Geology in the Dubuque Area

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Stop 1:  Little Maquoketa River Mounds State Preserve – Mississippi River History and Drainage Diversion. 

 

 

by E. Arthur Bettis III

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Ordovician Galena Group Strata In The Dubuque Area; Stop 2:  Tollbridge Inn, Eagle Point Quarry. 

 

 

by Brian J. Witzke, Richard C. Heathcote, and Raymond R. Anderson

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Stop 3:  Eagle Point Park – Landscape Overview. 

 

 

by E. Arthur Bettis III

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Upper Ordovician Brainard Shale (Maquoketa Formation);  Stop 4: Highway 20, Dubuque County. 

 

 

by Brian J. Witzke, Raymond R. Anderson, Richard C. Heathcote

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Lower Maquoketa Phosphatic and Organic-Rich Facies, Upper Ordovician, Dubuque County; Stop 5:  Graf. 

 

 

by Brian J. Witzke and Richard C. Heathcote

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