Granites Flashcards
From what are S-type granites derived?
Sedimentary crustal rock
What are S-type granites depleted in and why?
They are depleted in calcium and sodium due to chemical weathering.
How are sediments made available?
Continent-continent collisions
Describe the aluminium content of S-type granites.
Al-rich, they are peraluminous.
Give three examples of minerals found in S-type granites.
Muscovite, tourmaline, and cordierite.
From what are I-type granites derived?
Igneous crustal rocks
Give an example of where igneous crustal rocks can be found.
Continental margins, e.g. the Andes
Describe the aluminium content of I-type granites.
Al-intermediate, they are metaluminous.
Give two examples of minerals found in I-type granites.
Hornblende and biotite.
From what are A-type granites derived?
Low crustal rocks (dry conditions)
Where type of settings and events are low crustal rocks found?
Intraplate settings, during mountain building and collapse.
Describe the aluminium content of A-type granites.
Al-poor
Describe the alkaline content of A-type granites.
Alkali-rich, they are peralkaline
Describe the composition of A-type granites.
K feldspar-rich, quartz poor
