8.3 - 8B 3 Classes of Rocks

Which of the following is a direct source of material for the formation of metamorphic rock?

• clasts
• magma
• sediments
• existing rock

Granite forms when liquid magma slowly cools within Earth's crust. If the granite is exposed to intense heat and pressure, it can change to gneiss. Which type of change takes place when granite turns into gneiss?

• Sedimentary rock changes to igneous rock.
• Igneous rock changes to metamorphic rock.
• Metamorphic rock changes to igneous rock.
• Sedimentary rock changes into metamorphic rock.

Igneous rocks form when magma cools and solidifies, As the magma cools, minerals form. What effect will the rate at which the magma cools have on the texture of the igneous rock?

• The faster the magma cools, the smaller the crystals in the rock will be.
• The slower the magma cools, the smaller the crystals in the rock will be.
• The faster the magma cools, the more foliated the rock's texture will be.
• The slower the magma cools, the more foliated the rock's texture will be.

Which of the following correctly describes the difference between a mineral and a rock?

• Rock can be made of inorganic material, but minerals are always organic.
• Rocks are made of naturally occurring material, but minerals can be synthetic.
• Rocks are made of crystalline material, but minerals are always noncrystalline.
• Rock can be made of noncrystalline material, but minerals are always crystals.

A _____ is a naturally occurring, solid combination of one or more minerals or organic matter.

• mineral
• rock
• luster
• Mohs scale

Which of the following best describes how sedimentary rock forms?

• Molten rock beneath the surface of Earth cools and becomes solid.
• Layers of sediment becomes compressed over time to form rocks.
• Chemical processes or changes in pressure or temperature change a rock.
• Molten rock reaches the surface and cools to become solid rock.

Sedimentary rocks can form in several different ways. Which of the following are all different types of sedimentary rock?

• chemical, clastic, organic
• clastic, inorganic, chemical
• organic clastic, nonfoliated
• crystalline, chemical, organic

Rainwater can break down rocks by dissolving minerals in the rocks. Acid rain is rainwater that is more acidic than normal rainwater. Acid rain can also dissolve the minerals in rocks faster than normal rainwater can. Which statement about acid rain is true?

• Acid rain causes less erosion than normal rainwater does.
• Acid rain causes more erosion than normal rainwater does.
• Acid rain causes less weathering than normal rainwater does.
• Acid rain causes more weathering than normal rainwater does.

Slate is a metamorphic rock that forms from shale, which is a sedimentary rock. Which of the following would be needed for slate to form from shale?

• weathering
• heat and pressure
• erosion and deposition
• melting and solidification

Basalt is a dark-colored, fin-grained rock, and granite is a light-colored, coarse-grained rock. Which of the following correctly explains how each forms?

• Basalt forms when lava cools, and granite forms when magma cools.
• Basaalt forms when magma cools, and granite forms when lava cools.
• Basalt forms when lava cools, and granite forms when clasts are cemented.
• Basalt forms when clasts are cemented, and granite forms when magma cools.