Coalmont Formation

Coalmont Formation
Stratigraphic range: Paleocene-Wasatchian ~60–50  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Coalmont Formation, Jackson County, Colorado
Type	Formation
Underlies	North Park Formation
Overlies	Cretaceous strata [1]
Thickness	9,000 feet (2,700 m) [1]
Lithology
Primary	Sandstone
Other	Clay, Shale, Coal
Location
Coordinates	40°24′N106°30′W / 40.4°N 106.5°W / 40.4; -106.5
Approximate paleocoordinates	45°00′N90°18′W / 45.0°N 90.3°W / 45.0; -90.3
Region	Colorado
Country	United States
Extent	North Park intermountain basin
Type section
Named for	Coalmont, Jackson County, Colorado [2]
Named by	A. L. Beekly [2]
Coalmont Formation (the United States) Show map of the United States Coalmont Formation (Colorado) Show map of Colorado

The Coalmont Formation (Tmc) is a geologic formation that outcrops in the North Park intermountain basin in Colorado. It contains fossil plants and coal layers dating back to the Paleogene period. ^[3]

Fossil content

Geologic map of the North Park Basin with the Coalmont Formation indicated in light green (Tmc)

The following fossils have been reported from the formation: ^[3]

Insects

• Calandrites hindsi ^[4]
• ?Calandrites ursorum ^[5]
• ?Carabites arapahoensis ^[5]
• Curculio beeklyi ^[5]
• Ophryastites hendersoni ^{[4] [5]}

Flora

• Allantodiopsis erosa ^[6]
• Ampelopsis acerifolia ^[6]
• Betula stevensoni ^[6]
• Carya antiquorum ^[6]
• Cercidiphyllum arcticum ^[6]
• Cissus marginata ^[6]
• Eucommia serrata ^[6]
• Fraxinus eocenica ^[6]
• Glyptostrobus nordenskioldi ^[6]
• Hydromystria expansa ^[6]
• Lastrea goldiana ^[6]
• Laurophyllum perseanum ^[6]
• Laurus socialis ^[6]
• Lygodium coloradense ^[6]
• Metasequoia occidentalis ^[6]
• Mimosites coloradensis ^[6]
• Nordenskioldia borealis ^[6]
• Persea brossiana ^[6]
• Platanus nobilis ^[6]
• P. raynoldsi ^[6]
• Prunus corrugis ^[6]
• Pterocarya hispida ^[6]
• Quercus greenlandica ^[6]
• Q. sullyi ^[6]
• ?Robinia wardi ^[6]
• Sassafras thermale ^[6]
• Sparganium antiquum ^[6]

Wasatchian correlations

Wasatchian correlations in North America

Formation	Wasatch	DeBeque	Claron	Indian Meadows	Pass Peak	Tatman	Willwood	Golden Valley	Coldwater	Allenby	Kamloops	Ootsa Lake	Margaret	Nanjemoy	Hatchetigbee	Tetas de Cabra	Hannold Hill	Coalmont	Cuchara	Galisteo	San Jose	Ypresian (IUCS) • Itaboraian (SALMA) Bumbanian (ALMA) • Mangaorapan (NZ)
Basin	Powder River Uinta Piceance Colorado Plateau Wind River Green River Bighorn	Piceance	Colorado Plateau	Wind River	Green River	Bighorn		Williston	Okanagan	Princeton	Buck Creek	Nechako	Sverdrup	Potomac	GoM	Laguna Salada	Rio Grande	North Park	Raton	Galisteo	San Juan	Coalmont Formation (North America)
Country	United States								Canada					United States		Mexico	United States
Copelemur
Coryphodon
Diacodexis
Homogalax
Oxyaena
Paramys
Primates
Birds
Reptiles
Fish
Insects
Flora
Environments	Alluvial-fluvio-lacustrine	Fluvial				Fluvial	Fluvio-lacustrine	Fluvial	Lacustrine		Fluvio-lacustrine		Deltaic-paludal	Shallow marine		Fluvial	Shallow marine	Fluvial		Fluvial		Wasatchian volcanoclastics Wasatchian fauna Wasatchian flora
Volcanic	Yes	No							Yes	No	Yes	No	Yes	No						Yes	No

See also

• Coalmont, Colorado
• List of fossiliferous stratigraphic units in Colorado
• Paleontology in Colorado

References

1. Hail, W.J. and Leopold, E.B., 1960. Paleocene and Eocene age of the Coalmont Formation, North Park, Colorado. Geological Survey Professional Paper, 400-B, pp.B260-B261.
2. Beekly, A.L., 1915. Geology and coal resources of North Park, Colorado. U.S. Geological Survey Bulletin, 596, 121 p
3. Coalmont Formation at Fossilworks.org
4. Cockerell, 1916
5. Cockerell, 1918
6. Brown, 1962

Bibliography

• Brown, R. W (1962), "Paleocene flora of the Rocky Mountains and Great Plains", United States Geological Survey Professional Paper , 375: 1–119
• Cockerell, T. D. A (1918), "New species of North American fossil beetles, cockroaches, and tsetse flies", Proceedings of the United States National Museum , 54 (2237): 301–311, doi:10.5479/si.00963801.54-2237.301
• Cockerell, T. D. A (1916), "Some American fossil insects", Proceedings of the United States National Museum , 51 (2146): 89–106, doi:10.5479/si.00963801.51-2146.89