Aztec Sandstone
| Aztec Sandstone | |
|---|---|
| Stratigraphic range: Early Jurassic | |
 Outcrop of the Aztec Sandstone at Red Rock Canyon National Conservation Area near Las Vegas, Nevada | |
| Type | Sedimentary |
| Underlies | Willow Tank Formation[1] |
| Overlies | Chinle Formation |
| Area | Nevada,[2] Arizona, California[3] |
| Thickness | 2,100 ft (640 m) in Goodsprings quadrangle[2] 2,500 ft (760 m) in Muddy Mountain area[1] |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Coordinates | 35°24′N 115°30′W / 35.4°N 115.5°W |
| Approximate paleocoordinates | 20°48′N 53°24′W / 20.8°N 53.4°W |
| Region | Mojave Desert |
| Country |  United States |
| Type section | |
| Named by | D. F. Hewett[2] |
| Year defined | 1931 |
  Aztec Sandstone (the United States)  Aztec Sandstone (California) | |
The Aztec Sandstone is an Early Jurassic geological formation of primarily eolian sand from which fossil pterosaur tracks have been recovered.[4] The formation is exposed in the Mojave Desert of Arizona, California and Nevada.
Description
The Aztec Sandstone is made up of two units. The lower resistant sandstone unit (100 metres (330 ft) thick) is tan to off-white in outcrops but pinkish in fresh exposures. Crosbedded lenses can easily be observed. Frosted and pitted quartz grains well-cemented by silica are described by Evans in 1958 and 1971. The upper and less resistant unit (200m thick) consists of alternating white quartz arenites and red to brown silty sands.[5]
Vertebrate paleofauna
The formation has provided the following ichnofossils attributed to vertebrates:[4]
| Ichnofossils of the Aztec Sandstone | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Member | Abundance | Notes | Images |
| Anchisauripus[6] | Reclassified as Grallator | |||||
| Brasilichnium | ||||||
| Grallator[7] |  | |||||
| Navahopus | ||||||
| Octopodichnus | ||||||
| Pteraichnus[8] | ||||||
| Skolithos |  | |||||
Color key
|
Notes Uncertain or tentative taxa are in small text; |
See also
- List of fossil sites
- List of fossiliferous stratigraphic units in California
- List of fossiliferous stratigraphic units in Nevada
References
- ^ a b Longwell, C.R., 1949, Structure of the northern Muddy Mountain area, Nevada: Geological Society of America Bulletin, v. 60, no. 5, p. 923-967.
- ^ a b c Hewett, D.F., 1931, Geology and ore deposits of the Goodsprings quadrangle, Nevada: U.S. Geological Survey Professional Paper, 162, 172 p., (incl. geologic map, scale 1:62,500)
- ^ Jennings, C.W., 1961, Geologic map of California; Kingman sheet: California Division of Mines and Geology, scale 1:250,000
- ^ a b Aztec Sandstone at Fossilworks.org
- ^ Mescal Range at Fossilworks.org
- ^ Listed as "cf. Anchisauripus" in "Appendix: Summary of the Mesozoic Reptilian Fossils of California," Hilton (2003) p. 265
- ^ Listed as "cf. Grallator" in "Appendix: Summary of the Mesozoic Reptilian Fossils of California," in Hilton (2003) p. 265
- ^ Lockley, et al. (2008)
Bibliography
Wikimedia Commons has media related to Aztec Sandstone.
- J. W. Bonde, D. J. Varricchio, F. D. Jackson, D. B. Loope, and A. M. Shirk. 2008. Dinosaurs and dunes! Sedimentology and paleontology of the Mesozoic in the Valley of Fire State Park. In E. M. Duebendorfer & E. I. Smith (ed.), Field Guide to Plutons, Volcanoes, Faults, Reefs, Dinosaurs, and Possible Glaciation in Selected Areas of Arizona, California, and Nevada: Geological Society of America Field Guide 11:249-262
- Lockley, M.; Harris, J.D.; and Mitchell, L. 2008. "A global overview of pterosaur ichnology: tracksite distribution in space and time." Zitteliana. B28. p. 187-198. ISSN 1612-4138.
- Porter, M.L., 2006. Sedimentology of an ancient erg margin: the Lower Jurassic Aztec Sandstone, southern Nevada and southern California. Sedimentology 34:661-680.
- Hilton, Richard P. 2003. Dinosaurs and Other Mesozoic Reptiles of California. Berkeley: University of California Press. 318 pp.
Further reading
- R. E. Reynolds. 1986. California trackways from the Lower Jurassic Aztec Sandstone. In D. D. Gillette (ed.), First International Symposium on Dinosaur Tracks and Traces. Abstracts with Program 24
Categories:
- Geologic formations of Arizona
- Geologic formations of California
- Geologic formations of Nevada
- Jurassic Arizona
- Jurassic California
- Jurassic geology of Nevada
- Sandstone formations of the United States
- Geologic formations with imbedded sand dunes
- Aeolian deposits
- Ichnofossiliferous formations
- Paleontology in California
- Paleontology in Nevada