Clayton Lake State Park is approximately 12 mi northwest of Clayton on NM–370 in northeastern New Mexico. Clayton Lake State Park lies on the northern edge of the Kiowa section of the Panhandle National Grasslands. The Clayton Lake earthen dam impounds water from Seneca Creek (also known as Cieneguilla Creek), a tributary of the Cimarron and Canadian Rivers. The dam is 92 ft high, 150 ft wide at the crest, and 150 ft long at the spillway.Clayton
Lake State Park offers a diverse geologic setting and is characterized by rolling hills, flat plains, and mesas that were intruded by numerous volcanoes forming lone mountain peaks and cones of various heights above the plains. The southern end of the Raton section is formed by the Canadian escarpment, north of the Canadian River. Basalt flows from the volcanoes protected the underlying sedimentary rocks from erosion and formed the tops of the mesas and flat plains. Clayton State Park is known for its dinosaur trackway.
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| Dinosaur trackway. Image © Steven W. Veatch, March 27, 2013 |
The basalt flows overlie the red to brown caliche sands of the Ogallala Formation of mid-Miocene to early Pliocene (4–12 million yrs ago) age. The Ogallala Formation is one of the most widespread units in the United States, extending from South Dakota to southern New Mexico and northwestern Texas, forming the Llano Estacado. The Ogallala Formation, the primary reservoir of ground water throughout the region, is responsible for man changing the appearance and character of the Great Plains. The Ogallala is 0–15 ft thick at Clayton Lake and consists of eolian sand and silt and fluvial sandy clay, siltstone, sandstone, and local gravel derived from the Rocky Mountains about 4–12 million yrs ago. Caliche beds are common throughout the unit. Caliche is composed of fractured and permeable deposits of gravel, sand, silt, and clay that is cemented by calcium carbonate.
The Ogallala Formation unconformably overlies the Cretaceous Graneros Shale, which forms covered slopes in the park. The Graneros Shale is predominantly gray shale found in local arroyo cuts and was deposited by the Cretaceous marine sea about 97.5– 91 million yrs ago. Local invertebrate microfossils shaped like grains of rice, called Foraminifera, are found in the shale beds and confirm the Late Cretaceous (Cenomanian) age.
The Graneros Shale unconformably overlies the Cretaceous Dakota Group. The Romeroville Sandstone, the upper unit of the Dakota Group, consists of a thick quartzose sandstone unit that forms the lowest benches along the lake. It is yellowish orange to brown, fine to coarse grained, poor to well sorted, and bioturbated. Crossbeds and ripple marks are common locally, indicating fluvial deposition. Most of the beds surrounding the lake and above the spillway belong to the Romeroville Sandstone.
The Romeroville Sandstone overlies the Pajarito Shale. The Pajarito Shale, the middle unit of the Dakota Group, is approximately 12 ft thick and consists of interbedded gray silty shale, shaly siltstone, and quartzose sandstone. The upper two horizons of dinosaur footprints are in the Pajarito Shale. The Pajarito Shale overlies the Mesa Rica Sandstone, the basal unit of the Dakota Group. The Mesa Rica Sandstone is approximately 40 ft thick and consists of grayish-orange, medium- to coarse-grained, poorly sorted, quartzose sandstone. Local beds contain crossbeds and ripple marks, indicating fluvial deposition. This unit also contains the stratigraphically lowest horizon (oldest) of dinosaur footprints. It overlies a micaceous shale belonging to the Cretaceous Glencairn Shale.
The most exciting geological feature at Clayton Lake State Park is the dinosaur footprints found in sandstone at the dam spillway about 1982. Approximately 500 tracks of at least three species are found at the spillway; most of them pertain to ornithopod dinosaurs (ichnogenus Caririchnium) and theropods. The dinosaurs ranged in size from a baby Iguanodont that was approximately 1 ft long to adults that were 30 ft long. Most of the tracks are of bipedal herbivores or planteaters (Iguanodonts or Hadrosaurs). The kite-shaped tracks were made by Iguanodonts walking in wet mud, Worm borrows, fossilized impressions of plants, ripple marks from waves, and mudcracks are also common.
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| Large trace fossil. Possible worm. Image © Steven W. Veatch, March 27, 2013 |
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| Worms going in all directions. Image © Steven W. Veatch, March 27, 2013 |
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| Sedimentary structure: Image © Steven W. Veatch, March 27, 2013 |
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| Sedimentary structures: Image © Steven W. Veatch, March 27, 2013 |
These tracks present excellent examples of the behavior of the dinosaurs. One set of prints was made by a swimming crocodile. Individual dinosaur tracks are along a single line, indicating that the dinosaur walked with his legs beneath him and not out to the side like modern reptiles. At one spot, the tracks suggest that a large planteater slipped in the mud and used his tail to keep his balance.
Earlier studies suggested that the host rocks belonged to the Romeroville Sandstone, but more detailed studies showed that the host rocks belong to the Pajarito Shale and underlying Mesa Rica Sandstone, both of which are older than the Romeroville. These stratigraphic studies suggest that the footprints are about 91–100 million yrs old.
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| Unusual track. Red lines indicate what some say is a tail mark. Image © Steven W. Veatch, March 27, 2013 |
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| Theropod track. Image © Steven W. Veatch, March 27, 2013 |
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| Theropod track. Image © Steven W. Veatch, March 27, 2013 |
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| Large dinosaur track with gol nugget washed out from melting New Mexico snows. Image © Steven W. Veatch, March 27, 2013 |
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| An example of "dinoturbation." Image © Steven W. Veatch, March 27, 2013 |
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| Two tracks that are different than the others. Image © Steven W. Veatch, March 27, 2013 |
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| More tracks. All dino. Image © Steven W. Veatch, March 27, 2013 |
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| Dino tracks by impoundment. Image © Steven W. Veatch, March 27, 2013 |
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| View of Clayton Lake VImage © Steven W. Veatch, March 27, 2013 |
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| Another view of the lake. Image © Steven W. Veatch, March 27, 2013 |
Note: text from New Mexico Bureau of Geology and Minerals
References
Baldwin, B., and Muehlberger, W. R., 1959, Geologic studies of Union County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 63, 171 pp.
Folsom, F., 1974, An amateur’s bonanza: discovery of early man in North America: The American West, v. 11, no. 6, pp. 34–39.
Foster, R., 1983, Clayton Lake: New Mexico Geology, v. 5, pp. 81–82.
Frye, J. C., Leonard, A. B., and Glass, H. D., 1978, Late Cenozoic sediments, molluscan faunas, and clay minerals in northeastern New Mexico: New Mexico Bureau of Mines and Mineral Resources, Circular 160, 32 pp.
Hawley, J. W., 1984, The Ogallala Formation in eastern New Mexico: Texas Tech University, Water Resources Center, Proceedings of the Ogallala Aquifer Symposium II, pp. 157–176.
Hunt, A. P., and Lucas, S. G., 1996, A reevaluation of the vertebrate Ichnofauna of the Mesa Rica Sandstone and Pajarito Formations (Lower Cretaceous: Late Albian), Clayton Lake State Park, New Mexico (abs.): New Mexico Geology, v. 18, no. 2, p. 57.
Julyan, R., 1996, The place names of New Mexico: University of New Mexico Press, Albuquerque, 385 pp.
Lucas, S. G., 1990, Type and reference sections of the Romeroville Sandstone (Dakota Group), Cretaceous of northeastern New Mexico; in Bauer, P. W., Lucas, S. G., Mawer, C. K., and McIntosh, W. C. (eds.), Tectonic development of the southern Sangre de Cristo Mountains, New Mexico: New Mexico Geological Society, Guidebook 41, pp. 323–326.
Lucas, S. G., Hunt, A. P., Kietzke, K. K., and Wolberg, D. L., 1986, Cretaceous stratigraphy and biostratigraphy, Clayton Lake State Park, Union County, New Mexico: New Mexico Geology, v. 8, pp. 60–65.
McGrath, D. A., and Hawley, J. W., 1985, Calcretes of the Santa Rosa area; in Lucas, S. G., and Zidek, J. (eds.), Santa Rosa–Tucumcari Region : New Mexico Geological Society, Guidebook 36, pp. 4–6.
Reeves, C. C., Jr., 1971, Relations of caliche to small natural depressions, southern High Plains, Texas and New Mexico: Geological Society of America, Bulletin, v. 82, pp. 1983–1988.
Scott, G. R., 1986, Geologic and structure contour map of the Springer 30’x 60’ quadrangle, Colfax, Harding, Mora, and Union Counties, New Mexico: U.S. Geological Survey, Map I–1705, 2 sheets, scale 1:100,000.
Stormer, J. C., Jr., 1972, Ages and nature of volcanic activity on the southern High Plains, New Mexico and Colorado: Geological Society of America, Bulletin, v. 83, pp. 2443–2448.
Young, J. V., 1984, The State Parks of New Mexico: University of New Mexico Press, Albuquerque, 160 pp.
Special note: just kidding about the gold nugget washing into the foot print of the Mesozoic dinosaur track.
