Khuff Formation
{{Short description|Geologic formation in the Middle East}}
{{Infobox rockunit
| name = Khuff Formation
| image =
| caption =
| type = Geological formation
| age = Middle Permian (?Capitanian) to early Triassic{{Geological range|Capitanian|Early Triassic|}}
|period = Permian
| prilithology =
| otherlithology =
| namedfor =
| region = Middle East
| coordinates =
| unitof = Akhdar Group
| subunits = From youngest to oldest:
- Khartam Member
- Midhnab Member
- Duhaysan Member
- Huqayl Member
- Ash Siqqah Member
| underlies = Sudair Formation
| overlies = Gharif Formation
| thickness = *171.4 m (562.2 ft) (type section)
| extent =
| area =
| map =
| map_caption =
}}
The Khuff Formation is a geologic formation in Oman and Saudi Arabia.{{Cite journal |last=Osterloff |first=Peter |last2=Al-Harthy |first2=Aida |last3=Penney |first3=Randall |last4=Spaak |first4=Pieter |last5=Williams |first5=Glen |last6=Al-Zadjali |first6=Farida |last7=Jones |first7=Neil |last8=Knox |first8=Robert |last9=Stephenson |first9=Michael |last10=Oliver |first10=Guy |last11=Al-Husseini |first11=Moujahed |date=January 2004 |title=Depositional sequences of the Gharif and Khuff Formations, subsurface Interior Oman |url=https://www.researchgate.net/publication/235697284 |journal=GeoArabia |language=English |pages=83–147}} It preserves fossils dating back to the Permian and early Triassic periods.{{Cite journal |last=Vaslet |first=Denis |last2=Le Nindre |first2=Yves-Michel |last3=Vachard |first3=Daniel |last4=Broutin |first4=Jean |last5=Crasquin-Soleau |first5=Sylvie |last6=Berthelin |first6=Martine |last7=Gaillot |first7=Jérémie |last8=Halawani |first8=Mohammed |last9=Al-Husseini |first9=Moujahed |date=2005-10-01 |title=The Permian-Triassic Khuff Formation of central Saudi Arabia |url=https://www.researchgate.net/publication/265522789 |journal=GeoArabia |language=en |volume=10 |issue=4 |pages=77–134 |doi=10.2113/geoarabia100477 |issn=1025-6059|doi-access=free }}
Stratigraphy
Depending on the author, various definitions and names for the members of the Khuff Formation have been proposed, which may lead to confusion. Vaslet et. al. (2005) defines the members as such (from oldest to youngest):
The Al Siqqah Member is the oldest of the members, tentatively dated to the middle Permian (Capitanian). It is 35 meters thick at the type section, becoming thinner to the southeast. It has previously been referred to as the Unayzah Formation or Unayzah Member.
The Huqayl Member has been dated to the late Permian (?Wuchiapingian) based on foraminifer assemblage. It ranges from 30 to 40 meters in thickness.
The Duhaysan Member is 13.4 meters thick at Jabal Duhaysan, and is believed to be late Permian (Wuchiapingian-Changhsingian) in age.
The Midhnab Member (or Midhnab Shale) is believed to date to the Changhsingian and is about 60 meters thick in the Ad Dawadimi quadrangle.
The Khartam Member (formerly the Khartam Limestone) is the youngest member, with the lower part dating to the latest Permian and the upper part to the early Triassic.
Depositional environment
The Khuff Formation was deposited on the outer shelf of the Arabian Platform and represents a shallow carbonate platform, with a coastline oriented northeast-southwest and facing the spreading Neotethys Ocean. The various units have been interpreted as lagoonal tidal sand flats or barrier beaches, outer-shelf conditions below storm wave base and deposition around storm wave base. The known fossil content supports the interpretation of the Khuff Formation as a marine environment. The presence of Tethyan brachiopods suggest a subtropical and warm climate, while cosmopolitan, endemic and Gondwanan brachiopod taxa indicate the area was open to outside influence, and the conodont fauna confirms a shallow marine habitat.{{Cite journal |last=Koot |first=Martha B. |last2=Cuny |first2=Gilles |last3=Tintori |first3=Andrea |last4=Twitchett |first4=Richard J. |date=2013-03-13 |title=A new diverse shark fauna from the Wordian (Middle Permian) Khuff Formation in the interior Haushi-Huqf area, Sultanate of Oman: CHONDRICHTHYANS FROM THE WORDIAN KHUFF FORMATION OF OMAN |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1475-4983.2012.01199.x |journal=Palaeontology |language=en |volume=56 |issue=2 |pages=303–343 |doi=10.1111/j.1475-4983.2012.01199.x|url-access=subscription }}{{Cite journal |last=Angiolini |first=Lucia |last2=Nicora |first2=Alda |last3=Bucher |first3=Hugo |last4=Vachard |first4=Daniel |last5=Pillevuit |first5=Alain |last6=Platel |first6=Jean-Pierre |last7=Roger |first7=Jack |last8=Baud |first8=Aymon |last9=Broutin |first9=Jean |last10=Al Hashmi |first10=Haroub |last11=Marcoux |first11=Jean |date=1998-11-30 |title=Evidence of a Guadalupian age for the Khuff Formation of southeastern Oman: Preliminary report |url=https://www.researchgate.net/publication/235007424 |journal=Rivista italiana di Paleontologia e Stratigrafia |language=en |volume=104 |issue=3 |pages=329–340 |doi=10.13130/2039-4942/5337}}
Fossil content
=Fish=
==Cartilaginous fish==
A large number of chondrichthyan dermal denticles are known from the formation.
class="wikitable" align="center" | ||||
colspan="7" align="center" | Cartilaginous fish reported from the Khuff Formation | ||||
---|---|---|---|---|
Genus | Species | Location
!Stratigraphic member !Material | Notes | Images |
Amelacanthus
|A. cf. sulcatus | |A ctenacanth. | | ||||
Anachronistidae?
|Gen. et. sp. indeterminate | |A potential anachronistid. | | ||||
Cooleyella
|C. cf. fordi | |An anachronistid. | | ||||
Deltodus
|D. aff. mercurei | |A cochliodontiform. | | ||||
Eugeneodontiformes?
|Gen. et. sp. indeterminate | |A likely eugeneodont. | | ||||
Euselachii incertae sedis
| | |A potential protacrodontid. | | ||||
rowspan="2" |Glikmanius
|G. culmenis | |A ctenacanth. | | ||||
G. cf. myachkovensis
| |A ctenacanth. | ||||
Gunnellodus
|G. bellistriatus | |A hybodont. | | ||||
rowspan="2" |Khuffia
|K. lenis | |A sphenacanthid. | | ||||
K. prolixa
| |A sphenacanthid. | | ||||
Nemacanthus
|N. sp. | |A palaeospinacid. | ||||
rowspan="3" |Omanoselache
|O. angiolinii | |A hybodont. | | ||||
O. hendersoni
| |A hybodont. | | ||||
cf. O. sp.
| |A hybodont. | | ||||
cf. 'Paleozoic Genus 1' sp.
| | |A hybodont, potential lochidiid. | | ||||
Petalodontiformes?
|Gen. et. sp. indeterminate | |Similar to Chomatodus. | | ||||
Reesodus
|R. underwoodi | |A hybodont. | | ||||
Solenodus
|S. cf. crenulatus | |A cochliodontiform. | | ||||
Teresodus
|T. amplexus | |A hybodont. | |
==Conodonts==
class="wikitable" align="center" | ||||
colspan="7" align="center" | Conodonts reported from the Khuff Formation | ||||
---|---|---|---|---|
Genus | Species | Location
!Stratigraphic member !Material | Notes | Images |
"Jinogondolella"
|"J." cf. altaduensis |A gondolellid. | |
=Invertebrates=
==Brachiopods==
class="wikitable" align="center" | ||||
colspan="7" align="center" | Brachiopods reported from the Khuff Formation | ||||
---|---|---|---|---|
Genus | Species | Location
!Stratigraphic member !Material | Notes | Images |
Kotlaia
|K. sp. ind. |An articulated specimen & a dorsal valve. |An enteletoid. | | ||||
rowspan="2" |Omanilasma
|O. desertica | |A terebratulidan. | | ||||
O. husseinii
|A terebratulidan. | |
==Cephalopods==
class="wikitable" align="center" | ||||
colspan="7" align="center" | Cephalopods reported from the Khuff Formation | ||||
---|---|---|---|---|
Genus | Species | Location
!Stratigraphic member !Material | Notes | Images |
rowspan="2" |Tirolonautilus
|T. feltgeni |South of Jabal al Amshiyah (Saudi Arabia).{{Cite journal |last=Chirat |first=Régis |last2=Vaslet |first2=Denis |last3=Le Nindre |first3=Yves-Michel |date=2006-01-01 |title=Nautiloids of the Permian-Triassic Khuff Formation, central Saudi Arabia |url=https://doi.org/10.2113/geoarabia110181 |journal=GeoArabia |volume=11 |issue=1 |pages=81–92 |doi=10.2113/geoarabia110181 |issn=1025-6059|doi-access=free }} |A tainoceratid nautiloid. | | ||||
T. hoernesi
|East of Safra ad Dumaythiyat (Saudi Arabia). |A tainoceratid nautiloid. | |
See also
{{Portal|Earth sciences|Oman|Saudi Arabia|Middle East|Paleontology}}
References
{{reflist}}
- {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org/|access-date= 29 July 2023|archive-date= 19 August 2022|archive-url= https://web.archive.org/web/20220819182839/https://www.fossilworks.org/|url-status= dead}}
{{coord missing|Oman}}