What have we already learned about sediments/sedimentary rocks?
Sediments may include: Fragments of other rocks that have been worn
down into small pieces Organic materials: the remains of
once-living organisms Chemical precipitates: minerals that get left
behind after the water evaporates form a solution Sedimentary rocks
are part of the rock cycle! They are made from sediments.
Sedimentary rocks are formed by the compaction of sediments.
Slide 3
How do we get sediments? Most sediments settle out of water
Example: running waters in rivers One layer of sediment is
deposited at a time. When sediments harden, the layers are
preserved. In large outcrops of sediments, you can see the layers
that make up sedimentary rocks.
Slide 4
Environments where sedimentary rocks form: There are MANY
environments where sedimentary rocks can form. Mostly places that
have water involved!!! Beach, oceans, lakes, ponds, rivers, marshes
swamps Also find sedimentary rocks forming in deserts and mountains
where avalanches have occurred.
Slide 5
How do sedimentary rocks form?? 1. Sediments accumulate 2.
Lithification occurs
Slide 6
Lithification Lithification: the hardening of layers of loose
sediment into rock Made up of 2 processes 1. Cementation: occurs
when substances crystallize or fill in the spaces between the loose
particles of sediment 2. Compaction: when sediments are squeezed
together by the weight of layers on top of them
Slide 7
Classification of Sedimentary Rocks Clastic Rocks: sedimentary
rocks made of cemented, non- organic sediments Bioclastic Rocks:
sedimentary rocks made of cemented organic sediments Chemical
Sedimentary Rocks: sedimentary rocks made by the hardening of
chemical precipitates
Slide 8
Summary Write a 3 sentence summary about sedimentary
rocks!!
Slide 9
How do we get metamorphic rocks? Metamorphic rocks start off as
igneous, sedimentary, or other metamorphic rocks. These rocks are
changed when heat or pressure changes the rocks physical/chemical
make-up. Metamorphism DOES NOT completely melt the rock, it just
heats it up and changes it!
Slide 10
Foliation Foliation: flat layers in rocks that form as the
rocks are squeezed by pressure. Normally forms when pressure was
exerted on a rock from one direction. If pressure is exerted from
all directions, no foliation occurs.
Slide 11
Types of Metamorphism 1. Contact metamorphism: occurs when
magma contacts a rock, changing it by extreme heat 2. Regional
metamorphism: occurs when great masses of rocks change over a wide
area due to pressure deep within the earth or through extreme
pressure from rock layers on top of it.
Slide 12
Summary Write a 3 sentence summary about metamorphic
rocks!!
Slide 13
Vocabulary for Ch. 4 1. Sediments 2. Solidify 3. Intrusive 4.
Extrusive 5. Mafic 6. Felsic 7. Ultramafic 8. Compaction 9.
Cementation 10. Clastic Rock 11. Bioclastic Rock 12. Chemical
Sedimentary Rock 13. Contact metamorphism 14. Regional metamophism
15. Foliation