The mineralogical and geomechanical properties of a distinctive early Quaternary marine clay unit that underlies the eastern and southern flanks of Mt Etna, which may play a role in gov-erning the style of instability on the edifice, have been determined. Preliminary clay mineral identification revealed the presence of interlayered illite-smectite and disordered kaolinite. The clay is heavily over consolidated (OCR≥32) and is a very stiff, extremely high undrained strength closely fissured, dark yellowish grey silty calcareous CLAY. Direct shear and ring shear tests measured peak shear strength parameters of c΄ = 51 kN/m2 and φ΄ = 20˚ and re-sidual shear strength parameters c΄r = 0 to 3.0 kN/m2 and φ΄r = 6.4 to 9.7˚. The mass strength of the clay will be influenced by the polished fissures, which are close to φ΄r, and may be a controlling factor in the style and rate of movement of the observed flank instability depend-ing on fissure orientation.
|Title of host publication||Geologically Active: Proceedings of the 11th IAEG Congress. Auckland, New Zealand, 5-10 September 2010|
|Pages||323 - 329|
|Publication status||Published - 2010|
|Event||11th IAEG Congress: Geologically Active - Auckland, New Zealand|
Duration: 1 Jan 2010 → …
|Conference||11th IAEG Congress|
|Period||1/01/10 → …|