Frost, B Ronald; Barnes, Calvin G.; Collins, William Joseph; Arculus, Richard; Ellis, David; Frost, Carol D.
This geochemical classification of granitic rocks is based upon three variables. These are FeO / (FeO + MgO) = Fe-number [or FeOtot / (FeOtot + MgO) = Fe*], the modified alkali-lime index (MALI) (Na2O + K2O - CaO) and the aluminum saturation index (ASI) [Al/(Ca - 1.67P + Na + K)]. The Fe-number (or Fe*) distinguishes ferroan granitoids, which manifest strong iron enrichment, from magnesian granitoids, which do not. The ferroan and magnesian granitoids can further be classified into alkalic,...[Show more]
Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.