The Geosphere Flashcards
True or False: Lava is the liquid form of rock.
True
Where do Igneous rocks get their name?
Igneus = fiery, burning hot
What type of rock makes up 90% of the earth’s crust?
Igneous rocks
What type of rock is Granite?
Igneous
True or False: Obsidian is Igneous
True
What is magma?
Molten rock BELOW the earth’s surface
True or False: Magma cools quickly
FALSE
Why is magma able to turn into granite underground?
Because it cools slowly, because it is insulated by the surrounding rock. This gives time for the natural elements to form the large crystals that make up granite.
What is lava?
Molten rock that flows ABOVE the ground.
True or False: Lava cools quickly
True
Why does lava cool quickly?
Partially due to the thickness (or thinness) of the lava once it leaves the ground, and also due to heat loss due to the air and the earth below it.
True or False: Obsidian is made up of tiny crystals.
True
Why are the crystals different between obsidian and granite?
Because of the rapidity of the cooling process. Lava cools much quicker to make obsidian, so the crystals don’t have as much time to form.
What is the weathering process?
When water, wind, snow, and other natural elements and forces chip away at the rock slowly over time.
What are the tiny pieces of rock that get chipped away due to weathering?
Sediments
What is erosion?
When the sediments from rocks get moved around by wind and water.
True or False: New rocks can be formed from sediments
True
What are sedimentary rocks?
Rocks that are made up of the sediment of other rocks.
What is lithification?
Lith = stone
“stoneification”
Becoming a rock, the process of sediments turning into a rock
How many (general) steps are in the lithification process?
- Deposition
- Compaction
- Cementation
What is Deposition?
When sediment is deposited in a new location and is spread out to form a layer.
What is compaction?
When multiple layers of sediment (caused by deposition) get squished together due to gravity. They slowly compact on each other.
What is cementation?
When water moves between the layers of compacted sediment, it leaves behind dissolved minerals. These minerals “stick” the layers of sediment together.