Transcript Types of Sedimentary Rocks

Types of Sedimentary
Rocks
SWBAT describe the types of clastic
sedimentary rocks; explain how chemical
sedimentary rocks form; describe organic
sedimentary rocks; recognize the importance
of sedimentary rocks
Clastic Sedimentary Rocks
Clastic
Organic
Chemical
Formed from abundant deposits of loose
sediments found on Earth’s surface.
Most common type of sedimentary rock.
Classified by their grain size
Formed from the remains of once-living
things. Limestone is the most common,
and is composed of calcite.
During chemical weathering minerals are
carried into lakes and when water
evaporates the dissolved minerals are left
behind. They can also precipitate from a
super solution.
Grain Size
• What size particles do coarse-grained
clastics have?
– Gravel sized rocks and minerals
• What size particles do medium-grained
clastics have?
– Sand sized rocks and minerals
• What size particles do fine-grained clastics
have?
– Silt sized grains
Clastic Sediments
• Porosity
– The percentage of open spaces between
grains in a rock
• Critical thinking: Why might it be
important to have both fine grained and
medium grained layers in an oil field?
– The larger grain has a higher porosity,
allowing oil to flow freely, while the fine
grained layers would trap the oil
Chemical Sedimentary Rocks
• Evaporites
– The layer of chemical sedimentary rocks left
after settling out of a solution, or from the
solution evaporating
• What are the 3 most common evaportie
minerals?
– Calcite (CaSO4)
– Halite (NaCl)
– Gypsum (CaSO4)
Organic Sedimentary Rocks
• What are organic sedimentary rocks
composed of?
– The remains of once living things; shells, plant
materials
• What is the importance of sedimentary
rocks?
– Give geologists an idea of the surface
conditions in Earth’s past; river flows,
shorelines, animal and plant information