ROCKS TEST STUDY GUIDE
Review the techniques used to identify minerals, including Moh’s Scale .
3 types of Rocks:
a)
igneous
B)
sedimentary
c) metamorphic
Define:
Rock: mixture of minerals, organic matter, volcanic glass and other materials
Sediment: broken pieces of rock, dirt, glass, quartz, mineral grains, and plant and animal remains
Weathering: breakdown of rock into sediment due to forces on Earth- wind, water, ice, sand, snow
Erosion: carrying away of sediment due to wind, water, gravity
Deposition: depositing of sediment that has been carried away by erosion
Compaction: over thousands to millions of years, layer upon layer of sediment pushes down, making
the fluids force out, making sediment harder, so it can turn into rock.
Cementation: minerals dissolve in water and recrystallize around the sediment grains making the
sediment and minerals stick together.
What is formed from weathering and erosion of rock? sediment
Which type of rock is made from weathering and erosion? Sedimentary rock
Igneous rocks:
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Rocks formed from magma or lava
Intrusive: formed from magma
Extrusive: formed from lava
Fine-grained ( small or tiny ) crystals means the rock cooled quickly
Large crystals form from rock that has cooled slowly
Note: igneous rocks usually have a combination of minerals in them, making them
multicolored like granite.
Use these rocks , and classify them using your textbook: obsidian, granite, basalt, pumice ( pg 122)
Examples of Intrusive Igneous rocks:
Granite
Examples of Extrusive igneous rocks:
obsidian, basalt, pumice
Sedimentary rocks: rocks made from weathered and eroded rock.
Note: sedimentary rocks usually have only one dominant mineral, like quartz in them.
Formed in 3 different ways: a) organic ( biochemical) b) detrital (clastic )
Define:
c) chemical
use pg. 126-129
Clastic ( detrital ): made up of broken pieces of minerals and rock fragments. The broken pieces and
fragments are the “clasts” . can be pebbles, sand, shells, glass
Chemical: ( formed from evaporates or precipitates ): these rocks form when minerals crystallize
directly from the water. The water evaporates, leaving the minerals, or the minerals crystallize from
the water.
Organic ( biochemical ) : formed by organisms, or contain the remains of organisms. Ex: limestone is
made from shells.
Use these rocks , and classify them using your textbook: ( pg. 127-129)
clastic: conglomerate , shale , sandstone
chemical: limestone, salt , gypsum
organic (biochemical): coal
Metamorphic rocks: changed rock due to changes in:
a)
temperature
b) pressure
or
c) addition of chemical fluids
Met. Rock can be classified as : foliated or nonfoliated
Which one is layered or “banded” in appearance? foliated
What is the rock that is changed called? The parent rock ( pg. 134 )
Use these rocks , and classify them using your textbook: ( pg. 133-136):
Foliated:
Nonfoliated:
slate, gneiss, schist, phyllite
marble, quartzite
THE ROCK CYCLE:
Be able to analyze a rock cycle and answer questions.
Why is the rock cycle not just a simple circle?