Rock types | General lithology | Susceptibility | Representative groups |
Rock of any type, sedimentary or crystalline Rigid soils with a thickness of less than 60 m to the rocky base, as long as the upper strata are composed of stable deposits of sand, gravel or hard clay | Impervious limestones, basalts, andesites, low degree of weathering, little fracturing, rocks with high resistance to shear, low groundwater level. | Very high (0.76 - 1) | Basalts, diabases, gabbro |
Andesite, diorite, porphyry, granites | |||
Serpentinite, riodacite, rhyolite, marbles, compact limestones | |||
Stable deposits of non-cohesive soils or hard clays when their depth to the rocky base exceeds 60 m and the upper strata are composed of sands, gravels or hard clays | High degree of weathering of the above mentioned rocks and massive clastic sedimentary rocks, low resistance to shear, shear fracture. | high (0.51 - 0.75) | Permeable limestones, |
Schists, clastic metamorphites, fissured igneous | |||
Gaps and compact conglomerates, cohesive sandstones | |||
Deposits of soft or medium clays and sands with thicknesses of 10 m or more with or without the presence of intermediate layers of sand or other non-cohesive soils | Poorly consolidated rocks or soils, considerable weathering of sedimentary, intrusive and volcanic rocks, fluctuations in the water table. | Moderate (0.26 - 0.5) | Vulcanogenic-sedimentary rocks |
Compact clays | |||
Massive clayey rocks with jointing, jointed conglomerates with medium cohesion | |||
Clay and soft sand deposits with thicknesses greater than 12 m | Quaternary unconsolidated soils, clay fill, unconsolidated pyroclastic and fluvio-lacustrine soils, surface water tables. | Come down (0 - 0.25) | Marls, silts, sandstones |
Sandy clay soils, | |||
Marsh, fluvial-lacustrine, alluvial deposits |