Science Rocks Flashcards
How are igneous rocks formed?
They are formed from liquid molten material (magma), that hardens to form rocks. It comes from volcanoes.
What are the 3 types of main rocks?
Sedimentary, igneous and metamorphic
Explain the two sub-groups for igneous rocks?
Extrusive- igneous rocks that form on the surface of the earth
Intrusive- igneous rock that forms in the earth/mantle
How can you tell what an extrusive rock is? Intrusive?
Intrusive rocks are coarse grained
Extrusive rocks are glassy or holey (fine grained)
What is the term for magma cooling in 2 stages, slowly then quickly?
Porphyritic
How does a metamorphic rock form?
It forms when a parent rock changes from heat, pressure, and/or chemical reactions
What are the two subgroups for metamorphic rocks? Explain them
Foliated- when the mineral grains are flattened and lined up in straight lines
nonfoliated- when mineral grains are randomly placed throughout the rock
What are igneous rocks that are dark colored and more dense from a lot of iron and magnesium?
Basaltic
What are rocks said to be like when they have a lot of silica and are less dense and colored
Granatic
What is in between Granatic and basaltic
Andesitic
How are sedimentary rocks form?
Sediments
How are clastic sedimentary rocks formed?
Made up of broken fragments of other rocks.
How are chemical sedimentary rocks formed?
Formed from minerals that are dissolved in water
How are organic sedimentary rocks formed?
It is formed from remains of once living organisms
