Volcanic Ultramafic Rocks
Volcanic ultramafic rocks are rare outside of the Archaean and are essentially restricted to the Neoproterozoic or earlier, although some boninite lavas currently erupted within back-arc basins (Manus Trough, New Guinea) verge on being ultramafic. Subvolcanic ultramafic rocks and dykes persist longer, but are also rare. Many of the lavas being produced on Io may be ultramafic, as evidenced by their temperatures which are higher than terrestrial mafic eruptions.
Examples include komatiite and picritic basalt. Komatiites can be host to ore deposits of nickel.
Read more about this topic: Ultramafic Rock
Famous quotes containing the words volcanic and/or rocks:
“Pity the planet, all joy gone
from this sweet volcanic cone;”
—Robert Lowell (1917–1977)
“We envy not the warmer clime, that lies
In ten degrees of more indulgent skies,
Nor at the coarseness of our heaven repine,
Though o’er our heads the frozen Pleiads shine:
‘Tis Liberty that crowns Britannia’s Isle,
And makes her barren rocks and her bleak mountains smile.”
—Joseph Addison (1672–1719)