Strombolian scoria fall deposit, Bandera, New Mexico Basaltic scoria is the typical product of strombolian activity. Cindery in appearance, scoria fragments have a light, frothy texture.
Individual clasts are sharp-edged and angular.
Normally, basaltic scoria is a greyish-black colour, but when fresh it may be stunningly iridescent, shining in peacock blue colours. Because the lava is easily fragmented by escaping gas, only a small proportion of the finest grained material is produced, so a typical scoria deposit is not dusty. Most fragments here near the Bandera cone in New Mexico are 1-3 cm in diameter. About 0.01 cubic kilometers of magma was erupted, and the eruption column probably did not reach more than a few hundred meters above the vent. Thus the deposit thins rapidly away from the vent.