{{short description|Early Jurassic geological formation in the Mojave Desert, United States}} {{Infobox rockunit | name = Aztec Sandstone | image = RedRocksDistortedBeds.JPG | caption = Outcrop of the Aztec Sandstone at [[Red Rock Canyon National Conservation Area]] near Las Vegas, Nevada | type = [[Sedimentary Rock|Sedimentary]] | age = [[Early Jurassic]] | period = Early Jurassic | prilithology = [[sandstone]] | otherlithology = [[arenite]], [[sand]] | namedfor = | namedby = D. F. Hewett<ref name=Hewett1931>{{Cite Q| Q61823480|author= Hewett, D.F. |author-link=Donnel Foster Hewett}} (incl. geologic map, scale 1:62,500)</ref> | year_ts = 1931 | region = [[Mojave Desert]] | country = [[United States]] | coordinates = {{coord|35.4|N|115.5|W|display=inline,title}} | paleocoordinates = {{coord|20.8|N|53.4|W|display=inline}} | unitof = | subunits = | underlies = [[Willow Tank Formation]]<ref name=Longwell1949>{{Cite Q|Q60182382|author= Longwell, C.R.|author-link=Chester Ray Longwell}}</ref> | overlies = [[Chinle Formation]] | thickness = {{convert|2100|ft|m|abbr=on}} in Goodsprings quadrangle<ref name=Hewett1931/><br>{{convert|2500|ft|m|abbr=on}} in Muddy Mountain area<ref name=Longwell1949/> | extent = | area = Nevada,<ref name=Hewett1931/> Arizona, California<ref>Jennings, C.W., 1961, Geologic map of California; Kingman sheet: California Division of Mines and Geology, scale 1:250,000</ref> | map = {{Location map+ | United States#California | relief = 1 | width = 250 | float = center | places = {{Location map~ | United States#California | lat_deg = 35.4 | lon_deg = -115.5 | mark = Blue pog.svg | marksize = 10 }} {{Location map~ | United States#California | lat_deg = 36.4 | lon_deg = -114.6 | mark = Blue pog.svg | marksize = 10 }} }} | map_caption = }}

The '''Aztec Sandstone''' is an [[Early Jurassic]] geological [[Formation (geology)|formation]] of primarily [[Eolianite|eolian]] sand from which fossil [[pterosaur]] [[Trace fossil|tracks]] have been recovered.<ref name=FW>[https://paleobiodb.org/classic/displayStrata?geological_group=&formation=Aztec%20Sandstone&group_formation_member=Aztec%20Sandstone Aztec Sandstone] at [[Fossilworks]].org</ref> The formation is exposed in the [[Mojave Desert]] of [[Arizona]], [[California]] and [[Nevada]]. Aztec Sandstone is named after the Aztec Tank,<ref>{{Cite web |title=Geolex — Aztec publications |url=https://ngmdb.usgs.gov/Geolex/UnitRefs/AztecRefs_4626.html |access-date=2023-03-14 |website=ngmdb.usgs.gov}}</ref> a lake in the Spring Mountain region of Nevada.

== Description == The Aztec Sandstone is made up of two units. The lower resistant sandstone unit ({{convert|100|m|ft}} thick) is tan to off-white in outcrops but pinkish in fresh exposures. [[Cross-bedding|Cross-bedded]] 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 [[arenite]]s and red to brown silty sands.<ref name=FWMescal>[https://paleobiodb.org/classic/displayCollResults?collection_no=52175 Mescal Range] at [[Fossilworks]].org</ref>

== Vertebrate paleofauna == The formation has provided the following [[ichnofossil]]s attributed to vertebrates:<ref name=FW/>

{| class="wikitable" align="center" |- ! colspan="7" align="center" | '''[[Ichnofossil]]s of the Aztec Sandstone''' |- ! Genus !! Species !! Location !! Member !! Abundance !! Notes !! Images |- | style="background:#FEF6E4;" | ''[[Anchisauripus]]''<ref name="hiltonp26a">Listed as "cf. ''Anchisauripus''" in "Appendix: Summary of the Mesozoic Reptilian Fossils of California," Hilton (2003) p. 265</ref> | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | Reclassified as ''Grallator'' | |- | style="background:#FEF6E4;" | ''[[Brasilichnium]]'' | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | |- | style="background:#FEF6E4;" | ''[[Grallator]]''<ref name="hiltonp265g">Listed as "cf. ''Grallator''" in "Appendix: Summary of the Mesozoic Reptilian Fossils of California," in Hilton (2003) p. 265</ref> | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | [[File:Grallator.jpg|center|150px]] |- | style="background:#FEF6E4;" | ''[[Navahopus]]'' | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | |- | style="background:#FEF6E4;" | ''[[Octopodichnus]]'' | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | |- | style="background:#FEF6E4;" | ''[[Pteraichnus]]''<ref name="Lockleyetal2008">Lockley, et al. (2008)</ref> | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | |- | style="background:#FEF6E4;" | ''[[Skolithos]]'' | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | style="background:#FEF6E4;" | | [[File:Skolithos.jpg|center|150px]] |- |} {{paleobiota-key-compact}}

== See also == * [[List of fossil sites]] * [[List of fossiliferous stratigraphic units in California]] * [[List of fossiliferous stratigraphic units in Nevada]]

== References == {{reflist|2}}

=== Bibliography === {{commons category|Aztec Sandstone}} <!--most recent first--> * {{Cite Q| Q95597606|author=Bonde, J. W.|author2=Varricchio, D. J.|author3=Jackson, F. D.|author4=Loope, D. B.|author5=Shirk, A. M.|editor= E. M. Duebendorfer |editor2= E. I. Smith}} * Lockley, M.; Harris, J.D.; and Mitchell, L. 2008. "A global overview of pterosaur ichnology: tracksite distribution in space and time." ''Zitteliana''. B28. p.&nbsp;187-198. {{ISSN|1612-4138}}. * {{Cite Q| Q97000543|author= Porter, M.L.}} * 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

{{Chronostratigraphy of Nevada}}

[[Category:Geologic formations of Arizona]] [[Category:Geologic formations of California]] [[Category:Geologic formations of Nevada]] [[Category:Jurassic Arizona]] [[Category:Jurassic California]] [[Category:Jurassic geology of Nevada]] [[Category:Sandstone formations of the United States]] [[Category:Geologic formations with imbedded sand dunes]] [[Category:Aeolian deposits]] [[Category:Ichnofossiliferous formations]] [[Category:Paleontology in California]] [[Category:Paleontology in Nevada]]