Chapter 8 Section 1
Page 190 #’s 1-6
Determining Relative Age
1. Explain why it is important for
scientists to be able to
determine the relative age of
rocks.
• So they can understand the age and
history of Earth
2. State the principle of
uniformitarianism in your own
words.
•
It’s like what happened in the past is just
like what is happening now man.
3. Explain how the law of
superposition can be used to
determine the relative age of
sedimentary rock.
•
According to the law, a rock layer is
always younger than the rock layer
below it if the layers are undisturbed.
4. Explain the difference
between an unconformity and a
nonconformity. .
•
An unconformity is a break in the rock
record; a nonconformity is a kind of
unconformity in which metamorphic or
igneous rock layers are overlain by
sedimentary rock layers.
5. Compare an angular
unconformity with a
disconformity.
•
In an angular unconformity, tilted rock
layers are overlain by horizontal rock
layer. In a disconformity, the rock layers
above and below the unconformity are
parallel.
6. Describe how the law of
crosscutting relationships helps
scientists determine the relative
age of rocks.
•
The law of crosscutting relationships
helps scientists understand that a body
of rock or fault is always younger than
any other body of rock that it cuts
through.
The End !!!