Rocks Flashcards
What are sedimentary rocks?
Rocks that are formed from sediment that has been compacted and cemented
What is compaction?
Compaction is when the weight of sediment layers force fluids out, decreasing the space between grains.
What is cementation?
Cementation is when dissolved minerals start to crystallize, stitching the grains together.
What is clast?
Clast is small pieces of rock and mineral fragments
What are the 3 types of sedimentary rocks. What is a characteristic for each?
clastic rock- made up of clast
chemical sedimentary rock- has a dominant mineral
biochemical sedimentary rock- contains remains of organisms
How is fossiliferous limestone formed?
It is formed when ocean life collects in water, and when the water evaporates, minerals group together to form a rock with the sea life in it.
What are the two types of igneous rocks, their textures, and how they form?
extrusive- forms quickly when lava hardens and has a smooth, uniform texture (ex. obsidian)
intrusive- forms slowly when magma hardens and has a rough texture due to large crystals (ex. granite)
What type of igneous rock is granite?
intrusive
How does contact metamorphism form metamorphic rocks?
molten rock makes surrounding rocks bend and change their shape
What type of rock is schist?
foliated metamorphic
How are metamorphic rocks formed?
from high pressure and temperature
What is plastic deformation?
a permanent change in the shape of a rock by bending or folding
What are the two types of metamorphic rocks and how are they formed?
foliated- formed from plastic deformation
non-foliated- minerals do not align or interlock
Are there fossils in igneous or metamorphic rocks? Why or why not?
No because they are formed in hot conditions where there is life of organisms, and and fossils would just disintegrate due to the heat
What is the rock cycle?
A cycle showing how a rock is formed and then reformed in many different ways
