Question

Based on the image below, what would rock classification would be appropriate for an igneous rock containing 19% Olivine, 43% Pyroxene, 36% Calcium-rich Plagioclase, and 2% Hornblende? Composition Rock types FELSIC Granite Rhyolite INTERMEDIATE Diorite Andesite MAFIC Gabbro Basalt ULTRAMAFIC Peridotite Orthoclase feldspar Quartz Plagioclase feldspar Percentage of mineral by volume (Calcium-rich) (Sodium-rich) Pyroxene Muscovite Biotite mica Olivine Amphibole 70% 40% Silica content Sodium and potassium content Iron, magnesium, and calcium content 700'C Temperature at which melting starts 1200C) Felsic Intermediate Mafic Ultramafic

Answer 1

From the given composition we can plot the values of mineral's proportions on the given diagram. This gives us the result that the ne of the rock might be basalt or gabbro depending on the grain size of the rock. Both of these rocks comes under the group of mafic type of igneous rocks.

So,the correct answer in this case will be Mafic.