Visualize five horizontal sedimentary strata exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?
A) Bed 5 is the oldest.
B) Beds l and 3 are older than bed 4.
C) Bed 4 is older than bed 2.
D) Bed 3 is older than beds 2 and 4.

Question

Quizplus · Accepted Answer

Based on the principle of superposition, the lowest layer (bed 1) is the oldest and the uppermost layer (bed 5) is the youngest. Therefore, option A is false. 
As beds 1 and 3 are older than bed 4, option B is true. 
There is no information to determine whether bed 4 is older than bed 2, so option C is false. 
As bed 3 is older than bed 4 (as stated in option B), option D is also true.

Visualize Five Horizontal Sedimentary Strata Exposed in a Cliff or Canyon