Transcript The Geologic Time Scale/Fossils

Aim: How do Geologist break-up
Geologic Time?
Video 1
Video 2
Do Now:
- Take out your ESRT and turn to page 8-9
- Earth has existed for 4.7 billion years. If this
4.7 billion years were to be scaled down to a
24 hour clock, then how much time on that
clock do you think Humans have existed?
- 12:00:00 AM would be the creation of Earth (4.6BYA)
- 12:00:00 PM would be this very second (Present)
I. Counting Geologic Time
- Eons are the longest periods of time (billions of
years)
- Eras break up Eons (100 million years)
- Periods break up Era’s (10 million years)
- Epochs break up Periods (million years)
In what time Eon, Era, Period and Epoch do we live?
Phanerozoic eon, Cenozoic era, Quaternary period and
the Holocene epoch.
II. Fossils
- the remains or traces of prehistoric life.
- found only in sedimentary rock.
- used to interpret and
describe ancient
environments.
III. Fossil Formation
Two conditions are important for
preservation:
• rapid burial
• hard parts
- teeth
- bone
- shell
Click Here
IV. Reading Fossils
• Index fossils
Tell about one specific time ONLY!. These
fossils must be;
- widespread geographically
(all around the world)
- limited to a short span of time
(only in one layer of rock)
- occur in large numbers
(not just one of them)
In the diagram below, the 4 outcrops examine rock
layers from four places around the world, which fossil
could be an index fossil, WHY?
A
B
C
D
Which fossil can’t be
an index fossil and
WHY?
The first four columns are breaking down time.
This section will also give you the approximate
millions of years ago (MYA) that an event
happened.
This section specifically tells what kind
of living things were on the planet.
Major extinctions are also noted.
These three sections deal
specifically with New York
State.
Ages of rocks in NYS
(If there are no rocks, then there
are no fossils)
Fossils found in NYS
Geologic Events important to
NYS
This section uses the fossils from
above to determine the age of
rocks found in NYS.
i.e. – Fossil A is Cambrian in age
( ~ 488-542 MYA)
This section specifically shows the location of the
continents during five geologic periods.
Please note that they do not correctly line up with the
geologic periods they represent.
North America is colored in solid black.
Use your ESRT to answer the following
questions:
1. If early Pleistocene Mermaids had existed, their
fossil remains would be the same age as which
other types of fossils?
2. When did the Jurassic period end?
3. Which geologic event is associated with the
Greenville Orogeny? (Orogeny = mountains)
4. Could a scientist find shale containing a
eurypterid fossil in NYS?
1. If early Pleistocene
Mermaids had existed,
their fossil remains
would be the same age
as which other types of
fossils?
1st – Locate Pleistocene
2nd – Move to the right until
you cross various fossil
lines
________________________
8 Fossil types can be found
during this Epoch.
Nautiloids, Crinoids,
Mammals, Vascular Plants,
Birds, Corals, Gastropods,
and Brachiopods.
The letters O and S
stand for specific fossils.
(Mastodon, Beluga, or
Condor)
End of the Jurassic Period
Beginning of the Jurassic Period
2. When did the Jurassic
period end?
Answer - 146 Millions of Years
Ago
1st – Locate the Jurassic Period
2nd – Move to the right until
you see the little MYA
numbers
3. Which geologic event is
associated with the
Greenville Orogeny?
(Orogenty = mountains)
1st – Locate Greenville
Orogeny
2nd – Read entire box to
find the geologic event.
Answer -Adirondack Mountain
and Hudson Highlands
formed
1st – Locate eurypterid fossil
2nd – Find M in the CENTER
column
3rd – Is there rock record from
this time period in NYS?
(Look one column to the left)
4. Could a scientist find
shale containing a
eurypterid fossil in
NYS
Answer - Yes
Since the center column
shows fossil and the
column to the left show
the rock record from NYS.
You can hypothesis that if
you found Silurian age
rock it could potentially
have the eurypterid fossil
in it.
In the ESRT,
pages 8 and 9 as well
as page 3 are used to
help read Geologic
time.