Genesis
Carbonatites are rare, peculiar igneous rocks formed by unusual processes and from unusual source rocks. Three models of their formation exist:
- direct generation by very low degree partial melts in the mantle and melt differentiation
- liquid immiscibility between a carbonate melt and a silicate melt
- peculiar, extreme crystal fractionation
Evidence for each process exists, but the key is that these are unusual phenomena. Historically, carbonatites were thought to form by melting of limestone or marble by intrusion of magma but geochemical and mineralogical data discount this.
Read more about this topic: Carbonatite
Famous quotes containing the word genesis:
“If only he would not pity us so much,
Weaken our fate, relieve us of woe both great
And small, a constant fellow of destiny,
A too, too human god, self-pity’s kin
And uncourageous genesis . . .”
—Wallace Stevens (1879–1955)
“Behold I have given you every herb bearing seed which is upon the face of all the earth, and every tree, in which is the fruit of a tree yielding seed; to you it shall be for meat.”
—Bible: Hebrew Genesis 1:29.
But in a later context, God told the disgraced Adam, “and thou shalt eat the herb of the field” (Genesis 3:18)
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—Ralph Waldo Emerson (1803–1882)