The village of Castelmola, in the southern sector of the Peloritani Mountains (Sicily), sits on the summit of an isolated peak that consists of a limestone and dolomite sequence of white-greyish color rocks that occur in thick beds and pass upward into an alternation of lower Liassic marly limestones, belonging to the Taormina Unit. At the base, this passes into sands and red conglomerates of Verrucano facies, which outcrops along the slopes exposed towards the north and east, and which is transgressively superposed upon metamorphic units. Structurally, the succession is affected by deformation which has produced diffuse fracturing of the rock material, subdividing it into elements of variable dimensions as a result of the intersection of tectonic discontinuities and stratigraphic planes. Furthermore, in correspondence with the overlapping planes, intense cataclastic effects are observed that may lead to the complete disintegration of the rock, giving a type of coarse-grained detritus in a sandy matrix. Along the slopes of the Castelmola peak widespread weathering occurs, mainly related to intensely tectonized zones, and there are karstic cavities of various dimensions. This leads to an accentuated anisotropy which influences the mechanical properties of the rock material. Rock masses of huge dimensions have been affected by collapse. This causes great risks to the local population since the road through this area constitutes the only access to the village and provides a connection with Taormina. The most recent collapse (1996) of a significant volume of rock from the NW slope has interrupted the access road and generated a higher hazard due to the lack of support of the rock masses above. Structural analysis, geognostic boreholes and geophysical investigations carried out on the flanks and within the Castelmola peak have allowed us to verify in detail the lithostratigraphic and fracturing conditions of the rock mass, which strongly control its stability. The typologies of possible landslides have been identified, permitting the distinction of three zones of geomechanic homogeneity that qualitatively define their stability conditions
Kinematic analysis of rock falls in an urban area: the case of Castelmola hill near Taormina (Sicily, Italy)
PAPPALARDO, Giovanna
2005-01-01
Abstract
The village of Castelmola, in the southern sector of the Peloritani Mountains (Sicily), sits on the summit of an isolated peak that consists of a limestone and dolomite sequence of white-greyish color rocks that occur in thick beds and pass upward into an alternation of lower Liassic marly limestones, belonging to the Taormina Unit. At the base, this passes into sands and red conglomerates of Verrucano facies, which outcrops along the slopes exposed towards the north and east, and which is transgressively superposed upon metamorphic units. Structurally, the succession is affected by deformation which has produced diffuse fracturing of the rock material, subdividing it into elements of variable dimensions as a result of the intersection of tectonic discontinuities and stratigraphic planes. Furthermore, in correspondence with the overlapping planes, intense cataclastic effects are observed that may lead to the complete disintegration of the rock, giving a type of coarse-grained detritus in a sandy matrix. Along the slopes of the Castelmola peak widespread weathering occurs, mainly related to intensely tectonized zones, and there are karstic cavities of various dimensions. This leads to an accentuated anisotropy which influences the mechanical properties of the rock material. Rock masses of huge dimensions have been affected by collapse. This causes great risks to the local population since the road through this area constitutes the only access to the village and provides a connection with Taormina. The most recent collapse (1996) of a significant volume of rock from the NW slope has interrupted the access road and generated a higher hazard due to the lack of support of the rock masses above. Structural analysis, geognostic boreholes and geophysical investigations carried out on the flanks and within the Castelmola peak have allowed us to verify in detail the lithostratigraphic and fracturing conditions of the rock mass, which strongly control its stability. The typologies of possible landslides have been identified, permitting the distinction of three zones of geomechanic homogeneity that qualitatively define their stability conditionsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
