Exam 3: Rocks: Materials of the Solid Earth

The quartz in granite begins to melt at 650°C,so if we find a migmatite where quartz has melted in a granitic rock and we know the temperature in the region increased with depth by about 25°C per kilometer,we could estimate the depth that the rock had been at to be about ________.

Intrusive igneous rocks are often characterized as coarse-grained because ________.

Which igneous texture is characterized by two distinctively different crystal sizes?

Metamorphism can affect only sedimentary rocks.

Particle size is the primary basis for distinguishing among various detrital sedimentary rocks.

Obsidian exhibits a(n)________ texture.

Chemical weathering would be most effective ________.

Under the right circumstances,any rock can be transformed into another type of rock in the rock cycle.

Why does magma rise toward the Earth's surface?

The first step in turning a rock into a sediment is ________.

Chalk forms from ________.

Chemically active fluids are ________.

Lava always erupts violently,but magma often flows quietly.

Why do most sediments end up being deposited in oceans instead of other parts of the Earth?

Detrital sediments would predominate in all of the following environments except ________.

Basaltic rocks make up most of the sea floor.

Evaporites have a biochemical origin.

Basalt is the fine-grained equivalent of gabbro.

Limestone is formed primarily through ________.

Which of the following lists the rocks in the order of increasing grain size and increasing grade of metamorphism?