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Carmel Formation

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Carmel Formation
Stratigraphic range:Bajocian–Callovian
Carmel Formation at its type location,Mount Carmel, Utah
TypeGeological formation
Unit ofSan Rafael Group
UnderliesEntrada Sandstone
OverliesNavajo Sandstone,Temple Cap Formation,Nugget Sandstone
ThicknessFrom 200 feet (60 m) to 1,000 feet (300 m)[1]
Lithology
PrimaryMudstone
OtherSandstone, siltstone, limestone
Location
Coordinates37°15′04″N112°39′47″W/ 37.251°N 112.663°W/37.251; -112.663
RegionWyoming, Utah, Colorado, north east Arizona and New Mexico
CountryUS
Type section
Named forMount Carmel
Named byGilluly and Reeside
Year defined1928
Carmel Formation is located in the United States
Carmel Formation
Carmel Formation (the United States)
Carmel Formation is located in Utah
Carmel Formation
Carmel Formation (Utah)
Carmel Formation exposed atGunlock Reservoir,southwestern Utah
Carmel Formation nearGunlock, Utah.The unconformably overlying dark unit is the Upper CretaceousIron Springs Formation.

TheCarmel Formationis ageologic formationin theSan Rafael Groupthat is spread across theU.S. statesofWyoming,Utah,Colorado,north eastArizonaandNew Mexico.Part of theColorado Plateau,this formation was laid down in theMiddle Jurassicduring the lateBajocian,through theBathonianand into the earlyCallovianstages.[2]

Description

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The Carmel Formation consists of up to 1,000 feet (300 m) ofmudrockandsandstoneinterbedded withlimestoneandgypsum.It was laid down in a shallow marine tosabkhaenvironment,[1]into whichterrigenous sedimentwas periodically carried. This gives the formation considerablelithologicalcomplexity.[3]The formation is underlain by theNavajo Sandstone,with the regional J-2unconformityseparating the two formations, or by theTemple Cap Formation.Portions of the Carmel Formation grade laterally eastward into thePage Sandstone.[2]The Carmel Formation in turn is overlain by theEntrada Formation.[3]

In the type area of southern Utah, the Carmel Formation is divided into the Judd Hollow Member, a basal limestone member; the Crystal Creek Member, mostly mudstone and siltstone, which grades into the Page Sandstone to the east; the Paria River Member, which is also siltstone and mudstone but is separated from the Crystal Creek Member by gypsum beds; and the Winsor Member, which is mudstone, sandstone, and siltstone separated from the Paria River by a basal limestone. Further east, the limestone marker bed pinches out, and the Winsor Member and Paria River Member become indistinguishable and are informally termed the upper member. The upper member containsvolcaniclasticbeds of rhyolite originating in avolcanic arcjust off the edge of theColorado Plateau.[4]

The formation preserves a Jurassichardground,rare for North America.[5]

Subunits

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Members (alphabetical):

  • Co-op Creek Limestone Member (UT) (in place of the preempted name Kolob Limestone Member)[6]
  • Crystal Creek Member (UT)[6]
  • Homestake Limestone Member (UT*)[7]
  • Judd Hollow Member (AZ*, UT*) or Judd Hollow Tongue (AZ*, UT*)[2]
  • Paria River Member (UT*)[8]
  • Wiggler Wash Member (UT*)[8]
  • Winsor Member (UT*)[8]

(Asterisks mean the name is used by theUS Geological Survey)[9]

History of investigation

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TheGolden Throne,arock formationinCapitol Reef National Park.Though the park is famous for whitedomesof theNavajo Sandstone,this dome's color is a result of a lingering section of yellow Carmel Formation carbonate, which has stained the underlying rock.

In 1928 Gilluly and Reeside stated an intent to name the formation after the village ofMount Carmel, Utahbut did not give atype locality.They noted it as a basal formation in theSan Rafael GroupinSan Rafael Swell,inEmery County, Utah.[10]An overview along with a type locality and source of name was stated by Gregory and Moore in 1931.[11]Mackin revised the formation's description and assigned the Homestake Limestone Member to it in 1954.[12]Harshbarger and others created an overview in 1957.[13]Its eastern areal limits were described by Wright and others in 1962.[14]In 1963, western areal limits along with an overview were completed by Schultz and Wright.[15]Another revision was done by Phoenix in 1963 who also added a Judd Hollow Tongue member.[16]Isotopic dating was conducted by Marvin and others in 1965. The Kolob, Crystal Creek, Paria River, Winsor, and Wiggler Wash members were assigned by Thompson and Stokes in 1970. Areal limits were adjusted by O'Sullivan and Craig in 1973[17]and again in 1983 by Blakey and others.[3]An overview was completed by Chapman in 1989.[4]Hintze and others conducted isotopic dating and created an overview in 1994.[18]

Paleontological finds

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There have been a number of paleontological finds within the Carmel Formation. Among these have beenbryozoans,[19]oysters,[5]anddinosaur footprints.[20]

Hardground mollusc community

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The formation preserves a rare Jurassic hardground interpreted as a carbonatelagoonbetweenooliticshoals and a subtidal zone. The hardground community was dominated bybivalvessuch asLiostrea,Plicatula,andModiolus.The ichnofossilGastro-chaenolitesis present, often with fossils ofLithophagapreserved inside. The rare bryozoanArachnidiumis found in attachment scars ofLiostrea.Though bivalves were abundant, the community is lacking in the diversity seen in other Jurassic hardgrounds, suggesting a restricted shelf environment.[5]

Bryozoans

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Bryozoans found within the Carmel Formation include seven species of calcareouscyclostomebryozoans as well as a soft-bodiedctenostomebryozoan.[19]

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  • Cross-section of a carbonate hardground encrusted by oysters and bored by bivalves (Gastrochaenolites)
    Cross-section of a carbonatehardgroundencrusted byoystersand bored bybivalves(Gastrochaenolites)
  • Biosparite/grainstone with crinoid columnals (Isocrinus nicoleti) from the Carmel Formation at Mount Carmel Junction, Utah.
    Biosparite/grainstone withcrinoidcolumnals (Isocrinus nicoleti) from the Carmel Formation atMount Carmel Junction,Utah.
  • Ripplemarks in a biosparite/grainstone from the Carmel Formation, southwestern Utah.
    Ripplemarks in abiosparite/grainstone from the Carmel Formation, southwestern Utah.
  • Ooids and crinoid columnals (Isocrinus nicoleti) on the surface of Carmel Formation limestone.
    Ooidsand crinoid columnals (Isocrinus nicoleti) on the surface of Carmel Formation limestone.
  • Ostreolith ("oyster ball") from the Carmel Formation, southwestern Utah.
    Ostreolith ( "oyster ball" ) from the Carmel Formation, southwestern Utah.
  • Trace fossil Gyrochorte from the Carmel Formation (Middle Jurassic) of SW Utah.
    Trace fossilGyrochortefrom the Carmel Formation (Middle Jurassic) of SW Utah.

Places found

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Geologic Province:[9]

References

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  1. ^ab"Carmel Formation (in San Rafael Group)".6 September 2015. Archived fromthe originalon 4 March 2016.Retrieved6 September2015.
  2. ^abcdefPeterson, F.; Pipiringos, G.N. (1979)."Stratigraphic relations of the Navajo Sandstone to Middle Jurassic formations, southern Utah and northern Arizona".United States Geological Survey Professional Paper.1035-B.doi:10.3133/pp1035B.
  3. ^abcBlakey, R.C.; Peterson, Fred; Caputo, M.V.; Voorhees, B.J.; Geddes, D.J.; Geesaman, R.C. (1983)."Paleogeography of Middle Jurassic continental, shoreline, and shallow marine sedimentation, southern Utah".Society of Economic Paleontologists and Mineralogists, Rocky Mountain Section, Rocky Mountain Paleogeography Symposium.2:77–100.Retrieved26 October2021.
  4. ^abChapman, Mary G. (1 March 1989). "Implications of rhyolitic ignimbrite boulders in the Middle Jurassic Carmel Formation of southern Utah".Geology.17(3): 281–284.doi:10.1130/0091-7613(1989)017<0281:IORIBI>2.3.CO;2.
  5. ^abcWilson, Mark A.; Palmer, Timothy J. (January 1994). "A carbonate hardground in the Carmel Formation (middle Jurassic, SW Utah, USA) and its associated encrusters, borers and nestlers".Ichnos.3(2): 79–87.doi:10.1080/10420949409386375.
  6. ^abDoelling, H.H.; Davis, F.D. (1989)."The geology of Kane County, Utah".Utah Geological and Mineral Survey Bulletin.124.Retrieved25 October2021.
  7. ^Leith, C.K.; Harder, E.C. (1908)."The iron ores of the Iron Springs district, southern Utah".United States Geological Survey Bulletin.338.doi:10.3133/b338.hdl:2346/64975.
  8. ^abcThompson, A.E.; Stokes, W.L. (1970). "Stratigraphy of the San Rafael Group, southwest and south central Utah".Utah Geological and Mineral Survey Bulletin.87.
  9. ^abGEOLEX database entry for Carmel, USGS(viewed 20 March 2006)
  10. ^Gilluly, J.; Reeside, J.B. Jr. (1928)."Sedimentary rocks of the San Rafael Swell and some adjacent areas in eastern Utah".United States Geological Survey Professional Paper.150-D: 73–76.doi:10.3133/pp150D.
  11. ^Gregory, H.C.; Moore, R.C. (1931)."The Kaiparowits Region: A Geographic and Geologic Reconnaissance of Parts of Utah and Arizona".United States Geological Survey Professional Paper.164:72–77.doi:10.3133/pp164.hdl:2027/uc1.32106006462755.
  12. ^Mackin, J.H. (1954). "Geology and iron ore deposits of the Granite Mountain area, Iron County, Utah".U.S. Geological Survey Miscellaneous Field Studies Map.MF-I4.doi:10.3133/mf14.
  13. ^Harshbarger, J.W.; Repenning, C.A.; Irwin, J.H. (1957)."Stratigraphy of the uppermost Triassic and the Jurassic rocks of the Navajo country".United States Geological Survey Professional Paper.291.doi:10.3133/pp291.
  14. ^Wright, J.C.; Shawe, D.R.; Lohman, S.W. (1962). "Definition of Members of Jurassic Entrada Sandstone in East-Central Utah and West-Central Colorado".AAPG Bulletin.46.doi:10.1306/BC74394B-16BE-11D7-8645000102C1865D.
  15. ^Schultz, L.G.; Wright, J.C. (1963)."Bentonite beds of unusual composition in the Carmel Formation, southwest Utah".U.S. Geological Survey Professional Paper.450-E (198): E67–E72.doi:10.3133/pp450E.
  16. ^Phoenix, D.A. (1963)."Geology of the Lees Ferry area, Coconino County, Arizona".United States Geological Survey Bulletin.1137:32–35.doi:10.3133/b1137.
  17. ^Marvin, R.F.; Wright, J.C.; Walthall, F.G. (1965)."K-Ar and Rb-Sr ages of biotite from the Middle Jurassic part of the Carmel Formation, Utah".United States Geological Survey Professional Paper.525-B: B104–B107.doi:10.3133/pp525B.
  18. ^Hintze, L.F.; Anderson, R.E.; Embree, G.F. (1994)."Geologic map of the Motoqua and Gunlock quadrangles, Washington County, Utah".U.S. Geological Survey Miscellaneous Investigations Series Map.I-2427.Retrieved26 October2021.
  19. ^abTaylor, Paul D.; Wilson, Mark A. (September 1999). "Middle Jurassic bryozoans from the Carmel Formation of southwestern Utah".Journal of Paleontology.73(5): 816–830.doi:10.1017/S0022336000040671.
  20. ^Lockley, Martin; Hunt, Adrian; Paquette, Marc; Bilbey, Sue-Ann; Hamblin, Alden (July 1998). "Dinosaur tracks from the Carmel formation, northeastern Utah: Implications for middle Jurassic paleoecology".Ichnos.5(4): 255–267.doi:10.1080/10420949809386424.
  21. ^abO'Sullivan, R.B.; Craig, L.C. (1973)."Jurassic rocks of northeast Arizona and adjacent areas"(PDF).New Mexico Geological Society Field Conference Guidebook.24:79–85.Retrieved25 October2021.
  22. ^Rowley, P.D.; Hansen, W.R. (1979)."Geologic map of the Plug Hat quadrangle, Moffat County, Colorado".U.S. Geological Survey Geologic Quadrangle Map.GQ-1514.Retrieved25 October2021.
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