Name: _____________________ Class Teacher: ________________________ __

Lab Teacher : ___________________________

Geologic History – Reference Tables Pages 8 & 9

The Earth has been around for approximately 4 billion 600 million years, and over this great period of time many, many events have occurred. To keep all of this information in order a time scale was created. This can be found in the Earth Science Reference Tables pg 8-9.

Geologic Time is divided into eons, eras, periods, and epochs.

A. Eons are the largest division of geologic time. Starting on the top left corner of pg 8 you can see the two Eons which geologic time is broken into. These two eons are1. _________________________2. _________________________

Below Eon you will notice the words ‘Million years ago’ – the most recent events are the lowest numbers and the oldest events are the highest numbers.

3. The most recent events are at the _______________(top or bottom) and the oldest events are at the __________________ (top or bottom)

4. Looking at these numbers tell which Eon represents the majority of geologic history.________________________________________________________________

B. Eons are broken into Eras, usually characterized by changing signs of visible lifeList the Eons with their Eras below

_______Era_____0 – 540 (million years ago) eon = ____________________ a) ___________________

b) ___________________c) ___________________

4600 – 540(million years ago) eon = ____________________ Eon Subdivision

a) ___________________b) ___________________

C. Beyond this you’ll see that eras are divided into periods.

1) What are the six periods of the Paleozoic Era.

a) ____________________ b) ____________________ c) _______________________

d) ____________________e) ____________________ f) _______________________

2) What are the two epochs of the Quaternary Period

a) ____________________ b) ____________________

After this you will see the other major areas of the Geologic Time Scale. Important biologic events are below Life on Earth, geology is found below Important Geologic Events in NY. Use this information as well as the other columns to complete the rest of this activity.

1) During which Epoch did the humans first appear? And how many years ago was this?

a) _____________________ b) ______________________(million years ago)

2) During which three Periods did dinosaurs live?

a) ____________________ b) ____________________ c) _______________________

3) Which two important geologic events took place during the Jurassic Period?

a) _____________________________________

b) ______________________________________

4) About how many years ago did the first insects appear?

____________________ (millions of years ago)

5) About how many years ago is the estimated origin of the Earth and Solar System?

____________________ (millions of years ago)

6) How old are the oldest known rocks? From which Eon are they thought to be from?

a) ____________________________(million years old)

b) ____________________________

7) During which period was the Acadian Orogeny?

___________________________

8) How many years ago dinosaurs become extinct?

_____________________________ (million years ago)

9) A complete Rock Record is represented by a bar stretching from the bottom to the top of a period.

Only 5 Periods have a complete Rock Record represented in NY State. These periods listed from

oldest to youngest are

Oldest - _____________________, _______________________, ______________________

_____________________, _______________________ - Youngest

10) For which three periods is there no rock record in NY State.

a)_____________________ b) _______________________ c) ______________________

Critical Thinking Questions

1. During the early Paleozoic era, what was the inferred position of Earth’s landmasses.____________________________________________________________________________________

2. Describe how the position of the Earth’s landmasses changed during the Permian Period to when humans first appear.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Geologic History – Reference Tables, Pages 8 & 9PART II, DAY TWO

11) List the number of years making up the following periods. Also list one important geologic event

that occurred during that time period.

Period Length (mya) Important Geologic Event

Triassic

Quaternary

Cambrian

12) List the Eon, Era, Period, and Epoch for each of the following index fossils. The information can be found by 1 st - locating the picture at the bottom of pg 8 or 9, and 2 nd -Use the letter above the picture along with Time Distribution of Fossils (find the letter then look left to read the Epoch, Period etc.)

13. List the age of the following index fossils in millions of years (mya) and the group of organism that

is belongs to (as listed vertically on the black lines)

14. Which four index fossils were living in the Middle Ordivician?

a) _______________________ b) _______________________

c) _______________________d) _______________________

15. What were the two most recent tectonic events that affected the northeastern United States?

a) _____________________________________________________________

b) _____________________________________________________________

16. What general direction has the North American continent been moving during the last 232 million

years? ________________________________________________________________________

17. List the names of the following index fossils in order from oldest to youngest.

18. How many years ago was the Taconian Orogeny? ______________________ (million years ago)

19. About how many years have humans been on Earth? ______________________ million years

CRITICAL THINKING QUESTIONS

3. One of the most important facts about geologic history is noting when the majority of events took place. Though one eon represents a much larger amount of time that doesn’t necessarily mean that’s when most of the events took place.

During Which Geologic Eon did the majority of events take place? __________________________

________________________________________________________________________________

4. Why are the fossil columns of different lengths? ________________________________________________________________________________________________________________________________________________________________________