Aim: How do Geologist break-up Geologic Time?

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 12 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.

• Trace fossils are indirect evidence of prehistoric life.

- foot print- burrow

III. Fossil FormationTwo conditions are important

for preservation: • rapid burial • hard parts - teeth - bone

- shell

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IV. Reading Fossils• Index fossils

- widespread geographically- limited to a short span of geologic time - occur in large numbers

• Environments - Fossils can also be used to interpret

and describe ancient environments.

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 Pleistocene2nd – 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)

2. When did the Jurassic period end?

1st – Locate the Jurassic Period

2nd – Move to the right until you see the little MYA

numbers

Beginning of the Jurassic Period

End of the Jurassic Period

Answer - 146 Millions of Years Ago

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

4. Could a scientist find shale containing a eurypterid fossil in

NYS

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)

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.

Answer - Yes

In the ESRT,pages 8 and 9 as well as page 3 are used to help read

Geologic time.