how was it formed, what type of rock is it and what are the minerals which compose it?
2007-07-22 03:08:07 · 3 answers · asked by shaqy 1 in Science & Mathematics ➔ Earth Sciences & Geology
Tonalite is essentially diorite with more than 10% quartz in the rock.
2007-07-22 03:57:51 · answer #1 · answered by Amphibolite 7 · 2⤊ 0⤋
"Mountaingym" has it right. Tonalite is derived by the usual Bowen's Reaction Series fractional crystallization processes, but from a slightly more silica-rich magma which cools a tad faster than it would if it were to proceed to true "granite". It is dioritic (andesitic) in composition and is therefore more common to convergent plate margins (like K>O, and K>K margins).
Hope this helps.
2007-07-22 11:27:33 · answer #2 · answered by stevenB 4 · 3⤊ 0⤋
According to Wikipedia, "Tonalite is an igneous, plutonic (intrusive) rock, of felsic composition, with phaneritic texture."
2007-07-22 10:47:05 · answer #3 · answered by mechnginear 5 · 0⤊ 0⤋