Exam 11: Igneous Rocks, Intrusive Activity, and the Origin of Igneous Rocks

___ are igneous rocks that are silica-deficient but high in iron and magnesium.

Most of the basalt and gabbro on the ocean floor is created at mid oceanic ridges,which are also ____.

Diorite and andesite are composed of similar amounts of feldspars and ferromagnesian minerals.

A mineral's melting point generally increases with increasing pressure.

How is a sill different from a dike?

Mafic igneous rocks are silica-poor.

_____ rocks have coarse crystals in a fine-grained matrix.

Extrusive igneous rocks are typically fine grained because they crystallized slowly,deep below the Earth's surface.

______ is the predominant igneous rock of the continents.

Rhyolite is considerably more common than granite.

To explain the great volumes of granite plutonic rocks,most geologists think that partial melting of the _______ must take place.

The continuous branch in Bowen's Reaction Series contains the ferromagnesian minerals.

Basaltic magmas crystallize at higher temperatures than granitic magmas.

The melting point of a mineral generally _____ with increasing pressure (or depth).

Granite and ______ are composed predominantly of feldspar and quartz.

______ are extremely coarse-grained with crystal up to 10 meters across.

_____,a coarse-grained rock composed of pyroxene and olivine,is the most abundant ultramafic rock.

________ lava is largely restricted to narrow zones along convergent plate boundaries.

The coarse-grained equivalent of basalt is a(n)______.

Igneous rocks that are silica-rich with high aluminum,sodium,and potassium are _____ rocks.