Transcript Science Olympiad

Sedimentary Rocks
February 2012
California Standard
• 3.c.
• Students know how to explain the properties of
rocks based on the physical and chemical
conditions in which they formed, including plate
tectonic processes.
Today’s Objectives
1. List the three main categories of
sedimentary rocks, and describe
how rocks form in each of these
categories.
2. Identify characteristics of
sedimentary rocks using visual
observations.
• Sediments are eroded from other rocks to
make these rocks Interactives . The Rock Cycle . The Rock Cycle
• Compacted – weight of layers of sediment
• Cemented – water carries dissolved minerals
through sediment that acts like cement
• Sediments are compacted and cemented to
make a sedimentary rock
Sediments
Compacted and Cemented
•Three types of sedimentary
rocks:
▫ Clastic
▫ Chemical
▫ Organic
Sediments
Compacted and Cemented
Clastic
Chemical
Organic
• Clastic Sedimentary Rocks –
composed of pieces of other
rocks. Name depends on size of
the pieces.
Clastic
Sandstone
Conglomerate
Shale or Mudstone
Sediments
Compacted and Cemented
Clastic
Conglomerate
Sandstone
Shale
Chemical
Organic
• Chemical Sedimentary Rocks –
composed of minerals once
dissolved in water that
precipitate out of water due to a
change in temperature.
Chemical
Limestone
Evaporites
Sediments
Compacted and Cemented
Clastic
Chemical
Conglomerate
Limestone
Sandstone
Evaporites
Shale
Organic
Organic Sedimentary Rocks –
formed from the remains of
living things
Coal is formed from
Coal
dead plants, usually in
swampy areas, left to
rot and covered with a
lot of sediment for
thousands or millions
of years.
Sediments
Compacted and Cemented
Clastic
Chemical
Organic
Conglomerate
Limestone
Coal
Sandstone
Evaporites
Shale
• Important facts about
sedimentary rocks:
1. Created from sediments weathered and
eroded from other rocks
2. Only rocks that have fossils
3. Only rocks that show water and
sometimes wind patterns (ripples)
4. Only rocks that have layers (sediment
is deposited by water, wind, or ice in
layers)
Fossils
Ripple Marks
Layers
1. Go back and review what you completed on the table for the
Igneous Rocks.
• Are igneous rocks layered?
• Leaved the banded boxes empty for now.
2. Complete your table for the Sedimentary Rocks. You may
take the containers of rocks to your table to share with other
people, but please return the rocks to the correct container,
and return the container to the place where you obtained it.
You have about 20 minutes to look at the Sedimentary Rocks
The Earth started here with Magma