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Prehistoric Life of North Dakota |
John W. Hoganson |
North Dakota Geological Survey |
CRETACEOUS |
TERTIARY |
QUATERNARY |
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PALEOCENE |
MIOCENE |
Coleharbor Group (glacial drift) |
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Golden Valley
Formation |
Arikaree
Formation |
lake sediment (silt and clay) |
glacial
sediment (till) |
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EOCENE - OLIGOCENE |
river and beach sediment (sand and gravel) |
Flat to rolling land |
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| Niobrara | Lakes and Rivers |
Hilly Land |
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Last modified
December 1, 2006
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