Question

UNITS

O
R
G
A
N
1
S
M
3
KEY to rock units
Sandstone
Shale
KEY to fossils
A Starfish
P
Limestone
Dolomite
for coo
Foraminnteran
Coral
Brachiopod
Diplomys
Ammonite 4
Caturus
Spenooters
Lycopod
Crnoid
Reachepod
Tragbite
Tribrachidum
1) Using the letters printed on the left, what is the
order of the rock layers from youngest to oldest?
2) What is the youngest fossil? How do you know?
3) What is the oldest fossil? How do you know?

Answer 1

1. O would be the youngest layer, while M would be the oldest layer.

2. The Foreminniferan would be the youngest fossil since it's closest to the top.

3. The oldest fossil would be the Tribachdium. It's the one closest to the bottom.