Pyroclastic rock which is derived from the collapse of volcanic ash clouds.
The amount of volcanic material, consisting of both pyroclastic material and lava flows, is great.
Igneous rocks, whether lava flows or pyroclastic ejections, are less important in the Quaternary than in the Tertiary, though volcanic activity is known to have continued into the Quaternary.
Pyroclastic density currents.
Pyroclastic fall deposit or had spent the night asleep on the beach!
Pyroclastic flows from an eruption resulted in the first deaths directly caused by the volcano.