Formation
Rapakivi granites have formation ages from Archean to recent and are not usually associated with orogeny. They have formed in shallow (a few km deep) sills of up to 10 km thickness.
Rapakivi granites are often found associated with intrusions of anorthosite, norite, charnockite and mangerite. It has been suggested that the entire suite results from the fractional crystallization of a single parental magma .
Read more about this topic: Rapakivi Granite
Famous quotes containing the word formation:
“The moral virtues, then, are produced in us neither by nature nor against nature. Nature, indeed, prepares in us the ground for their reception, but their complete formation is the product of habit.”
—Aristotle (384–322 B.C.)
“Out of my discomforts, which were small enough, grew one thing for which I have all my life been grateful—the formation of fixed habits of work.”
—Elizabeth Stuart Phelps (1844–1911)
“It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organisation upon the natural organisation of the body.”
—Thomas Henry Huxley (1825–1895)