Rocks Flashcards
Rocks that form when magma or lava cools and hardens are called _______________.
Igneous rock
What is melted rock called that is beneath the earth’s surface?
Magma
How does magma reach the earth’s surface?
Cracks and volcanos
What builds up inside the earth and forces magma upward?
Pressure
Materials from earth that people use are known as ________________?
Natural resources
What is magma called when it leaves the volcano?
Lava
Magma slowly ________ and ___________ under the earth’s surface.
- Cools 2. Hardens
What type of rocks would you expect to find around volcanos?
Igneous rock
Granite is an example of what kind of rock?
Igneous rock
What igneous rock has a glassy surface, sharp edges, and was used by the American Indians for arrow heads?
Obsidian
Granite is formed from cooled ________.
Lava
The Hawaiian islands are made of what kind of harden lava?
Basalt
What igneous rock is formed from trapped gasses when a volcano explodes?
Basalt
Scientists use the layers in _____________ rocks to pieces together earth’s history.
Sedimentary
What kinds of rocks for when bits of rocks and minerals are compacted and cemented by earth’s processes?
Sedimentary rock
When the weight of water and air above the sediments press the sediments together this process is called _________________.
Compaction
What is the process called that slowly cements layers of sediments together and form rock?
A cementation
What two factors change rocks into sediments?
Water and wind
What two factors change lower layers of sediment into rock?
Compaction and cementation
Rock salt is an example of what kind of rock?
Sedimentary rock
