How would you classify a coarse grained igneous rock that contains about 50 pyroxene and 50 olivine?

1. A coarse-grained igneous rock that contains about 50 percent pyroxene and 50 percent olivine is an ultramafic rock, or peridotite.

Which describe an igneous rocks in dark silicate minerals with 50% silica?

Rocks which contain large amounts of the ferromagnesian dark matter and about 50% silica are said to have basaltic composition.

What rocks would you find SiO2 mostly in?

Silica is the dioxide form of silicon, SiO2, and occurs mostly as quartz sand, flint, and agate.

Which igneous rock contains the most SiO2?

The most significant variations are the amounts of silica (SiO2) present (see table). Most igneous rocks contain between 45 and 70 wt% silica. They range from lower-silica basalt and gabbro to higher-silica rhyolite and granite.

Which types of igneous rocks are composed of at least 50 percent olivine?

Mafic rocks are low in silica, in the 45-50% range. Ultramafic refers to the extremely mafic rocks composed of mostly olivine and some pyroxene which have even more magnesium and iron and even less silica. These rocks are rare on the surface, but make up peridotite, the rock of the upper mantle.

What igneous rocks are fine-grained?

Origins of Igneous Rocks Similarly, a fine-grained, mafic igneous rock is not only a basalt, it is an extrusive igneous rock that formed from rapid cooling and crystallization of a lava flow at earth’s surface.

How are igneous rocks classified based on SiO2 content?

In a widely accepted silica-content classification scheme, rocks with more than 65 percent silica are called felsic; those with between 55 and 65 percent silica are intermediate; those with between 45 and 55 percent silica are mafic; and those with less than 45 percent are ultramafic.

What magma type contains the greatest amount of SiO2?

What magma type contains the greatest amount of SiO2? Rhyolitic, Andesitic, Basaltic. Rhyolitic contains most SiO2.

Which of the following magma compositions contains the most SiO2?

Answer and Explanation: Rhyolitic magma contains the most silica. Silica is a chemical compound with the formula SiO2.