Search results
Results From The WOW.Com Content Network
Volcanic glass is the amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass , it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disordered array of liquid . [ 1 ]
Basalt, which is highly concentrated in the Earth's oceanic crust, is formed when magma reaches the Earth's surface and cools down at a very fast rate. [1] When magma cools, different minerals crystallize at different times depending on the cooling temperature of that respective mineral.
Schematic diagrams showing the principles behind fractional crystallisation in a magma. While cooling, the magma evolves in composition because different minerals crystallize from the melt. 1: olivine crystallizes; 2: olivine and pyroxene crystallize; 3: pyroxene and plagioclase crystallize; 4: plagioclase crystallizes.
Magma can be found in the mantle or molten crust. Magma (from Ancient Greek μάγμα (mágma) 'thick unguent') [1] is the molten or semi-molten natural material from which all igneous rocks are formed. [2]
However, the rate of magma production in tectonic settings that produce supervolcanoes is quite low, around 0.002 km 3 year −1, so that accumulation of sufficient magma for a supereruption takes 10 5 to 10 6 years. This raises the question of why the buoyant silicic magma does not break through to the surface more frequently in relatively ...
Rhyolite is an extrusive igneous rock, formed from magma rich in silica that is extruded from a volcanic vent to cool quickly on the surface rather than slowly in the subsurface. It is generally light in color due to its low content of mafic minerals, and it is typically very fine-grained ( aphanitic ) or glassy .
Because of their greater thickness, which slows the cooling rate, the rock of laccoliths is usually coarser-grained than the rock of sills. [ 5 ] The growth of laccoliths can take as little as a few months when associated with a single magma injection event, [ 10 ] [ 11 ] or up to hundreds or thousands of years by multiple magmatic pulses ...
In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. The sequence of (usually increasingly silicic) magmas produced by igneous differentiation is known as a magma series.