Download Act 92-B Geol Time Divisions and AQs

Name
Date
Major Divisions of Geologic Time
Use the chart below to figure out how long each part of your time line should be on your register
tape timeline.
4,500mya/90cm = 50mya. Therefore, one centimeter = 50mya
You will also have several other events to add which your teacher will give to you. Then answer
the Analysis Question below the table once you have completed your timeline.
Column A
Geologic Name
Time span (million years
ago…mya)
Subtract the second number
from the first to get Column B
Early Pre-Cambrian
(Time Card B)
4,500 – 3,800
Late Pre-Cambrian (F)
3,800 – 550
Early Paleozoic (D)
550 – 408
Late Paleozoic (C)
408 – 245
Mesozoic (A)
245 – 65
Cenozoic (E)
Column B
Column C
Length of this time span Length of this time
(millions of years)
span on timeline (cm)
B / 50 = C
700 my
700/50 = 14cm
65 – 0 (present)
AQ2: The total length of your timeline of Earth’s history is 90 cm. Use your timeline to determine
the percentage of Earth’s history that: Formula is… (length of time/50)/90 =
a. single-celled organisms have lived on our planet.
_______ % of Earth's history
b. multicellular organisms have lived on our planet.
©2009 The Regents of the University of California
_______ % of Earth's history