Chapter 6 Test Review

Place these notes in your Notebook.

The cooling and hardening of magma deep underground results in a pluton. Plutons are intrusive.

Geode Marble

Shale Gabbro

MetamorphicSedimentary

Sedimentary Igneous

An example of igneous rock is Gabbro.Silty shale is most likely to form farthest from a shoreline.Orthoclase feldspar and quartz is most

likely to be found in felsic rock.All intrusive igneous rocks contain

minerals.Porphyritic texture is not a feature of

sedimentary rocks.Mafic rocks are described by low silica

content, being thin and fluid, and forming dark-colored rock.

Granite and Obsidian are similar in composition only. They do not share the same color, texture or fracture.

An igneous rock characterized by two distinctly different textures is known as porphyry.

Fossils are most likely to be found in sedimentary rock.

Small crystal-lined spheres of silica rock that sometimes occur in limestone are called geodes.

Rhyolite, obsidian, and pumice are all members of the granite family.

Scoria is a mafic rock that is full of holes and made of dense minerals.

Ripple marks are likely to be observed on sandstone rocks.

Rocks are classified by their origin in the rock cycle.

When shale undergoes contact metamorphism it may become hornfels, a dense, hard, fine-grained rock.

Marble is a metamorphic rock that is formed from its parent rock; limestone.

A batholith is a type of pluton.

The formation of clastic rock begins when water moves and relocates rock fragments.

Rocks may form chemically when minerals fall out of solution.

Mafic-Type of magma rich in iron and magnesium and low in silica; forms dark-colored igneous rock containing minerals such as hornblende, augite, and biotite.

Felsic-A type of magma rich in silica that forms light-colored igneous rock containing minerals such as quartz and feldspars.

Essay:

Use the terms volcanic, plutonic, coarse-grained, fine-grained, felsic, and mafic to describe the way in which a granite found in the Adirondack Mountains of New York state is likely to be different from basalt found on the Hawaiian Islands.

The granite in the Adirondack Mountains is a plutonic, felsic, coarse-grained rock. This rock forms the basis of most mountain systems and is lighter in color and less dense than basalt. Basalt found on the Hawaiian Islands is of volcanic origin. This mafic rock is fine-grained, and is darker and more dense than granite.

Use the terms fluids and gases, parent rock, pressure, foliation, and heat to describe the process of regional metamorphism.

During regional metamorphism, rocks are formed when heat and pressure change igneous, sedimentary, or metamorphic parent rock into a new type of rock. The degree of metamorphism is influenced by the amount of heat and pressure the rocks are exposed. The presence of fluids or gases can speed up metamorphic changes. Foliation may occur during regional metamorphism, causing the formation of bands of minerals or parallel layers in the new rock.