New stratigraphic, geomorphologic and structural data let to delineate the Pliocene - Quaternary activity of the Arba-Ragogna thrust-system that belongs to the front of the eastern Southalpine Chain, a S-SE verging thrust-belt in evolution from middle Miocene to Present. Geometry and kinematic of the Arba-Ragogna thrust-system were recognised both using structural survey and industrial reflection seismic profiles. The system is arranged as a S-SE verging and about WSW-ENE striking imbricate fan of medium to low-angle thrusts. The outermost is the Arba-Ragogna blind thrust. Its long–lasting activity is testified by the angular unconformities between the Upper Miocene, Upper Pliocene and Pleistocene stratigraphic units. A vertical slip rate of about 0.19 mm/a was calculated for the Arba –Ragogna thrust during the last 21000 years. The Arba-Ragogna thrust is one of the seismogenic sources capable to generate earthquakes with M6 in the Veneto-Friuli region, but it cannot be related to historical earthquakes. It indicates that it is one of the “silent” seismogenic source of the eastern Southern Alps.
Geometria, cinematica e attività pliocenico-quaternaria del sistema di sovrascorrimenti Arba-Ragogna (Alpi Meridionali orientali, Italia NE)
POLI, Maria Eliana;
2009-01-01
Abstract
New stratigraphic, geomorphologic and structural data let to delineate the Pliocene - Quaternary activity of the Arba-Ragogna thrust-system that belongs to the front of the eastern Southalpine Chain, a S-SE verging thrust-belt in evolution from middle Miocene to Present. Geometry and kinematic of the Arba-Ragogna thrust-system were recognised both using structural survey and industrial reflection seismic profiles. The system is arranged as a S-SE verging and about WSW-ENE striking imbricate fan of medium to low-angle thrusts. The outermost is the Arba-Ragogna blind thrust. Its long–lasting activity is testified by the angular unconformities between the Upper Miocene, Upper Pliocene and Pleistocene stratigraphic units. A vertical slip rate of about 0.19 mm/a was calculated for the Arba –Ragogna thrust during the last 21000 years. The Arba-Ragogna thrust is one of the seismogenic sources capable to generate earthquakes with M6 in the Veneto-Friuli region, but it cannot be related to historical earthquakes. It indicates that it is one of the “silent” seismogenic source of the eastern Southern Alps.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
