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IOWA DEPARTMENT OF TRANSPORTATION
Rocks and Roads
1: Geology of Iowa
- Iowa's Geologic Time Scale
the framework of geological time.
What is a rock? -- Learn that rocks
are not the same.
Iowa's Sedimentary Rocks and Environments
-- Understand where
and how rocks are found in Iowa were formed.
How Geology Affects Iowa's Landscapes
-- Learn about present-
day landscapes and how these relate to geology.
Unit 1 Summary
Unit 1 Glossary -- Definitions provided
for the terms discussed in
Unit 1 Activities -- Activities will
allow students to reinforce the
materials covered in this unit.
There are rocks of many different ages in Iowa. When
earth's history, you learn about the different periods and what
happened during each period. The three general eras in the
Phanerozoic Eon geologic time line are:
Each era has many subdivisions called periods.
To find out more about
these periods, look for more information on the
Bedrock Geology of Iowa (courtesy of the Geological Survey
Bureau, Iowa Department of Natural Resources).
To help you understand the geologic time
scale, let us compare it to a
calendar year from January to December.
1 to November 19 represents the geologic time before the Paleozoic
November 19 to December 13 represents the Paleozoic Era.
December 13 to December 27 represents the Mesozoic Era.
December 27 to December 31 represents the Cenozoic Era.
The portion of the calendar year representing when humans appeared
on the Earth is equal to the last minute of the day.
TO: Unit 1 B. What is a rock?
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