(10 points)
2. The five boxes below represent a geologic cross-cut with five layers (A is on top and E is on
Score
the bottom). The types of rocks are listed on the right side. In each box, write the appropriate
type of rock and explain the answer in relation to the history of the earth's atmosphere.
Answs
A
Limestone layers
|Banded-iron formations
R
Metamorphic rocks with fine grains
Red beds
Chert layersl