1. SSeeddiimmeennttaarryy RRoocckkss
S6E5. Students will investigate the
scientific view of how the earth’s
surface is formed.
c. Classify rocks by their process
of formation.
Enduring Understanding: Rocks
are grouped based on how they
formed and their mineral
composition.
3. Intro to Sedimentary Rocks
• Produced from weathering products of pre-existing rocks or accumulated biological matter
– Detrital (clastic) rocks produced from rock fragments
– Chemical rocks produced by precipitation of dissolved ions in water
– Organic rocks produced by accumulation of biological debris, such as in swamps or bogs
• Sedimentary rock types and sedimentary structures within the rocks give clues to past environments
• Fossils in sedimentary rocks give clues to the history of life
• Important resources (coal, oil) are found in sedimentary rocks
4. 44.. 33 NNootteess:: SSeeddiimmeennttaarryy RRoocckkss
Sedimentary rocks are layers of sediment
cemented together. The sedimentary process
begins with igneous, sedimentary and metamorphic
rocks weathered which is the breaking down
of rocks followed by erosion the movement
from the Earth's surface by natural processes such
as wind or water flow, through the act of
transportation. The transfer of sediments
(soil particles) from one place to another followed
by deposition the layering after layering of
the sediment. Then Compaction occurs
after the sediments have been deposited.
Cementation the final process acts as glue
or cement to bind the sediments together forming
sedimentary rocks.
http://www.fi.edu/fellows/payton/rocks/create/sedim
ent.htm
5. From Sediment to Sedimentary Rock
• Transportation
– Movement of sediment away from its source, typically by
water, wind, or ice
– Rounding of particles occurs due to abrasion during
transport
– Sorting occurs as sediment is separated according to
grain size by transport agents, especially running water
– Sediment size decreases with increased transport
distance
6. OOrriiggiinn (Formed where)
CCoommpprriissee 7755%% ooff tthhee EEaarrtthh’’ss ssuurrffaaccee
FFoorrmmeedd wwhheenn sseeddiimmeennttss bbeeccoommee
ccoommppaacctteedd aanndd cceemmeenntteedd ttooggeetthheerr
UUssuuaallllyy hhaass llaayyeerrss ccaalllleedd ssttrraattaa
The highest layer has the least
pressure.
The lowest layer has the most
pressure.
7. CCoommppaaccttiioonn
WWhhaatt ddooeess
ccoommppaaccttiioonn mmeeaann??
–LLaayyeerr uuppoonn llaayyeerr ooff
sseeddiimmeenntt bbuuiillddss uupp
aanndd tthhee pprreessssuurree
ffrroomm tthhee uuppppeerr
llaayyeerrss ppuusshheess ddoowwnn
oonn tthhee lloowweerr llaayyeerrss..
–OOnnllyy SSMMAALLLL
sseeddiimmeennttss wwiillll ssttiicckk
ttooggeetthheerr ttoo ffoorrmm rroocckk
The highest layer has the
least pressure.
The lowest layer has the
most pressure.
11. CCllaassttiicc RRoocckk FFaaccttss
Clastic – made of fragments of rock
cemented together with calcite or quartz
Breccia is a term
most often used for clastic
sedimentary rocks that
are composed of large
angular fragments (over
two millimeters in
diameter).
The spaces between the
large angular fragments
can be filled with a matrix
of smaller particles or a
mineral cement that binds
the rock
13. CChheemmiiccaall RRoocckk FFaaccttss
Chemical sedimentary – minerals crystallize
out of solution to become rock
Limestone is a sedimentary
rock composed primarily of
calcium carbonate (CaCO3) in
the form of the mineral
calcite. It most commonly
forms in clear, warm, shallow
marine waters.
It is usually an organic
sedimentary rock that forms
from the accumulation of
shell, coral, algal and fecal
debris.
14. 33.. OOrrggaanniicc SSeeddiimmeennttaarryy RRoocckk
RRoocckkss ffoorrmmeedd ffrroomm oonnccee--lliivviinngg
((oorrggaanniicc)) tthhiinnggss..
EX: Organic
Limestone
Ocean animals called coral create
huge deposits of limestone. As they
die, their skeletons collect on the
ocean floor.
15. OOrrggaanniicc RRoocckk FFaaccttss
Organic sedimentary – remains of plants and
animals
Coal is an organic
sedimentary rock that forms
from the accumulation and
preservation of plant materials,
usually in a swamp
environment.
Coal is a combustible rock and
along with oil and natural gas it
is one of the three most
important fossil fuels.
17. Separating each strata are bedding planes.
Bedding Planes are flat surfaces along which the rock tends to
break.
Caused by changes in grain size.
May also occur after pauses in deposition.
