In this area dominated by rock types of pyroclastic material.

The oldest pyroclastic material in the formation is 3 or 4 million years old.

Which brings us on nicely to a discussion of pyroclastic rocks themselves.

The colors of the pyroclastic rocks vary from brown to yellow.

The most devastating effect of volcanic ash comes from pyroclastic flows.

Patrice's group had already calculated areas of high and low pyroclastic hazard.

These hot gases are known as a pyroclastic flow.

In a volcanic eruption, the same thing happens with a pyroclastic flow.

On 24 December 2006, streaks of red from the pyroclastic flows became visible.

It has been spouting bright red pyroclastic deposits of its own.

He was killed on June 3, 1991, when a pyroclastic flow overcame his post.

An estimated 16,000 people died due to hydrothermal pyroclastic flows.

The land is punctuated by pyroclastic cones of Holocene age.

On 25 June 1997, nineteen people died when they were overtaken by a pyroclastic flow.

This volcano is well known for its ash explosions and pyroclastic flows.

However, it is generally less pronounced in the area of pyroclastic flows and deposits.

The total area of recognisable pyroclastic fall was greater than 800,000 km2.

Do you know what a pyroclastic surge is?

"If you're in the path of a pyroclastic flow, that's it.

There are several factors which can produce a pyroclastic flow:

A second eruption on May 16 led to pyroclastic flows that killed another 200 inhabitants.

Lava flows and pyroclastic deposits are found around the volcano.

A pyroclastic flow in 1997 killed three people.

It is believed that Pompeii was destroyed by a pyroclastic flow.

But in 1993, pyroclastic flows killed 75 people, mainly farmers, during the eruption.

Which brings us on nicely to a discussion of pyroclastic rocks themselves.

The colors of the pyroclastic rocks vary from brown to yellow.

About half of the 800-metre-thick basin filling is made of pyroclastic rock.

Its unstable slopes are primarily made of pyroclastic rock.

Generally, the greatest strain intensity is throughout pyroclastic rocks.

Pyroclastic rock is found in this area.

Basaltic tuff or pyroclastic rocks are rare but not unknown.

Welded pyroclastic rocks resist weathering and are therefore easily identified.

The remaining products from Fee's earliest volcanic activity is a minor portion of pyroclastic rock.

Pyroclastic rocks are the product of explosive volcanism.

This confirms that these pyroclastic rocks were not created in pyroclastic flows.

Pyrrhotite is common in associated pyroclastic rock.

Examples of pyroclastic rocks are tuff and ignimbrite.

These pyroclastic rocks give rise to the craggy landscapes typical of the central fells.'

Typically, this eruption column is composed of hot gas, ash and pyroclastic rocks - volcanic material in solid form.

Pyroclastic rocks (tuff) are pyroclastic deposits which have been lithified.

Katmai is a stratovolcano, formed from alternating layers of lava flows and pyroclastic rocks.

In addition felsic pyroclastic rocks are very common in places and one sandstone-conglomerate lava flow can be found.

Pyroclastic rocks may be a range of clast sizes, from the largest agglomerates, to very fine ashes and tuffs.

The first eruptive phase started about four million years ago with the eruption of dacite lava flows and pyroclastic rock.

These volcanic pipes are genetically associated with the rhyolitic, pyroclastic rocks that cover the whole southern part of Antiparos.

Its summit consists of pyroclastic rocks (Schweißschlacken) that form a volcanic crater that is open towards the east.

Slag Hill proper consists of andesite lava flows and small amounts of pyroclastic rock.

Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.