Mount Blanco is a small white hill — an erosional remnant — located on the eastern border of the Llano Estacado within Blanco Canyon in Crosby County, Texas. It is the type locality of the Blanco Formation and Blancan Fauna, which occurs throughout North America.
Mount Blanco viewed from above
|Elevation||3,074 ft (937 m)|
|Age of rock||Blancan, Quaternary|
The term "Blanco Canyon beds", later shortened to "Blanco beds", was first applied to this formation in 1890 by William F. Cummins of the Geological Survey of Texas. The Blanco beds are considered to be of lacustrine origin – deposited in a Pleistocene lake basin set in the Ogallala formation of Pliocene age which underlies the upper surface sediments of the Llano Estacado. The thickness of the Blanco beds varies from around 22 to 26 m (72 to 85 ft) thick at the most. The formation mainly consists of light-gray fine-grained mudstone, sandstone, and some conglomerate. These light-colored sediments contrast sharply with the rust-colored sediments of the Ogallala Formation.
All fossil fauna are from Mount Blanco modified from Dalquest (1975) unless otherwise noted.
- Class Mammalia
- Order Perissodactyla
- Order Artiodactyla
- Superorder Edentata
- Order Lagomorpha
- Order Proboscidea
- Order Carnivora
- Order Rodentia
- Family Sciuridae
- †Paenemarmota barbouri
- Spermophilus sp.
- †Spermophilius howelli
- Family Geomyidae
- Geomys sp.
- Family Heteromyidae
- †Perognathus parlettensis
- †Perognathus rexroadensis
- †Prodipomys centralis
- Family Cricetidae
- Family Sciuridae
- Class Reptilia
Early photo of Mount Blanco (1891)
- Holliday, V.T. 1988. Mt. Blanco revisited: soil-geomorphic implications for the ages of the Upper Cenozoic Blanco and Blackwater Draw Formations. Geology 16(6):505-508.
- Cope, E.D. 1892. A contribution to a knowledge of the fauna of the Blanco beds of Texas. Proceedings of the Academy of Natural Sciences of Philadelphia 44:226-229.
- Schultz, G.E. 1977. Blancan and post-Blancan faunas in the Texas Panhandle. In: Schultz, G.E. (ed), Guidebook: Field conference on late Cenozoic biostratigraphy of the Texas Panhandle and adjacent Oklahoma: West Texas State University, Kilgore Research Center, Special Publication 1, pp. 105-145.
- Cummins, W.F. 1890. The Permian of Texas and its overlying beds. In: Dumble, E.T. (ed), First annual report of the Geological Survey of Texas 1889, pp. 183-197.
- Izett, G.A., Wilcox, R.E., and Borchardt, G. 1972. Correlation of a volcanic ash bed in Pleistocene deposits near Mount Blanco, Texas, with the Guaje Pumice Bed of the Jemez Mountains, NM. Quaternary Research 2:554-578.
- Evans, G.L. 1948. Geology of the Blanco beds of West Texas. In: Colbert, E.H. (ed), Pleistocene of the Great Plains (symposium). Geological Society of America Bulletin No. 59, pp. 617-619.
- Dalquest, W. W. 1975. Vertebrate Fossils from the Blanco Local Fauna of Texas. Occasional Papers The Museum Texas Tech University 30:1-52.
- Cummins, W.F. 1892. Report on the geography, topography, and geology of the Llano Estacado or Staked Plains. In: Dumble, E.T. (ed), Third annual report of the Geological Survey of Texas 1891, pp. 129-223.