Page 113 - Science Course 3 (Book 2)

Mo11-L2b: How to Determine the Relative Ages of Rocks?

The principle of cross-cutting relationships says that How to Determine the Relative
if one geologic feature cuts across another feature, Mo11–L2b Ages of Rocks?
the feature that it cuts across is older.
KEY CONCEPTS:
1. How can the positions of rock layers be used to
Youngest determine the relative ages of rocks?

Vocabulary A-Z

Let us learn some vocabulary
Oldest

unconformity
Key Concept a surface where rock has eroded away, producing

What is Relative-Age Dating? a break, or gap, in the rock record.
What geologic principles are used in relative-age
dating?

correlation
a method used by geologists to f ll in the missing
gaps in an area’s rock record by matching rocks
and fossils from separate locations.

SUMMARY

What is Relative-Age Dating?

Geologic principles help geologists learn the
relative ages of rock layers.

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