Transcript Section Ten Sedimentary Rock Fossils Fossil Fuels

Section Ten
Earth Science
Sedimentary Rock
Fossils
As rocks go through the rock cycle,
weathering and erosion and other
events such as volcanic eruptions
change them.
Sedimentary rocks cover a great deal
of the Earth’s surface and scientists
can discover a lot about the history of
the Earth and events that have
happened by studying them.
Made of sediments.
Sediments are loose
Earth materials (sand,
soil, rock, silt,
pebbles, etc.)
Formed in places
where there once was
water.
They are softer than
other types of rocks.
(they break apart
easier).
Sedimentary
Rock
Usually composed of pieces
cemented or pressed
together. Particles can be all
the same size or a variety of
sizes
Often contain fossils.
Many have layers of
different colors
Fossils
• Most fossils are found in sedimentary rock.
• Fossils are the remains or traces of organisms that lived
long ago.
• The most common way a fossil is created happens when
an organism is quickly trapped in layers of sediment. The
plant or animal slowly decays and the organism is
replaced by minerals that seep through the layers of soil.
• All fossils are old. Scientists study fossils to discover
what life was like on Earth a long time ago.
Sedimentary Rocks and Fossil
Questions
1. A hiker walks from the upper rim to the bottom of a large canyon. At the
bottom of the canyon, the hiker camps for the night. While walking along
the trail, the hiker sees a fossil that looks like a shell. Which statement best
explains the presence of the fossil in the canyon?
A.
B.
C.
D.
Lava formed the fossil.
Wind carved a rock to look like a shell.
The area was covered by a glacier in the past.
The area was covered by liquid water in the past.
2. A leaf is covered in mud during a landslide. After one million years,
this leaf will most likely be…
A.
B.
C.
D.
a fossil
an animal species
a new plant species
a non-renewable resource
3. Coral, clam, and starfish fossils are common in South Dakota. These fossils
are evidence that South Dakota was once…
A.
B.
C.
D.
a forest area
covered by water
flooded by spring rains
at the edge of a tectonic plate
Questions/Explanations
1. animals with shells usually live in the water. If a
fossil of a shell is found in a canyon, the most
logical explanation is that the area had been
covered by water at some time.
2. if an organism is quickly trapped in sediment
before it can decay, over time, due to minerals
seeping into the ground, it can change to a fossil.
3. coral, clams, and starfish are aquatic animals.
If they are found in South Dakota where there is
no oceans, the most logical explanation is that the
area was once covered by water.