of Contents

Lesson 1
Planet Earth
Lesson 2
The Ground We Stand Upon
Lesson 3
The Earth’s Surface
Lesson 4
Erosion / Deposition
Lesson 5
Sediments / Fossilization
Lesson 6
Volcanism / Deformation of rocks / Continents
Lesson 7
Metamorphism / Radioisotope Decay
Lesson 8
Ways to date the Earth
Lesson 9
Great geologic events of the past
Lesson 10
Questions people ask

The Geology Book

The Geology Book
by Dr John D Morris

Lesson 8

Ways to date the Earth


The Geology Book


pp. 54-57


Psalm 18

Vocabulary Words:

  • Magnetic field
  • sediment


  1. What does measuring the chemicals in the ocean tell us about the age of the earth?
  2. What does measuring the total volume of the continents and the rate of sediment erosion tell us about the age of the earth?
  3. What does the amount of helium in the atmosphere tell us about the age of the earth?
  4. What does the rate of decline in the earth’s magnetic field tell us about the age of the earth?
  5. What conclusion can be drawn about the age of the earth from the various dating methods discussed in this chapter?


This is a simple experiment to study wind erosion. Stick a piece of two-sided tape on one side of several different wooden stirring paddles (you can get these from a paint store) and place them in the ground in various places around your home. Make sure they don’t all face in one direction. Have one face North, another South, etc. At regular intervals, check the amount of dust or soil sticking to the tape. Depending on the amount of wind and the direction from which it blows, you will see that some paddles collect more dust than other paddles. More soil will stick to the paddles where wind erosion is taking place. What is in the way, preventing dirt from sticking to those paddles where little is collected?

Biblical Geology Properly Understanding the Rocks (DVD)

Additional resources:


  1. Technically, measuring the chemicals doesn’t tell us anything about the age of the earth—it just tells us how much of each chemical is present in today’s oceans. However, we can attempt to figure out how old the oceans are by assuming various things. Some studies indicate that the oceans can’t be older than 62 millions years.
  2. Again, the actual measuring doesn’t tell us anything about the age of the earth. It’s only when we begin assuming things about the past that we try to figure out how old the continents are based on present-day measurements—that they can’t be older than 15 million years.
  3. See above answers—that the atmosphere can’t be older than 2 million years.
  4. Measuring the rate of decline in the magnetic field simply tells us how much it has declined within the measured time period. However, we can extrapolate back and time and suggest that 10,000 years ago the magnetic field would have been too strong for life to exist.
  5. A majority of methods used to age-date the earth yield ages far less than the acclaimed billions of years.