Wescogame Formation |
| Usage of Geologic Unit Name: Wescogame Formation* of Supai Group |
| Age: Pennsylvanian, Late* Virgilian* |
| Geologic Province: Plateau sedimentary province* |
| Areal Extent: AZ(n)* |
| Type Locality: Type section: On Apache Trail east of Supai village. Named for Wescogame Point on west side of Havasu Canyon 3 mi southwest of Supai village, Grand Canyon, Coconino Co, AZ (McKee, 1975). |
|
Unit Name History: |
| Description from Grand Canyon Area (from Billingsley, George H., 2000) Wescogame Formation—Light-red, pale-yellow, and light-gray upper slope unit and lower cliff unit. Upper slope unit consists mainly of dark-red, fine-grained siltstone and mudstone interbedded with light-red, coarse-grained, calcareous sandstone and dolomitic sandstone, siltstone, mudstone, and conglomerate. Lower cliff unit consists mainly of light-red to gray, high-angle, large- and medium-scale, tabular-planar, cross-bedded sandstone and calcareous sandstone sets as much as 40 ft (12 m) thick. Includes interbedded dark-red, thin-bedded siltstone in upper part of cliff. Cross-bed sets contain large footprints of four-footed vertebrate animals in eastern part of map area. Unconformable contact with underlying Manakacha Formation marked by unconformity of erosion channels as much as 80 ft (24 m) deep in western part of map area, and less than 30 ft (10 m) deep in eastern part of map area. Channels commonly filled with limestone/chert conglomerate. The Wescogame thickens slightly from west to east, averaging about 130 ft (40 m) in western part of map area and about 150 ft (45 m) in eastern part Manakacha Formation—Light-red, white, and gray upper slope unit and lower cliff unit of sandstone, calcareous sandstone, dark-red siltstone, and gray limestone. Upper slope unit consists mainly of shaley siltstone and mudstone with minor interbedded, thin-bedded limestone and sandstone. Carbonate content of upper slope unit increases westward to form numerous ledge-forming, thin- and medium-bedded limestone beditors Upper slope unit is about 100 ft (30 m) thick in eastern half of map area, decreasing to less than 60 ft (18 m) thick in western half. Lower cliff unit is dominated by grayish-red, medium- to thick-bedded, crossbedded calcareous sandstone, dolomite, and sandy limestone. Lower cliff unit is about 60 ft (18 m) thick in eastern part of map area, thickening to about 100 ft (30 m) in western part. Carbonate content of lower cliff unit increases westward across map area, forming numerous gray limestone ledges. Unconformable erosional contact between the Manakacha and underlying Watahomigi Formation approximately marked at base of lower sandstone cliff of the Manakacha; erosional relief generally less than 3 ft (1 m) and wavy unconformable surface. Overall thickness averages about 200 ft (60 m) throughout map area. |
| References
McKee, E.H., 1975, The Supai Group; subdivision and nomenclature, IN Contributions to stratigraphy: U.S. Geological Survey Bulletin, 1395-J, p. J1-J7. McKee, E.D. (editor), 1982, The Supai Group of Grand Canyon: U.S. Geological Survey Professional Paper, 1173, 504 p. Santucci, Vincent L., and Hunt, Adrian P., 1998, Biostratigraphy and paleoecology of late Paleozoic tetrapod tracks from Grand Canyon National Park, Arizona: Journal of Vertebrate Paleontology, v. 18, no. 3, Supplement, p. 75. Schult, Mark F., 1995, Comparisons between the Las Cruces ichnofauna
and other Permian ichnofaunas, including inferred trackmakers: In, Early
Permian footprints and facies: Lucas, Spencer G., and Heckert, Andrew
B., New Mexico Museum of Natural History and Science Bulletin, vol.6,
p. 127-133. |
|
|
The URL is: https://gotbooks.miracosta.edu/gonp/coloradoplateau/lexicon/wescogame.htm Last modified: 1/7/2011 |