Canutillo Formation
{{Short description|Geologic formation in Texas, US}}
{{Infobox rockunit
| name = Canutillo Formation
| image =
| caption =
| type = Formation
| age = Middle Devonian
| period = Middle Devonian
| prilithology = Siltstone
| otherlithology = Shale
| namedfor = Canutillo, Texas
| namedby = L.A. Nelson
| year_ts = 1940
| region = Texas
| country = United States
| coordinates = {{coord|31.92|N|106.50|W|display=inline}}
| unitof =
| subunits =
| underlies = Percha Formation
| overlies = Fusselman Formation
| thickness = {{convert|15|feet|meters}}
| extent =
| area =
| map = {{Location map+ | United States#Texas
| relief = 1
| width = 250
| float = center
| places =
{{Location map~ | United States#Texas
| lat_deg = 31.92
| lon_deg = -106.50
| mark = Brown pog.svg
| marksize = 12
}}
}}
| map_caption =
}}
The Canutillo Formation is a geologic formation that is exposed in the Franklin Mountains near El Paso, Texas. The formation is Middle Devonian in age.{{cite journal |last1=Laudon |first1=Lowell R. |last2=Bowsher |first2=Arthur L. |title=Mississippian formations of southwestern New Mexico |journal=Geological Society of America Bulletin |date=1949 |volume=60 |issue=1 |pages=1 |doi=10.1130/0016-7606(1949)60[1:MFOSNM]2.0.CO;2}}{{cite journal |last1=Ludington |first1=Steve |last2=Hanna |first2=W.F. |last3=Turner |first3=R.L. |last4=Jeske |first4=R.E. |title=Mineral resources of the Organ Mountains Wilderness Study Area, Dona Ana County, New Mexico |journal=U.S. Geological Survey Bulletin |date=1988 |volume=1735-D |doi=10.3133/b1735D|hdl=2027/osu.32435022084842 |hdl-access=free }}
Description
The Canutillo Formation consists of about {{convert|15|feet|meters}} of soft gray siltstone. It is unconformably overlain by the Percha Formation. The Canutillo Formation likely correlates with the Onate Formation.
Fossils
The formation is fossiliferous, but few fossils are time diagnostic. Fossils include abundant Leiorhynchus and other brachiopods and a few pelecypods.
History of investigation
The formation was first described in his dissertation by L.A. Nelson in 1937 for outcrops in the Franklin Mountains. Nelson assigned all beds between the Silurian Fusselman Formation and the Mississippian Helms Formation to the Canutillo.{{cite journal |last1=Nelson |first1=L.A. |year=1937 |title=Gastropoda from the Pennsylvanian (Magdalena) of the Franklin Mountains of west Texas [abstract of thesis] |journal=Colorado University Studies |volume=25 |number=1 |pages=89–91.}} Nelson formally published the definition in 1940 and extended the outcrop range to the Hueco Mountains.{{cite journal |last1=Nelson |first1=L.A. |title=Paleozoic Stratigraphy of Franklin Mountains, West Texas |journal=AAPG Bulletin |date=1940 |volume=24 |issue=1 |pages=157–172 |doi=10.1306/3D93319A-16B1-11D7-8645000102C1865D}} In 1945, F.V. Stevenson restricted the formation to the Franklin Mountains.{{cite journal |last1=Stevenson |first1=Frank V. |title=Devonian of New Mexico |journal=The Journal of Geology |date=July 1945 |volume=53 |issue=4 |pages=217–245 |doi=10.1086/625283}} In 1949, Lowell R. Laudon and Arthur L. Bowshwer restricted the formation to a sequence of just {{convert|15|feet|meters}} of soft gray siltstone.
See also
{{Portal |Earth sciences|Paleontology}}
Footnotes
{{Reflist}}
{{Use mdy dates|date=May 2023}}
Category:Devonian southern paleotemperate deposits