FORCELLA F. & SAURO U.
Evoluzione morfotettonica del settore meridionale della dorsale del Monte Baldo (Prealpi Venete) – Morphotectonic evolution of the southern sector of the Mt. Baldo chain (Venetian Prealps, Italy)
Pages 83-87
Abstract
The morphostructural evolution of an area bdonging to the southeastern sector of the Giudicarie beh (Mt. Baldo chain, Venetian Prealps, Southcrn Aips) is here examined. The geological structure of this beh is the consequence of Late Miocene tectonics charactcrized by thrust faulting toward ESE. Ridges and valleys sho\V NNE-SSW direction; the ridges have a homocline structure dipping to the west and are delimited toward thc cast by tcctonic scarps, which form the right slope of large asymmetrical valleys. Frequcnt sudace evidences of neolectonic activity are ribbonlike fault scarps, dipping eastward as well as westward, that affect the major slopes. In the southern sector of the Monte Baldo chain the neotectonic activity is particularly evident. h is characterized by collapse surfaces or scarps that prevailingly djp eastward and witness a supcrficiaI gravity tectonics with mass transport in that direction. The most imposing scarps crop out ncar the summit of the ridge where a karst topography, characterized by high density of dolines, is cut and displaced. One of the scarps suikes parallel to the «ridges of Naole» splitting the ridge itsdf. The intermediate furrow is some 30-50 mdeep and runs parallel to the ridges for a few kilometers. Near its base a ribbon Iike scarplet, 1-1,5 m height, testify a recent, probably Holocene, episode of surface faulting. The southeastern slope of the main ridge is characterizcd by a complex pattern of uphill – and downhiJI – facing scarps as \Vdl as by patterns of concentric scars that support thc hypothesis of detachment of large rock bodies. Do\Vnslope, wide outcrops of «syntectonic brecciasl> (senstt Coz· ZAGLIO, 1933) further strengthen the image of active sIope tectonics. It represents the superficia! expression of a regional compressive tectonics still in progress in the Giudicarie belt as it is independently suggested by seismotectonic data.