Conspicuous concentrations of minerals much larger than the grain size in this type of rock are called phenocrysts. Colonnades and entablatures are two structures formed by this type of rock when it exhibits fractures along a vertical plane, giving a hexagonal shape, which is known as columnar jointing and exhibited by Devil's Tower and the Giant's
Conspicuous concentrations of minerals much larger than the grain size in this type of rock are called phenocrysts. Colonnades and entablatures are two structures formed by this type of rock when it exhibits fractures along a vertical plane, giving a hexagonal shape, which is known as columnar jointing and exhibited by Devil's Tower and the Giant's Causeway. Rheomorphism is responsible for layers in this type of rock that differ in composition, texture, or geochemical make-up, which are called (*) "flow bands". The formation of large provinces of it is associated with extinction events. It can form laccoliths, batholiths, and plutons. This type of rock can be extrusive or intrusive, and its most common types are granite and basalt. For 10 points, name this type of rock formed by the cooling of magma or lava.
Conspicuous concentrations of minerals much larger than the grain size in this type of rock are called phenocrysts.