Afm Diagram. A alkali sodium and potassium oxides f iron oxides m magnesium oxide bt tholeiitic basalt fb ferro basalt abt tholeiitic basaltic andesite at tholeiitic andesite d dacite r rhyolite b. Dashed line boundary between tholeiitic and calc alkaline compositions.
Afm diagram showing the relative proportions of the oxides of alkalis a iron f and magnesium m with arrows showing the compositional change path of the magmas in the tholeiitic and the calc alkaline magma series bt tholeiitic basalt fb ferro basalt abt tholeiitic basaltic andesite at tholeiitic andesite d dacite r rhyolite b basalt ab basaltic andesite a andesite. Afm diagram showing the distinction between selected tholeiitic rocks from iceland the mid atlantic ridge the columbia river basalts and hawaii solid circles plus the calc alkaline rocks of the cascade volcanics open circles. A alkali sodium and potassium oxides f iron oxides m magnesium oxide bt tholeiitic basalt fb ferro basalt abt tholeiitic basaltic andesite at tholeiitic andesite d dacite r rhyolite b.
Afm diagram showing the distinction between selected tholeiitic rocks from iceland the mid atlantic ridge the columbia river basalts and hawaii solid circles plus the calc alkaline rocks of the cascade volcanics open circles.
Afm diagram showing the relative proportions of the oxides of alkalis a iron f and magnesium m with arrows showing the compositional change path of the magmas in the tholeiitic and the calc alkaline magma series bt tholeiitic basalt fb ferro basalt abt tholeiitic basaltic andesite at tholeiitic andesite d dacite r rhyolite b basalt ab basaltic andesite a andesite. The three components plotted on afm diagrams are derived from a tetragonal diagram with species al 2 o 3 k 2 o feo and mgo and are ideal for showing mineral assemblage variations as a function of the composition of pelites. Was by eskola 1915 who employed a diagram known as the acf diagram in his study of metamorphic rocks. A alkali sodium and potassium oxides f iron oxides m magnesium oxide bt tholeiitic basalt fb ferro basalt abt tholeiitic basaltic andesite at tholeiitic andesite d dacite r rhyolite b.
