Types of Rocks
What is a rock?
A natural solid material made of one or more minerals.
How do igneous rocks form?
Hot, molten lava or magma cools and hardens.
What are organic rocks made of?
The remains of living things
Which type of rock does marble form?
Slate
A series of natural changes that cause one type of rock to become another type of rock.
Rock cycle
What are the three main types of rocks?
1. Igneous
2. Sedimentary
3. Metamorphic
What is the difference between intrusive and extrusive igneous rocks?
- Intrusive rocks form underground and have coarse texture with large crystals.
- Extrusive rocks form on the earth's surface and have a smooth texture with little or no crystals.
What percent of rocks on the earth's surface are sedimentary?
57%
Which rock type does slate form?
Shale
Name one of the underground forces that can change rocks.
1. Heat
2. Pressure
How are rocks classified?
How they are formed.
What is the difference between magma and lava?
- Magma is hot, liquid rock inside the earth
- Lava is magma that reaches the surface of the earth
What is a conglomerate rock?
What is a foliated rock?
Metamorphic rock in which minerals have been rearranged into visible bands.
How does rock become magma?
It must become hot enough to melt inside the earth
Which type of rock is most common?
Sedimentary
Is obsidian an intrusive or extrusive rock? How can you tell?
Extrusive. It has little or no crystals.
What are the three main types of sedimentary rocks?
1. Clastic
2. Chemical
3. Organic
What is a nonfoliated rock?
Metamorphic rock that does not show bands
How might sedimentary rock become metamorphic rock?
If buried deep enough, sedimentary rock may be altered by intense heat and pressure.
What information about the earth can rocks provide?
- Rocks can tell us about earth's history
- Help locate resources such as oil and coal
- Explain changes in the environment
Is granite an intrusive or extrusive rock? How can you tell?
Intrusive. It has large crystals.
How do sedimentary rocks form?
Bits of rocks, minerals, and organic matter settle out of moving water, wind, or ice. These sediments then become compacted and cemented to form sedimentary rocks.
How do metamorphic rocks form?
Rocks are transformed by heat, pressure, and hot fluids into metamorphic rocks.
How might metamorphic rock become igneous rock?
Metamorphic rock could become hot enough to melt, becoming magma. When it cools, it would then be igneous rock.