Transcript Fossils - RC Schools

Fossils
EQ: How can I determine the
relative age of fossils in sedimentary
rocks?
SPI 0807.5.5
What are fossils?
• Fossil: the trace or remains of an
organism that lived long ago, most
commonly preserved in sedimentary
rock.
What is sedimentary rock?
• Sedimentary rock is formed by sediment
that is deposited over time, which
eventually harden into solid layers of rock.
• Sometimes when organisms die, they are
quickly covered by sediment.
• When the sediment hardens and becomes rock,
the hard parts of the animal are preserved,
creating fossils.
How are fossils formed?
What can be fossilized?
Insects
Animals
Plants
Dinosaurs
Scientists can determine the age of
the fossil by looking at….
1.Absolute Dating:
Atoms
2. Relative Dating:
Layers of rock
Relative Dating:
The bottom layers of
rock are usually the
oldest, and the top
layers are usually the
youngest.
Scientists can use the
order of rock layers
to determine the
relative age of
objects within the
layers.
• Fossils in the
bottom layers
are usually
older than
fossils in the
top layers.
Which layer is the oldest?
Youngest?
Which layer is the oldest?
Youngest?
Which layer formed first? Last?
MOST fossils are found in
sedimentary rock, but there are
some exceptions…
• Some insects have been found perfectly
preserved in amber.
Some animals have been found
perfectly preserved in ice…
La Brea Tar Pit
What is the La Brea Tar Pit?
Draw this picture in your notebook:
On your picture…
1. A fish fossil was found in the oldest
rock layer. Draw the fish fossil in the
oldest layer.
2. An animal skull was found in the
youngest layer. Draw an animal skull
in the youngest layer.
To leave class…
Which fossil layer is the oldest?
a. 1
b. 2
c. 3
d. 4
A scientist would use the relative
dating method to
a.reconstruct past climates.
b.determine the causes of extinction.
c.measure the age of fossils in years.
d.determine whether one rock layer is
older than another rock layer.
Which organisms are likely to be
the same relative age?
a.
b.
c.
d.
A and E
B and D
C and D
A and F
Which fossil is the oldest?
a.
b.
c.
d.
1
2
3
4
Fossils are preserved most often in
which of the following substances?
a.Ice
b.Sedimentary rock
c.Asphalt
d.Amber
Which of the following rock layers in the
diagram have the same relative age?
a. 1 and 6
b. 3 and 7
c. 2 and 9
d. 5 and 10