The interplay of structural pathway and weathering intensity in forming mass-wasting processes in deeply weathered gneissic rocks (Sila Massif, Calabria, Italy)

Abstract

This paper presents a detailed map (Main Map) showing geology, tectonics, weathering intensity and spatial distribution of landslides in the San Pietro in Guarano study area (about 7.5 km 2 ), located in the north-western sector of Calabria (southern Italy). In this area, deeply weathered high-grade metamorphic rocks and different types/categories of mass movements are widespread. The Main Map, at 1:5000 scale, results from the combination of information gathered via analysis and interpretation of aerial photographs at different times and scales, multi-temporal geostructural and geomorphological surveys, field investigations and mapping of weathering grade in outcropthrough observation of geologically distinctive characteristics and qualitative and semi-quantitative engineering geological testsintegrated by means of the analysis of both weathering profiles on cutslopes and boreholes logs. The Main Map can represent a useful tool for authorities in charge of land-use planning and can profitably concur to typify landslides and to assess quantitative landslide risk.

Insights on the Origin of Vitrified Rocks from Serravuda, Acri (Italy): Rock Fulgurite or Anthropogenic Activity?

“…The effects of weathering in a Mediterranean climate on the mineralogy and microfabric of granitic and metamorphic rocks from the Sila Massif, Calabria, Southern Italy has been documented [6][7][8][9]. Medium-to-high-grade metamorphic and plutonic rocks were deeply weathered under the late Miocene (Sila Massif emerging time) to the present time [6,10]. The high content of amorphous in SE 3, SE 5, SE 8, SE 9, SE 10, SE 14, and SE 15 (Table 2) confirms that the samples were subjected to chemical decomposition due to weathering effects.…”

A refinement analysis of the shallow landslides susceptibility at regional scale supported by GIS-aided geo-database

“…Due to the complex tectonic history of the Calabrian Arc, outcropping lithologies show different levels of fragmentation and deformation; in particular, the crystalline-metamorphic rocks are pervasively fractured (i.e. cross-cut by a complex fracture pattern related to regional and local-scale faults and fault zones developed during ancient and recent tectonic phases) and affected by intense and deep weathering processes, which produced a disintegration of the rock masses and a thick saprolite horizons, with depths up to 100 m (Cascini et al 1992;Le Pera and Sorriso-Valvo 2000;Calcaterra and Parise 2010;Borrelli, Critelli et al 2012;Borrelli, Perri et al 2014;Borrelli et al 2016;Biondino et al 2018;Ietto et al 2018).…”

Small-scale analysis to rank municipalities requiring slow-moving landslide risk mitigation measures: the case study of the Calabria region (southern Italy)

“…Owing to the complex geodynamic history of Calabria, linked to several tectonic phases (Tortorici et al 1995;Tripodi et al 2018;Van Dijk et al 2000), the outcropping lithological units generally show physical and chemical weathering as well as high levels of fragmentation and deformation, which play an important role in the evolution of hillslopes (Biondino et al 2018;Borrelli et al 2015;Scarciglia et al 2005Scarciglia et al , 2016. Furthermore, the distribution and mechanical behaviour of the lithological units influence the slope dynamics and the nature of geomorphic processes (Sorriso-Valvo 1993).…”