Also found in: Encyclopedia, Wikipedia.
Related to pyroclastic: Pyroclastic rocks


Composed chiefly of rock fragments or particles of volcanic origin, such as pumice, obsidian, or volcanic ash.


(Geological Science) (of rocks) formed from the solid fragments ejected during a volcanic eruption


(ˌpaɪ rəˈklæs tɪk)

composed chiefly of volcanic rock fragments, as agglomerate or tuff.


adj (Geol) rockspyroklastisch; pyroclastic flowpyroklastischer Strom
Mentioned in ?
References in periodicals archive ?
Officials cautioned people near Shinmoedake about the possibility of deadly pyroclastic flows.
People living near these danger areas were advised to observe precautions associated with rockfalls, pyroclastic density currents and ashfall.
It also called for caution against falling volcanic rocks and pyroclastic flows in areas within about 2 km of the crater.
Pyroclastic density currents or PDCs have deposited to the 4.
As of January 30, 2018, about 119 volcanic earthquakes, 68 rockfall events, nine tremor events, two lava fountaining, and two episodes of thick pyroclastic density current (PDC) generation from lava collapse have been recorded and released by PHIVOLCS.
With Alert Level 4 in place, public have been strongly advised to not enter the eight-kilometre danger zone and to be vigilant against pyroclastic currents, lahars and sediment-laden stream flows.
Lava flows in two gullies had advanced down the volcano's slopes more than half a mile and pyroclastic flows - superheated gas and volcanic debris - had spread three miles from the crater in one area, the Philippine Institute of Volcanology and Seismology said.
pyroclastic flows, superheated gas and volcanic debris, had reached 5
On its Facebook page, PHIVLOCS shared videos of lava fountaining and pyroclastic flow from the volcano Monday night, saying the lava reached 500 to 700 meters above the crater rim, and produced an ash plume that was 4 kilometers high.
Authorities warned a violent eruption may occur in hours or days, characterized by more rumblings and pyroclastic flows - superheated gas and volcanic debris that race down the slopes at high speeds, vaporizing everything in their path.
Amateur videos taken on Monday night showed thicker pyroclastic flows, or lava trails, coming from the crater of the active volcano and video from the state volcanalogy institute on Tuesday (January 16) showed thick ash following lava trails flowing down the foot of Mayon.
Li and Milliken find that the most obvious water-bearing exposures occur in broad pyroclastic deposits (involving gas-driven eruptions)--and the biggest, containing up to 500 ppm water, covers the northern half of the Aristarchus Plateau.