Rocks Lecture Flashcards
What is a rock?
A natural solid mixture of minerals, smaller rock fragments, organic matter, or glass.
What are the three types of rocks?
Igneous, sedimentary, and metamorphic.
What are the different types of igneous, sedimentary, and metamorphic rocks?
Igneous: intrusive, extrusive
Sedimentary: clastic, chemical, organic
Metamorphic: foliated, non-foliated
How are intrusive and extrusive rocks formed?
Intrusive rocks are formed when magma cools underground. Cool slower.
Extrusive rocks are formed when magma cools above ground. Cool faster.
What is a sediment?
Small fragments of rocks and minerals.
What is lithification?
The process by which sediment turns to rock.
What is compaction?
When the weight from layers of sediments forces out fluids and decreases the space between grains.
What is cementation?
The process by which minerals dissolved in surrounding water crystallize between grains of sediment.
What are clastic sedimentary rocks?
Sedimentary rocks that are made up of broken pieces of minerals and rock fragments.
What are chemical sedimentary rocks?
Rocks that form when crystals precipitate out from a liquid. Composed of one dominant mineral and are uniform in color.
What are organic sedimentary rocks?
Plant bodies are lithified to become coal.
When/how and where do metamorphic rocks form?
When rocks are exposed to extreme temperature or pressure or chemical rich fluids.
Along plate boundaries.
What is foliation?
If pressure is exerted on one side of the metamorphic rock, it forms layers.
