Lavas

They are (or were) the hottest lavas, and probably more fluid than common mafic lavas.

So, the recent volcanic eruptions from these Hawaiian volcanoes offer a promising glimpse of how lavas erupted from Brushy Butte Volcano may have occurred and how long it might have taken.

Evidence near the summit shows light coloured granite (which had cooled in subterranean chambers several kilometres beneath the surface) lies among dark basaltic lavas (that only form on the surface).

Fertile soils from weathered volcanic lavas have made it possible to sustain dense populations in the agriculturally productive highland areas.

Here basaltic lavas gently flow out of rifts to build huge dome-shaped volcanic mountains whose eroded summits form island arcs, chains, and clusters.

In most cases, the lavas are normally laid down over several million years.

Its lavas are the hottest known anywhere in the solar system, with temperatures exceeding 1,800 K (1,500 °C).

These gold-bearing rocks had furthermore been covered by a thick layer of Ventersdorp lavas and the Transvaal Supergroup of rocks before the meteor struck.

Thus small grains of quartz in a shale are lost or blend with the surrounding particles of clay, and the fine ground-mass of lavas is entirely reconstructed.

Viscous lavas tend to form stratovolcanoes or lava domes.

Volcanic ashes and lavas accumulate on the surface, and igneous intrusions enter from below.

Water and other volatiles can more easily and gradually escape from mafic lava, so eruptions of volcanoes made of mafic lavas are less explosively violent than felsic-lava eruptions.