Rocks
What is the definition of a rock?
Naturally formed solid
What two things make up earth's crust?
Solid and molten rock
What is the rock cycle?
Set of natural processes that form, change, break down and re-form rocks
What happens to the temperature as move deeper into the earth's crust? Why is this temperature important?
*What temperature does it reach?
It gets hotter! It melts solid rock into molten rock.
750-1250 Celsius.
Intrusive - formed by magma that has cooled down under the ground - Ship Rock
Extrusive - formed by lava that has cooled down above the surface - Hawaiian islands
What are rocks normally made of?
They are normally made of multiple minerals.
What do we use rocks for?
Building
artwork
highways
MINERALS!!!
What are igneous rocks?
formed when molten rock cools and becomes solid.
Molten rock about the surface is called___.
Below the surface is called _____.
lava
magma
What factor effects the speed of lava flow?
Silica content. High silica is slow moving and the opposite is also true.
Some rocks are made of one or sometime no _______?
minerals
Give 3 famous examples of places around the world made of rocks.
Pyramids - Limestone
Great wall of China - granite
Mount Rushmore - Carved from Granite
What are sedimentary rocks?
pieces of older rocks, plants and other loose materials get pressed or cemented together. The lower layers of rock are pressed by the higher layers creating pressure and heat.
Igneous rocks that form above the surface are called _____.
Igneous rocks that form below the surface are called _____.
Extrusive.
Intrusive.
What is a landform? Give an example.
natural feature of earth's land surface - mountain, plateau....
Coal and Obsidian are made of no minerals. Why can we call them rocks?
Because they are naturally formed solids.
What do we call the study of rocks?
People who study rocks are called?
What type of maps do they make?
Geology
Geologists
Geological Maps
What are metamorphic rocks?
heat or pressure cause older rocks to change into new types of rocks. the structure of rocks change.
Igneous rocks are classified based on their texture. What does this mean?
Texture describes the size of the crystals.
Pushed to the surface or when the surface is worn by water and wind erosion. Intrusive rocks can be much harder and longer lasting than extrusive rocks.
How are rock and mineral structures different?
Minerals are made of the same proportions of elements. "definite chemical makeup" while rocks have varying amounts of different minerals.
What percentage of earth's crust is made of igneous and metamorphic rock?
95%
*75% of the surface crust is made from sedimentary rock
How to igneous and metamorphic rocks get to the surface of the earth?
They are pushed to the surface by tectonic activity or through erosion of the upper layers.
What does composition mean? What mineral are most igneous rocks generally made of? What two ways can we test for the presence of this mineral in our rock?
-Silicate minerals "silica"
- With our eyes looking at the brightness of the rock and using special equipment to find the exact composition.
Explain the two ways lava gets to the surface. What factor effects the rock formation most. Describe the two different possible rock formations in detail.
Lava can get to the surface via volcanoes or cracks in the earth's surface. When lava moves through cracks it can form plateaus such as the colombia plateau. When lava flows from a volcano the rock formation depends on its flow. High flow speed creates big volcanoes with long sloping sides. Slow speed makes cone shape volcanoes with steep sides.