volcanic pipe

Diamonds are the result of very high heat and pressure in deep volcanic pipes.

However, no source volcanic pipe deposit was apparent.

A volcanic pipe containing diamonds is known as a primary source of diamonds.

The nearby Callander Bay is also a volcanic pipe.

Although not as old as most diamonds, volcanic pipes that cough up the stones are definitely elderly.

A diatreme is a breccia-filled volcanic pipe that was formed by a gaseous explosion.

The volcanic pipe formed by the violent, supersonic eruption of a deep-origin volcano.

Volcanic pipes form as the result of violent eruptions of deep-origin volcanoes.

Volcanic pipes are relatively rare.

Once diamonds have been transported to the surface by magma in a volcanic pipe, they may erode out and be distributed over a large area.

These typically small surface volcanic craters extend downward in formations known as volcanic pipes.

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

At Carrickarede, the ancient volcanic pipe has left dolerite, a tougher rock than basalt, which erodes more slowly.

The volcanic pipe is a diatreme, composed of olivine lamproite, present as tuff and lava.

The youngest rocks are diatremes, referring to breccia-filled volcanic pipes that were formed by gaseous explosions.

There is a low-temperature reservoir of free carbon dioxide below the lake bottom, which seeps into the lake through a volcanic pipe.

Diamond-bearing volcanic pipes are closely related to the oldest, coolest regions of continental crust (cratons).

The Crater of Diamonds volcanic pipe is part of a 95 million-year-old eroded volcano.

Crater of Diamonds State Park is situated over an eroded lamproite volcanic pipe.

Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes.

The magma in volcanic pipes is usually one of two characteristic types, which cool into igneous rock known as either kimberlite or lamproite.

This is a volcanic pipe, a blow hole from the earth's depths up which the molten magma was forced to the surface in the beginning of time.

And in several volcanic pipe entries found archaeological remains of the Guanches, the ancient inhabitants of Tenerife.

Diatremes often breach the surface and produce a tuff cone, a filled relatively shallow crater known as a maar, or other volcanic pipes.

On volcanic islands the sea can enter the caldera and the face of the volcanic pipe can form a steep coastline.