Mount Blanco

Coordinates: 33°47′29″N 101°15′11″W / 33.79139°N 101.25306°W / 33.79139; -101.25306

Mount Blanco
Landform
Mount Blanco viewed from above
Country	United States
State	Texas
County	Crosby
Region	Llano Estacado, West Texas
Location	Blanco Canyon
- elevation	937 m (3,074 ft)
- coordinates	33°47′29″N 101°15′11″W / 33.79139°N 101.25306°W / 33.79139; -101.25306
Geology	Blancan
Period	Quaternary
Epoch	Pleistocene
Location of Crosby County in Texas

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.^[1] It is the type locality of the Blanco Formation and Blancan Fauna, which occurs throughout North America.^[2][3]

Geology

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.^[4] 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.^[5] The thickness of the Blanco beds varies from around 22 to 26 m (72 to 85 ft) thick at the most.^[6] 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.

Fossil Fauna

All fossil fauna from Mount Blanco modified from Dalquest (1975) unless otherwise noted.^[7]

• Class Mammalia
  • Order Perissodactyla
    • Family Equidae
      • †Equus cumminsi
      • †Equus simplicidens
      • †Nannippus peninsulatus
  • Order Artiodactyla
    • Family Antilocapridae
    • Family Camelidae
      • †Blancocamelus meadei
      • †Camelops traviswhitei
      • †Canimartes cumminsi
    • Family Cervidae
      • †Odocoileus brachyodontus
    • Family Tayassuidae
      • †Platygonus biccalcaratus
      • †Titanotylopus spatulus
      • †Tanupolama blancoensis
  • Superorder Edentata
    • Family †Glyptodontidae
      • †Glyptotherium texanum
    • Family Megalonychidae
      • †Megalonyx leptostomus
    • Family †Mylodontidae
      • †Glossotherium chapadmalens
  • Order Lagomorpha
    • Family Leporidae
      • †Hypolagus sp.
      • †Nekrolagus progressus
  • Order Proboscidea
    • Family †Gomphotheriidae
      • †Stegomastodon mirificus
  • Order Carnivora
    • Family Canidae
      • †Borophagus diversidens
      • †Canis lepophagus
    • Family Felidae
      • †Felis cf. lacustris
      • †Dinofelis palaeoonca
      • †Homotherium
    • Family Hyaenidae
      • †Chasmaporthetes ossifragus
    • Family Mustelidae
      • †Canimartes cummins
      • †Spilogale rexroadi
  • Order Rodentia
    • Family Sciuridae
      • †Paenemarmota barbouri
      • Spermophilus sp.
      • †Spermophilius howelli
    • Family Geomyidae
      • Geomys sp.
    • Family Heteromyidae
      • †Perognathus parlettensis
      • †Perognathus rexroadensis
      • †Prodipomys centralis
    • Family Cricetidae
      • Baiomys sp.
      • †Bensonomys sp.
      • †Neotoma quadriplicatus
      • Onychomys sp.
      • † Peromyscus kansasensis
      • Reithrodontomys sp.
      • †Sigmodon medius
• Class Reptilia
  • Order Testudinata
    • Family Testudinidae
      • Geochelone sp.

Images

• 

  Early photo of Mount Blanco (1891)^[8]

• 

  Mount Blanco viewed from east (2002)

See also

• Blanco Canyon
• White River (Texas)
• Blancan
• Caprock Escarpment
• Yellow House Canyon
• Double Mountain Fork Brazos River
• Palo Duro Canyon

References

1. ^ 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.
2. ^ 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.
3. ^ 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.
4. ^ 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.
5. ^ 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.
6. ^ 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.
7. ^ Dalquest, W. W. 1975. Vertebrate Fossils from the Blanco Local Fauna of Texas. Occasional Papers The Museum Texas Tech University 30:1-52.
8. ^ 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.