Name
Date
Class
Content Vocabulary
LESSON 2
Relative-Age Dating (Pgs. 337-341)
Directions: Write the correct term in the boxes to the right of each definition. Then unscramble the letters from
the numbered boxes to spell a seventh term.
correlation
relative age
inclusion
superposition
index fossil
unconformity
lateral
1. sideways or on the side
2. a fossil of a species that was abundant
and widespread for a brief period of time
3. older or younger, for example
4. the process of matching rock layers
from separate locations
5. describes a gap in the rock record
6. says that the youngest rocks are on
the top
7. When they are unscrambled, the letters from the numbered boxes spell _______________________
which is a piece of an __________________rock that becomes part of a __________________ rock.
Directions: Index fossils are very useful for helping scientists correlate rock layers and determining
the relative age of rocks. Read page 341 then answer the questions which follow.
8. If scientists want to find the relative age of rock layers which are far apart, including on
different continents, what can they conclude if they find an index fossil of the same type in
both of the rock formations? ____________________________________________________
____________________________________________________________________________
9. Index fossils are those that existed for only a __________ period of time. Explain why fossils
which have existed a long time are not helpful in determining the relative age of rock layers.
____________________________________________________________________________
____________________________________________________________________________
Relative-Age Dating (Pgs. 337-341)
Directions: Complete the information about each principle requested.
Original Horizontality
Define: ___________________________________________________
__________________________________________________________
__________________________________________________________
Law of Superposition
Define: ___________________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Inclusion
Define: ___________________________________________________
__________________________________________________________
What kind of rocks are these mostly found in? _____________________
__________________________________________________________
Eroded sedimentary
Unconformity
Define: ___________________________________________________
__________________________________________________________
Which of the 3 types is shown? _________________________Explain:
__________________________________________________________
Cross Cutting Relationships
Define: ___________________________________________________
__________________________________________________________
Which is younger, the rock layers or the intrusion? _________________
Explain:
Name___________________________________________________________________ Date ________________________ Hour ______
Applying Relative Age Principles
(Pgs. 337-341)
Direction: Determine the order of the rock layers and environmental events/changes which occurred
by completing the chart below. List these in the conclusion section as 1st, 2nd, 3rd, 4th, 5th, or 6th.
Clues
Rock Layer A
Rock Layer B
Rock Layer C
Rock Layer D
Rock Layer F
Earthquake
Stream
Claim
Evidence
Reasoning
(Answers the Question)
Order 1st, 2nd, 3rd…
(What Makes You Say So?)
(rules or Laws, vocabulary)
Explain