Hydrothermally altered rhyolite pyroclastic rock from the area of the exposed cryptodome including a chalcedonic veinlet with finely disseminated marcasite in the far-right piece (above scribe end ...

Pyroclastic flows occur when volcanic rock, ash and hot gases surge from volcanoes, often following some kind of tremor or disturbance.

On June 2, at around 11:20 a.m. local time, a giant, superhot avalanche of ash, known as a pyroclastic flow, suddenly exploded from near Mount Etna's summit and raced down its western flank.

The most recent pyroclastic flows with significant reach were recorded on Feb. 10, 2022, Oct. 23, 2021, Dec. 13, 2020, and Feb. 11, 2014, Marco Viccaro, president of Italy’s national volcanology ...

Bereaved families and others held a moment of silence at 4:08 p.m. -- the time the pyroclastic flow created by a violent eruption hit the area 34 years ago -- at the Kitakamikoba farming training ...

The government agency wrote in a translated post that a pyroclastic flow, a combination of ash, rock, and gas, "probably produced by the collapse of material from the northern side of the ...