Which of the following is NOT considered to be a pyroclastic material?

ash

lapilli

cinders

pahoehoe

One of the following that is NOT considered to be a pyroclastic material is;

D. Pahoehoe

Pyroclast material range in size from very small pieces of dust to ash to lapilli to bombs and block to cinders. A pahoehoe is just basaltic lava forming smooth undulating masses. Thus, it is not considered of pyroclastic material.

Answer: (D) PahoehoeExplanation:

Pahoehoe lava flows are described by smooth, lightly undulating, or broadly hummocky surfaces. The liquid lava running beneath a thin, still-plastic crust drags and twists it into tapestry-like folds and rolls relating twisted rope. Pahoehoe lava flows are maintained substantially wholly internally by rivers of liquid lava flowing beneath a fixed or partly solidified surface.