zone (IFZ), that is a crustal volume embedding the still active fault system that generated the 1980 M6.9 earthquake, the strongest event of the last decades in southern Italy. Hence, the importance of improving the knowledge of the fault system dynamic, especially in terms of earthquake triggering mechanism, by an accurate tracking of the seismicity, the propagation medium’s features and their temporal variation. For this challenging purpose is required a multi-disciplinary analysis, that allow us to interpret in synergy seismological and geological data with different methodologies. The imaging of crustal seismic velocity provides significant constraints on the physical properties of host rocks and on the potential presence of fluids, in particular in the volume