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This presentation overviews the different eras of rocks and fossils to determine their orientations and estimation of their age. A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, etc.
1.
Rock and Fossil Record
Chapter 10
8th grade
2.
The Present is a
key to the past.
3.
Change in earth has
occurred slowly over
time and continues to
change the same way now
4.
All geologic change
occurs suddenly
5.
Relative Dating
Determines whether an
object or event is older
or younger than other
objects or events
6.
States that younger
rock lies over older rock
7.
Geologic column
Ideal sequence of rock
layers in rock formation
arranged from the oldest
to the youngest
9.
In your notes!!!
Draw figure 4 and 5 on
page 245
Fault, intrusion,folding
tilting
Use different colors to
show layers
10.
Disturbed rock layers
Fault
Intrusion- Magma
Folding
Tilting
15.
In your notes:
Draw figure 7,8,9 on
page 247 and label
disconformity
unconformity
angular unconformity
16.
Missing rock layers
create gaps in rock layer
sequence
17.
Types of unconformities
Disconformity- entire
layer is missing
Nonconformity-
sedimentary rock on top of
igneous rock with erosion
18.
Angular unconformity
Between horizontal rock
layers and tilted rock
layers
21.
Non-conformity
Sedimentary
23.
Science Log Feb 7, 2008
What are 4 types of ways
rocks can be disturbed?
What are 3
Finish coloring your rock
layers assigned yesterday
24.
Absolute Dating
Finding the age of an
object, such as a fossil
or rock layer by
determing the number of
years it has existed.
25.
Atoms have the same
number of protons, but
different number of
neutrons.
26.
Radioactive isotopes
Unstable
Break down easily
Break down is called
radioactive decay
27.
Radiometric dating
Compares the amount of
parent material to
daughter material.
28.
Half life
The amount of time it
takes for ½ of the
radioactive sample to decay
The more new daughter
material, the older the
rock is
29.
Uranium-Lead Method
Used on rocks more than
10 million years old
30.
Potassium-Argon Method
Used on rocks older than
100,000 years
31.
Carbon 14 method
Used for dating that
lived within the last
50,000 years.
32.
Science log-Feb 8, 2008
What is the difference between
relative dating and absolute
dating?
How old is the material on the
board if the half-life is 5,000
years?, what if the half-life is
5,730 years?, what if the half-
life is 20,000 years?
33.
Any naturally preserved
evidence of life
34.
Process when minerals
fill in pore spaces of an
organisms tissue
35.
Organisms tissue is
completely replaced by
minerals
36.
Types of fossils
fossils in amber
mummification
frozen fossils
fossils in tar
37.
Trace fossils
Any naturally preserved
evidence of an animals
activity
Footprints,burrows and
coprolites
38.
Index fossils
Fossils of organisms that
only lived a short time
span
Ex. trilobites
39.
Science Log Feb 11, 2008
What is the difference
between a trace fossil
and an index fossil?
40.
Geologic Time Scale
Divides Earth’s 4.6
billion YEARS of history
Changes in biodiversity
41.
Eons
Eras
Periods
Epochs
42.
Paleozoic Era
“old life”
Beginning, no land animals
Middle, plant developed
End, amphibians and insects
Then, 90% of all organisms
became extinct
43.
Mesozoic Era
Middle life
Age of reptiles
At the end, 50 of all
animals and all dinosaurs
became extinct
44.
Cenozoic Era
Recent Life
Age of mammals
Mammals become
abundant
45.
Homework-Due Friday
Voc. Worksheet
page 266 #6-13 and
22-25
Picked up in homeroom
Friday-counts as a test
grade
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