Volcanic Soil

According to [DINENISO14688:2001], volcanic soil is defined as “magma that has been emitted into the atmosphere during intense volcanic eruptions and, over time has formed deposits; e.g. pumice, scoria, ash”.

The main percentages of volcanic soils are designated and described according to their particle size, structure and colour (Table).

Table: 
Designation and description of volcanic types of soil [DINENISO14688:2001]
Designation Particle Size [in (mm)] Description
Bombs > 2.5 (63) -
Lapilli Pumice > 0.08 (2.0) < 2.5 (63) Particles are blistered and white
Scoria   Particles are blistered and black
Ash Volcanic Sand ≤ 0.08 (2.0) Depending on the region, the soil shows different geotechnical characteristics
Tuff Usually, the soil has local designations.