TYPE OF ROCKS
This type of rock forms when melted rock (magma or lava) cools and hardens.
Igneous Rocks
The rock cycle describes how rocks change from one type to another over what period of time?
A very long time (millions of years)
What is the name for a scientist who studies rocks?
Geologist
What is the first step to becoming a fossil?
Die
What property describes how hard it is to scratch a mineral?
This type of rock forms when lava cools quickly on Earth’s surface.
Extrusive Igneous Rocks
What process breaks rocks into smaller pieces to form sediment?
Weathering
What tool might geologists use to study the layers inside rocks?
Microscope or Magnifying Glass
Fossils are most commonly found in which type of rock?
Sedimentary Rocks
This natural material made from rock is commonly used in kitchen countertops and floors.
Granite
Why are fossils rarely found in metamorphic rocks?
Heat and pressure during metamorphism can destroy fossils.
What two main conditions change rocks into metamorphic rocks?
Heat and Pressure
Why do geologists study rock layers to learn about Earth’s past?
Because rock layers show information about past environments, fossils, and geological events.
A dinosaur footprint preserved in rock is an example of what type of fossil?
Trace Fossil
A scientist finds a rock with crystals that are very large. What does this suggest about how the rock formed?
The magma cooled slowly underground, allowing large crystals to form.
A rock contains fossils and visible sedimentary layers. Explain why scientists classify it as a sedimentary rock.
Because sedimentary rocks form from layers of sediment that are pressed together over time, and fossils are usually preserved in these layers.
Sediments become sedimentary rock through two processes. Name both processes.
Compaction and Cementation
Anton finds a seashell fossil near a mountain. What can they conclude about the area’s past?
The area was once under the sea or ocean before the land was lifted up to form a mountain.
Why are fossils rarely found in igneous rocks?
Because the heat from molten rock would destroy the remains of organisms.
This rock is often used in statues and famous buildings because it can be polished and carved easily.
Marble
Why do sedimentary rocks often show clear layers while igneous rocks usually do not?
Sedimentary rocks form from layers of sediments deposited over time, while igneous rocks form from cooled magma or lava.
Explain how an igneous rock could eventually become a sedimentary rock in the rock cycle.
The igneous rock is weathered and eroded into sediments. These sediments are deposited, compacted, and cemented together to form sedimentary rock.
Rock scientists use the Law of Superposition. What is the Law of Superposition?
This law states that lower rock layers are usually older than the layers above them.
A fossil of a land animal is found in one rock layer, and above it is a rock layer with marine fossils. What might this tell scientists about environmental changes?
The area may have changed from land to ocean over time.
Some houses use stones on the outside walls. Explain one advantage of using rocks as a building material.
Rocks are strong, long-lasting, and resistant to weather, so they help buildings last longer.