Instructions
Read each question carefully. For the objective questions, circle the letter of the best answer. For the subjective and problem-solving questions, write your answers in complete sentences in the space provided (or on a separate sheet of paper).
Part 1: Objective Questions
- Which type of rock is formed from the cooling and hardening of magma or lava?
- A. Sedimentary
- B. Metamorphic
- C. Igneous
- D. Fossilized
- What is the name for molten rock that is found beneath the Earth's surface?
- A. Lava
- B. Magma
- C. Sediment
- D. Crystal
- Sedimentary rocks are formed from...
- A. Heat and pressure
- B. Cooled lava
- C. Layers of sand, silt, and other materials pressed together
- D. The water cycle
- The process of rocks changing due to heat and pressure is called:
- A. Sedimentation
- B. Crystallization
- C. Metamorphism
- D. Erosion
- Which of the following is an example of an igneous rock?
- A. Sandstone
- B. Marble
- C. Limestone
- D. Granite
- Fossils are most commonly found in which type of rock?
- A. Igneous
- B. Sedimentary
- C. Metamorphic
- D. All types equally
- Limestone, a sedimentary rock, can change into which metamorphic rock?
- A. Gneiss
- B. Slate
- C. Marble
- D. Quartzite
- The small pieces of rock, soil, and organic matter that settle at the bottom of lakes and oceans are called:
- A. Magma
- B. Sediments
- C. Crystals
- D. Minerals
- An igneous rock that forms on the Earth's surface from cooled lava is called:
- A. Intrusive
- B. Metamorphic
- C. Extrusive
- D. Sedimentary
- Which rock often has a glassy or very fine-grained texture because it cooled quickly?
- A. Granite
- B. Gneiss
- C. Sandstone
- D. Obsidian
- The process of pressing sediments together is called:
- A. Weathering
- B. Compaction
- C. Melting
- D. Foliation
- Metamorphic rocks that have their grains arranged in parallel layers or bands are said to be:
- A. Non-foliated
- B. Clastic
- C. Foliated
- D. Organic
- Which of these is an example of a sedimentary rock?
- A. Pumice
- B. Slate
- C. Shale
- D. Gneiss
- Granite is an intrusive igneous rock. This means it formed from:
- A. Lava cooling quickly on the surface
- B. Magma cooling slowly beneath the surface
- C. Layers of mud being pressed together
- D. Intense heat and pressure changing another rock
- The process that breaks rocks down into smaller pieces is called:
- A. Cementation
- B. Weathering
- C. Melting
- D. Compaction
- What is the "glue" that holds sediments together in a sedimentary rock called?
- A. Magma
- B. Water
- C. Cement
- D. Pressure
- Which of these is a metamorphic rock?
- A. Basalt
- B. Conglomerate
- C. Slate
- D. Limestone
- The continuous process by which rocks are created, changed, and destroyed is called the:
- A. Water Cycle
- B. Rock Cycle
- C. Carbon Cycle
- D. Life Cycle
- Pumice is a unique igneous rock because it:
- A. Contains fossils
- B. Can float in water
- C. Is made of shells
- D. Has ribbon-like layers
- Sandstone is a clastic sedimentary rock, meaning it is made from:
- A. Once-living things
- B. Cooled lava
- C. The remains of shells
- D. Fragments of other rocks
Part 2: Subjective Questions
- Explain the main difference between magma and lava.
- Describe the two main forces that create metamorphic rocks.
- Why are you unlikely to find a fossil in an igneous or metamorphic rock?
- What are sediments and how are they created?
- Explain the difference between an intrusive igneous rock and an extrusive igneous rock. Give one example of each.
- What do layers (or strata) in a sedimentary rock tell us about its history?
- How can a sedimentary rock like sandstone be formed from a large igneous rock like granite?
- What does the word "metamorphic" mean? How does this relate to how the rocks are formed?
- Name the three main types of rocks and briefly state how each is formed.
- What is the difference between compaction and cementation in the formation of sedimentary rocks?
Part 3: Problem-Solving Questions
- You are hiking and find a rock that has clear, distinct layers of different colored sand and pebbles. It feels gritty and crumbles a little when you rub it. What type of rock have you most likely found? Explain your reasoning.
- A team of geologists finds a mountain range made almost entirely of granite, an intrusive igneous rock. What can they infer about how this mountain range formed, even though it is now high above ground?
- Imagine a piece of shale (a sedimentary rock) gets buried very deep in the Earth's crust during the formation of a mountain range. It is subjected to intense heat and pressure. What type of rock will the shale likely turn into? Will it have layers or bands? What is this feature called?
- You are given two dark-colored igneous rocks. Rock A has large, visible crystals. Rock B has very small, fine crystals that are hard to see. Which rock cooled more slowly? Explain how you know.
- A grain of sand is washed down a river from a mountain and settles on the ocean floor. Describe a possible journey for this grain of sand to become part of a metamorphic rock, mentioning the different rock types it becomes along the way.
Answer Key
Part 1: Objective Questions
- C. Igneous
- B. Magma
- C. Layers of sand, silt, and other materials pressed together
- C. Metamorphism
- D. Granite
- B. Sedimentary
- C. Marble
- B. Sediments
- C. Extrusive
- D. Obsidian
- B. Compaction
- C. Foliated
- C. Shale
- B. Magma cooling slowly beneath the surface
- B. Weathering
- C. Cement
- C. Slate
- B. Rock Cycle
- B. Can float in water
- D. Fragments of other rocks
Part 2: Subjective Questions (Sample Answers)
- Magma is molten rock located beneath the Earth's surface. When magma erupts onto the surface, it is called lava.
- The two main forces that create metamorphic rocks are intense heat (from magma) and intense pressure (from the weight of overlying rocks).
- The intense heat involved in forming igneous (melting) and metamorphic rocks would destroy any plant or animal remains before they could become fossils.
- Sediments are small particles of rock, minerals, or organic matter. They are created by the processes of weathering (breaking down rock) and erosion (moving the pieces).
- Intrusive igneous rocks form from magma that cools slowly deep inside the Earth (e.g., granite). Extrusive igneous rocks form from lava that cools quickly on the Earth's surface (e.g., basalt, obsidian).
- Layers in a sedimentary rock indicate that different types of sediment were deposited at different times. Each layer represents a period of deposition.
- A large granite rock can be broken down into sand-sized grains by weathering. These grains can then be transported by wind or water, deposited, buried, compacted, and cemented together to form sandstone.
- "Metamorphic" means to change form. This relates to how the rocks are formed because they are existing rocks (igneous, sedimentary, or other metamorphic) that have been changed by heat and pressure.
- Igneous: Formed from the cooling of magma or lava. Sedimentary: Formed from the compaction and cementation of sediments. Metamorphic: Formed when existing rocks are changed by heat and pressure.
- Compaction is the process where the weight of overlying sediments squeezes the sediments below together, reducing the space between them. Cementation is when dissolved minerals crystallize in the remaining spaces, "gluing" the sediments together.
Part 3: Problem-Solving Questions (Sample Answers)
- You have likely found a sedimentary rock (like sandstone or conglomerate). The layers show that different materials were deposited over time, and the gritty, crumbly texture is characteristic of sediments being pressed together.
- They can infer that the granite was once a large body of magma (a pluton or batholith) that cooled very slowly deep underground. Over millions of years, tectonic forces uplifted this rock, and the overlying rock and soil eroded away to expose the granite mountain range.
- The shale will likely turn into the metamorphic rock slate. Because of the intense, directed pressure, it will develop layers or bands. This feature is called foliation.
- Rock A cooled more slowly. The slow cooling allowed more time for large crystals to grow. Rock B cooled quickly, so the crystals had very little time to form and are therefore very small.
- The grain of sand is deposited on the ocean floor and buried. Over time, it is compacted and cemented with other sand grains to become part of a sedimentary rock (sandstone). If this sandstone is then buried deeper and subjected to intense heat and pressure (perhaps during mountain building), it will transform into a metamorphic rock (quartzite).