The Rock Cycle Flashcards
(22 cards)
What is a rock?
A consolidated mass of minerals (multiple minerals or a single mineral mass)
Is a pile of sand a rock?
No, because it is not consolidated
What are the three classifications of rock?
Igneous, Sedimentary and Metamorphic
What is Igneous rock?
Rock formed from magma/lava. Types are differentiated by where the rock was formed.
What are the two criteria for categorizing Igneous rock?
Texture and Composition
How is Texture categorized for Igneous rock?
Intrusive vs. Extrusive
Intrusive= Course texture (formed inside the earth, slower cooling results in larger crystals)
Extrusive= Fine texture (lava formed outside of earth, faster cooling results in smaller crystals)
How is Composition categorized for Igneous rock?
Mafic vs. Felsic
Mafic= denser, usually darker in color, thinner (less viscos), oceanic crust
Felsic= less dense, lighter in color, thicker (more viscos), continental crust
What are the final 4 categories of Igneous rock?
- Extrusive Felsic
- Extrusive Mafic
- Intrusive Felsic
- Intrusive Mafic
What are the 2 Igneous rock types?
Sills= horizontal Dikes= verticle
What is Sedimentary rock?
Rock formed from bits of existing rock stuck together
What is Lithification?
A process during which sediments are compacted, cemented and hardened into rock (ie sands becoming sandstone)
What are clastic sediments?
Clastic: Broken up bits of existing rock material
Clastic sediments are rocks made from lithified bits of other rock
What are chemical sediments?
Anything not clastic
What are the 2 types of chemical sediments?
Organic and Evaporates
What are organic sediments?
Rock formed from bones, shells, etc. beneath the ocean
What are evaporates?
Salt left behind by evaporated water
What is Metamorphic rock?
Rock formed when existing rock is subjected to processes that cause transformation (the “butterfly” of rocks) ie- a whole rock made from a whole rock
How do Sedimentary and Metamorphic rocks differ?
Sedimentary rocks are made of broken up bits of existing rocks. Metamorphic rocks are made from existing whole rocks that have undergone a transformative process
When does Metamorphic rock occur?
It occur when high heat and pressure come together
- Compression during crustal collisions (Tetonic plates colliding)
- Stressed along earthquake fault lines
- Compressed under the weight of overlaying rock
- Comes in contact with rising magma
How is Metamorphic rock described?
As Foliated or Unfoliated
What does Foliated mean?
Striped
What does Unfoliated mean?
No stripes
