Introduction

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IOWA’S PLACE IN THE DEVONIAN WORLD

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AN INTRODUCTION TO DEVONIAN FOSSILS OF THE CORALVILLE LAKE AREA

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Sponges and Stromatoporoids

3

 

The Corals

4

 

The Bryozoans

5

 

The Brachiopods

5

 

The Molluscs

6

 

The Echinoderms

7

 

Trilobites and Other Arthropods

8

 

Miscellaneous Fossils

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Microfossils

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The Fish

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STRATIGRAPHY AND DEPOSITION OF DEVONIAN BEDROCK UNITS IN THE CORALVILLE LAKE AREA

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MIDDLE DEVONIAN WAPSIPINICON GROUP

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Pinicion Ridge Formation

12

 

 

Davenport Member

12

 

 

 

 

CEDAR VALLEY GROUP

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Little Cedar Formation

13

 

 

Solon Member

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Rapid Member

18

 

Deposition of the Little Cedar Formation

23

 

Coralville Formation

25

 

 

Cou Falls Member

25

 

 

Iowa City Member

26

 

Deposition of the Coralville Formation

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Lithograph City Formation

27

 

 

State Quarry Member

28

 

 

Andalusia Member

28

 

Deposition of the Lithograph City Formation

29

 

 

 

 

UPPER DEVONIAN LIME CREEK FORMATION

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“North Liberty Beds”

30

 

 

 

 

STOP 1.  CORALVILLE DAM EMERGENCY SPILLWAY, OVERFLOW CHANNEL: DEVONIAN FOSSIL GORGE

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STOP 2A.  MEHAFFEY BRIDGE ROADCUT; MERRILL A. STAINBROOK GEOLOGICAL PRESERVE

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STOP 2B.  MEHAFFEY BRIDGE SOUTH, CORALVILLE LAKE SHORE – DEVONIAN AND PENNSYLVANAN CHANNEL-FILL DEPOSITS

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STOP 3.  THE OLD STATE QUARRY – TYPE SECTION OF THE STATE QUARRY MEMBER

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STOP 4.  SUGAR BOTTOM AREA – STATE QUARRY MUDSTONES OVER RAPID MEMBER

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