View source for Earth:Wescogame Formation

{{Short description|Geological formation in the Grand Canyon}}
<!--{{for|the geologic fault of west Grand Canyon with the same name|Toroweap Fault}}-->
{{Infobox rockunit
| name  = Wescogame Formation
| image = Grandcanyon_view5.jpg
<!--| image = USA 09855 Grand Canyon Luca Galuzzi 2007.jpg-->
| imagesize = 265px
| caption = representative Supai Group 'redbeds'<br>(ridgeline extending north from South Rim, Grand Canyon)
| period = Pennsylvanian
<!--| age =  Lower Permian 287&nbsp;Ma-->
| age            = <br />Upper Pennsylvanian, <br />{{fossil range|312|300}}<ref>Blakey and Ranney (2008): '''300 Ma''' map, p. 39, '''312 Ma''', '''Manakacha Formation''' map, p. 33.</ref>
| type = Geologic unit
| prilithology = [[Earth:Sandstone|sandstone]], [[Earth:Siltstone|siltstone]]
| otherlithology =
| namedfor =
| namedby = <!--Ulrich, 1911-->
| region = [[Earth:Colorado Plateau|Colorado Plateau]], southwest and south
| coordinates = <!--{{Coord|34|00|N|97|00|W|region:US-OK_type:landmark_source:dewiki}}-->
| unitof = [[Earth:Supai Group|Supai Group]]
| subunits = <!--Mountain Lake Member, Pooleville Member-->
| overlies = Manakacha Formation, (2nd member)-Supai Group-312 Ma
| underlies = [[Earth:Esplanade Sandstone|Esplanade Sandstone]], (4th member)-Supai Group
| thickness = {{convert|200|ft|m|0}} max (100–200 ft typical)<!--{{convert|330|ft|m|sp=us}} approximate maximum<ref>Blakey and Ranney (2008) p. xviii.</ref>--><!--Pooleville Member at type location.<ref name="Fay">Fay, O. and A.A. Graffham. Biostratigraphic and paleontological studies. Echinoderm faunas from the Bromide Formation (Middle Ordovician) of Oklahoma: Lawrence, Kansas, University of Kansas Paleontological Institute Monograph 11 30–33 (1982)</ref>-->
| extent = Grand Canyon, Verde Valley, and basement rocks of [[Earth:Mogollon Rim|Mogollon Rim]] and central & east-northeast Arizona<!--from Blount to Decorah<ref name="Loeblich">Loeblich, A.R. jr. Bryozoa from the Ordovician Bromide Formation Oklahoma. Journal of Paleontology, 16-4 (1942)[http://www.jstor.org/pss/1298838]</ref>-->
| area =
| map =
| map_caption =
}}
The (Upper) Late Pennsylvanian '''Wescogame Formation''' is a [[Earth:Slope-former|slope-forming]], [[Earth:Sandstone|sandstone]], red-orange geologic unit, formed from an addition of [[Earth:Aeolian processes|eolian]] sand,<ref>Blakey and Ranney (2008) p. 40.</ref> added to [[Earth:Marine transgression|marine transgression]] deposits ([[Earth:Siltstone|siltstone]]s, etc.), and found throughout sections of the [[Earth:Grand Canyon|Grand Canyon]], in Arizona, Southwest United States. It is one of the upper members of the [[Earth:Supai Group|Supai Group]] 'redbeds' (member three of four major units), with the Supai Group found in other sections of Arizona, especially in the Verde Valley region, or as a basement unit below the [[Earth:Mogollon Rim|Mogollon Rim]], just eastwards or part of the basement Supai Group of the southwest & south [[Earth:Colorado Plateau|Colorado Plateau]].
<!--The Wescogame unit and Supai Group are dramatically exposed in northwest Arizona; the Supai Group and its four basic members are basement geologic units of the [[Earth:Colorado Plateau|Colorado Plateau]]'s southwest and south. In southeast Arizona, or at the southeast of the Mogollon Rim-[[Earth:White Mountains (Arizona)|White Mountains]] region the -->

Coeval units of Wescogame Formation and the Supai Group are replaced by geologic units formed from geology deposited in relationship to the former basin to the south-southeast in Arizona, the Pedregosa Basin, of the Pedregosa Sea, which extended northeast to the Verde Valley region, and the earlier deposition of the red rock sandstone of the [[Earth:Schnebly Hill Formation|Schnebly Hill Formation]], of the Sedona, Arizona region, (Oak Creek Canyon, Sycamore Canyon, and other related sub-regions).

==Geologic sequence==
The  Late Pennsylvanian-Early Permian geologic sequence of the Supai Group common in the Grand Canyon:<ref>Blakey and Ranney (2008) p. xviii.</ref> The Pennsylvanian is the Late Carboniferous.
* [[Earth:Supai Group|Supai Group]]
** 4 – [[Earth:Esplanade Sandstone|Esplanade Sandstone]]-(Early [[Earth:Permian|Permian]])
*** 3B – (Pakoon Limestone at west Grand Canyon & Nevada)
** 3 – Wescogame Formation-(Late Pennsylvanian)
** 2 – Manakacha Formation
** 1 – Watahomigi Formation

The Supai Group members were created from marine (oceanic) sequences of [[Earth:Marine transgression|marine transgression]], and regression, thus the alternating sandstone, siltstones, conglomerate subsections (facies); the subsections are not always a continuous transition into the above section, mostly due to ocean levels, falling, or rising, glaciation, or regional [[Subsidence|subsidence]]-(basins, etc.) or uplift of land. Today's Wasatch Front is the approximate lineage, NNE to SSW of the western coast region of North America from where the oceans transgressed. The ancient Antler Mountains-([[Earth:Antler orogeny|Antler orogeny]], off-shore volcanic island arch(es)), of ancient Nevada supplied material, from the west, off the 'ancestral' West Coast. The continent supplied material from the east, both directions supplying the offshore basin, the Cordilleran Basin which became part of the [[Earth:Basin and Range Province|Basin and Range Province]], in later epochs. Three other basins were involved in this history: southwest of the Ancestral Rocky Mountains was the Paradox Basin-(eastern Utah to Southwest Colorado), northeast was the Central Colorado Basin-(NW Colorado, NE Utah, SW Wyoming); the Oquirrh Basin was north-northwest, at present day northwest Utah.

===Supai Group and Hermosa Group, coeval units===
The approximate coeval [[Earth:Supai Group|Supai]] and Hermosa Groups, Arizona, Utah, and northwest Colorado:<ref>Blakey and Ranney (2008): ''"Geologic X-sections"'', (cross-sections), p. XVIII.</ref>

{| cellspacing=0 cellpadding=4 border=1
|- bgcolor="#ececec" style="text-align:center;"
!Arizona –<br>Grand Canyon & central-northeast AZ
!Utah – east & southeast
!Uncom-<br>compahgre<br>Uplift
!(northeast)-UT<br>(northwest)-CO<br>(proto)–[[Earth:Uintah Basin|Uintah Basin]] <br>region
|-
|'''[[Earth:Supai Group|Supai Group]]'''<br>~340–(330) to 285 Ma
|'''Hermosa Group'''
|'''"Ancestral Rocky Mtns"'''<br>(eroded to sea level, '''165 Ma''')<ref>Blakey and Ranney (2008): 165 Ma map: (upper)-Carmel Formation, with [[Earth:Sundance Sea|Sundance Sea]], pp. 76, 78.</ref>
|'''Hermosa Group'''
|-
|4 - [[Earth:Esplanade Sandstone|Esplanade Sandstone]]-(Grand Canyon & Verde Valley region)
|[[Earth:Cedar Mesa Sandstone|Cedar Mesa Sandstone]]
|"Ancestral Rocky Mtns"
|xxxxxxx
|-
|3B-Pakoon Limestone-(west)-Grand Canyon, & NV
|[[Earth:Elephant Canyon Formation|Elephant Canyon Formation]]-(east & southeast) Utah
|"Ancestral Rocky Mtns"
|Hermosa<br>members?
|-
|3-'''Wescogame Formation'''
|(Hermosa)
|"Ancestral Rocky Mtns"
|Hermosa<br>members?
|-
|2-Manakacha Formation
|(Hermosa)
|"Ancestral Rocky Mtns"
|Hermosa<br>members?
|-
|1-Watahomigi Formation
|(Hermosa)
|"Ancestral Rocky Mtns"
|Hermosa<br>members?
|-
!
!
!'''Uncom-'''<br>'''compahgre'''<br>'''Uplift'''
!
|-
|}

Because [[Earth:Marine transgression|marine transgression]]s cover distances, over time, the coeval units are separated by distance, and type of deposition material; the local subsidence, or uplift, as well as glaciation, and sea level changes, can cause variations in the deposition sequences of transgression-regressions. The ocean was to the west of the proto-North American continent, but also northwest, or southwest.

<gallery widths="245px" heights="185px" perrow=widths="245px" heights="185px" perrow="2">
File:USA 09855 Grand Canyon Luca Galuzzi 2007.jpg|'''Wescogame Formation''' slopes directly below upper-vertical-cliff of Esplanade Sandstone-(below [[Earth:Hermit Formation|Hermit Formation]] and white [[Earth:Coconino Sandstone|Coconino Sandstone]] prominence).<br>'''Isis Temple''', with complete [[Earth:Supai Group|Supai Group]] for Grand Canyon; (Pakoon Limestone miles westward in Grand Canyon, and Nevada)
File:USA 10052 Grand Canyon Luca Galuzzi 2007.jpg|Close-up of 'redbeds'
</gallery>

==Fossil footprints==
Fossil footprints were first discovered in the area in 1915 by Charles Schuchert.<ref name="dinotracksna-ageamphib-34" /> Charles Gilmore visited the Grand Canyon area during the 1920s to collect specimens of these footprints for the Smithsonian Institution.<ref name="dinotracksna-ageamphib-34" />  He also wanted to create an exhibit and interpretive center for [[Earth:Paleozoic|Paleozoic]] tracks like these at Hermit Trail.<ref name="dinotracksna-ageamphib-34" /> Lockley and Hunt (1995) described Gilmore's work as  "successful" and he ended by publishing several papers about the local footprints including those from the [[Earth:Early Permian|Early Permian]] Hermit Shale and the [[Earth:Middle Permian|Middle Permian]] [[Earth:Coconino Sandstone|Coconino Sandstone]].<ref name="dinotracksna-ageamphib-34" />

==See also==
* [[Earth:Marine transgression|Marine transgression]]

==References==

===Footnotes===
{{Reflist|3|refs=
<ref name="dinotracksna-ageamphib-34">"Western Traces in the 'Age of Amphibians'," Lockley and Hunt (1995); p. 34.</ref>

}}

===Bibliography===
* Blakey, and Ranney, 2008. ''Ancient Landscapes of the Colorado Plateau'', Ron Blakey, Wayne Ranney, c 2008, Grand Canyon Association (publisher), 176 pages, with Appendix, Glossary, Index. Contains approximately 75 shaded topographic maps, for geology, etc., with 54 (23 pairs, (46)) for [[Earth:Colorado Plateau|Colorado Plateau]] specifically; others are global, or North American.
* Lucchitta, 2001. ''Hiking Arizona's Geology,'' Ivo Lucchitta, c 2001, Mountaineers's Books. (softcover, {{ISBN|0-89886-730-4}})
<!--* Arizona DeLorme Atlas & Gazetteer, 5th Edition, c. 2002, 76 pages, pp.&nbsp;23, 24, 31, 32.
* Arizona Road & Recreation Atlas, Benchmark Maps, 2nd Edition, c. 1998, 112 pages, pp.&nbsp;28–29, 62–63.
* Chronic, Halka. ''Roadside Geology of Arizona,'' c. 1983, 23rd printing, Mountain Press Publishing Co. 322 pages. pp.&nbsp;229–232 –(''US 89A Marble Canyon – – Fredonia''), pp.&nbsp;179–180. (softcover, {{ISBN|978-0-87842-147-3}})
* Lockley, Martin  and Hunt, Adrian. '' Dinosaur Tracks of Western North America''. Columbia University Press. 1999.
* Lucchitta, 2001. ''Hiking Arizona's Geology,'' Ivo Lucchitta, c 2001, Mountaineers's Books. (softcover, {{ISBN|0-89886-730-4)}}-->

[[Category:Sandstone formations of the United States]]
[[Category:Colorado Plateau]]

{{Sourceattribution|Wescogame Formation}}