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 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) Video 1 Video 2

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 rapid burial hard parts - teeth - bone - shell Click Here Two conditions are important for preservation: rapid burial hard parts - teeth - bone - shell

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? C A B 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.

Major extinctions are also noted. This section specifically tells what kind of living things were on the planet. Major extinctions are also noted.

Geologic Events important to NYS 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

i.e. – Fossil A is Cambrian in age 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)

North America is colored in solid black. 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: If early Pleistocene Mermaids had existed, their fossil remains would be the same age as which other types of fossils? When did the Jurassic period end? Which geologic event is associated with the Greenville Orogeny? (Orogeny = mountains) Could a scientist find shale containing a eurypterid fossil in NYS?

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) If early Pleistocene Mermaids had existed, their fossil remains would be the same age as which other types of fossils?

Answer - 146 Millions of Years Ago End of the Jurassic Period Beginning of the Jurassic Period When did the Jurassic period end? 1st – Locate the Jurassic Period 2nd – Move to the right until you see the little MYA numbers Answer - 146 Millions of Years Ago

Answer -Adirondack Mountain and Hudson Highlands formed 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) 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. Could a scientist find shale containing a eurypterid fossil in NYS Answer - Yes

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