Name______PS/ES Lab Per______

Date______Mr. Landsman

Partner:______

LAB: Geologic Timeline

Background: The geologic time scale is depicted in the center section of your ESRT. It is difficult, however, to express the important events in Earth’s history in a linear fashion on a page of that size. Consequently, the ESRT compress the Precambrian (~4 billion yrs) into an inch strip (bottom) and expand the Phanerozoic (~540 million years) to fill out the page. This provides room to note the important events in geologic time, but may confuse the student trying to understand the concept of linear geologic time. SO…you will create a time line TO SCALE on a paper that lends itself well to depicting L O N G time passage.

Objective: Students will attain a sense of geologic time from a linear representation.

Procedure:

1.  Measure 10 cm from one end of the tape and draw a line across the tape. Write your names in the 10 cm space

2.  Label the line (on your name side) “NOW”. All measurements will be made from this line.

3.  Measuring from the “NOW” line, mark off 1 meter intervals. At each interval, make a line across the tape and label the lines as increasing Billions of years. Ex: 1 billion, 2 billion etc

4.  Measuring from the NOW line, plot the events listed in the table on the next page. Plot lines on the tape. Label each line with the age and event from the table.

BIG QUESTION: How much time is represented by cm, mm, m ????

Conclusions:

1.  Please share your personal experience as you became more enlightened in understanding geologic time. What surprised you? What turned out the way you expected? Does this scale conflict your previous understanding of Earth’s history? Explain. Does the time line (based on scientific evidence and theory) conflict with any personal beliefs regarding Earth’s history? Explain

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2. Which two consecutive events from the table are separated by the longest duration of time? About how many years separate the events? ______

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3. From your ESRT, determine the duration and timeline scale length of the following:

a)  Archean Eon ______

b)  Proterozoic Eon______

c)  Paleozoic Era______

d)  Mesozoic Era______

e)  Cenozoic Era______

4. During what percentage of Earth’s history did Dinosaurs roam the Earth (ESRT).______

LAB: Geologic Timeline

Geologic Eons, Periods, Epochs

Number of years ago /

Event

11 thousand / End of last ice age
1.6 million / Beginning of Pleistocene Epoch
3.5 million / Earliest evidence of humanoids
24 million /
Earliest grasses
65 million / End of Mesozoic / Beginning of Cenozoic / MASSIVE EXTINCTION
142 million / Beginning of Cretaceous
200 million / First mammal fossils
206 million / Beginning of Jurassic
225 million / First birds
251 million / End of Paleozoic / Beginning of Mesozoic / MASSIVE EXTINCTION
290 million / Beginning of Permian
362 million / Beginning of Carboniferous / End of Devonian / MASSIVE EXTINCTION
418 million / Beginning of Devonian / End of Silurian
425 million / Earliest life on land
443 million / Beginning of Silurian / End of Ordovician / MASSIVE EXTINCTION
490 million / Beginning of Ordovician / End of Cambrian
544 million / End of Precambrian
1.2 billion / First animal fossils (marine)
3.5 billion / Oldest rocks (in original form)
4.6 billion / Origin of Earth