A-type granites: geochemical characteristics, discrimination and petrogenesis

  title={A-type granites: geochemical characteristics, discrimination and petrogenesis},
  author={Joseph Bruce Whalen and Karen L. Currie and Bruce W. Chappell},
  journal={Contributions to Mineralogy and Petrology},
New analyses of 131 samples of A-type (alkaline or anorogenic) granites substantiate previously recognized chemical features, namely high SiO2, Na2O+K2O, Fe/Mg, Ga/Al, Zr, Nb, Ga, Y and Ce, and low CaO and Sr. Good discrimination can be obtained between A-type granites and most orogenic granites (M-, I and S-types) on plots employing Ga/Al, various major element ratios and Y, Ce, Nb and Zr. These discrimination diagrams are thought to be relatively insensitive to moderate degrees of alteration… 
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