Griman Creek Formation

The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Cenomanian of the Late Cretaceous.[1] It is most notable for its fossils, including those of dinosaurs and primitive montremes, as well as being a major source of opal, both of which are found near Lightning Ridge, New South Wales[2]

Not to be confused with Gorman Creek Formation.

Griman Creek Formation Stratigraphic range: Early-mid Cenomanian ~99–96 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Rolling Downs Group
Sub-units	Coocoran Claystone & Wallangulla Sandstone Members
Underlies	Unconformity with Oligo-Miocene Cumborah Gravel
Overlies	Surat Siltstone, Wallumbilla Formation
Thickness	Up to 345 m (1,132 ft)
Lithology
Primary	Sandstone, siltstone, mudstone
Other	Conglomerate, coal
Location
Coordinates	29.4°S 147.7°E / -29.4; 147.7
Approximate paleocoordinates	64.4°S 134.9°E / -64.4; 134.9
Region	Queensland  New South Wales
Country	Australia
Extent	Surat Basin
Type section
Named for	Griman Creek
Named by	Reiser
Year defined	1970
Griman Creek Formation (Australia)

Description

As a whole, the formation primarily consists of thinly bedded medium to fine sandstone, siltstone and mudstone, with sporadic coal seams. In the vicinity of Lightning Ridge, it is divided up into two informal members the underlying Wallangulla Sandstone Member which primarily consists of red fine grained sandstone, light siltstone and grey claystone and is up to 30 metres (98 ft) thick while the overlying Coocoran Claystone consists of about 10 metres of claystone. The contact between the two units is sudden and unconformable. Discontinuous clay lens beds within the Wallangulla Sandstone Member near Lightning Ridge, referred to as the Finch Clay Facies, are one of Australia's primary sources of commercial precious opal, with many mines dug in the area. These deposits are also the primary source of fossils within the formation, a large proportion of which are preserved as semi-precious opalized pseudomorphs. The fauna found in lightning ridge indicates that the depositonal environment of the Finch Clay Facies was in near-coastal freshwater lagoons.[1]

Background

See also: Surat Basin

Paleogeography

late Early Cretaceous (105 Ma)

Australia was located near the South Pole in the Early and Middle Cretaceous
GPlates reconstruction for 100 Ma (Albian-Cenomanian and Early and Late Cretaceous boundary)

Paleogeography of the Turonian (90 Ma)
Original map by Ron Blakey

Fossil content

Indeterminate avialan, euornithopod, and sauropod remains that were once misidentified as brachiosaurid are present in New South Wales, Australia.[2] Euornithopod tracks are also present in New South Wales.

Mammals

Mammals
Genus	Species	Presence	Notes	Images
Kollikodon	K. ritchiei
Steropodon	S. galmani

Crocodyliformes

Crocodyliformes
Genus	Species	Presence	Notes	Images
Isisfordia	I. molnari	Lightning Ridge	Braincase and referred maxillary fragment[3]

Dinosaurs

Dinosaurs
Genus	Species	Presence	Notes	Images
Fostoria	F. dhimbangunmal	New South Wales	An iguanodont
Fulgurotherium	F. australe	New South Wales	[2]
Muttaburrasaurus	Indeterminate	New South Wales	[2]
Rapator	R. ornitholestoides	New South Wales	A megaraptoran; "Manual element"[2][4]
Walgettosuchus	W. woodwardi	New South Wales	"Vertebra"[2][5] Later determined to be an indeterminate theropod[2]
Weewarrasaurus	W. pobeni	New South Wales	An ornithopod known from an isolated dentary[6]
Ankylosauria	Indeterminate		Osteoderm[7]
Enantiornithes	Indeterminate		Partial femora
Megaraptora	Indeterminate	New South Wales	Partial skeleton including parts of the lower arm, claws, lower leg, part of the hip, and pieces of ribs.
Noasauridae	Indeterminate		Cervical vertebra[8]
Sauropoda	Indeterminate		A tooth

Pterosaurs

Pterosaurs
Genus	Species	Presence	Notes	Images
Anhangueria	Indeterminate		"two isolated tooth crowns", possible limb elements

Testudines

Turtles
Genus	Species	Presence	Notes	Images
Spoochelys	S. ormondea		Perichelydian stem-turtle[9][10]

See also

• List of dinosaur-bearing rock formations
• South Polar region of the Cretaceous
• Western Interior Seaway
• Cenomanian-Turonian extinction event
• Cenomanian formations

Australia

• Winton Formation, fossiliferous formation in Queensland
• Molecap Greensand, fossiliferous formation in Western Australia

South America

• Alcântara Formation, fossiliferous formation of the São Luís-Grajaú Basin, Brazil
• Candeleros and Lisandro Formation, fossiliferous formations of the Neuquén Basin, Argentima
• Cerro Fortaleza and Mata Amarilla Formation, fossiliferous formations of the Austral Basin
• Chipaque Formation, Cenomanian-Turonian source rock formation of the Altiplano Cundiboyacense and Llanos Basin, Colombia
• Kem Kem Beds, Cenomanian Lagerstätte in Morocco
  • Aoufous Formation
• Echkar Formation, fossiliferous formation of the Iullemmeden Basin, Niger

North America

• Cedar Mountain Formation
• Dakota Formation

Europe

• Cambridge Greensand, fossiliferous formation in England

Asia

• Burmese amber
• Sannine Formation, Lagerstätte in Lebanon, providing Lebanese amber
• Khodzhakul Formation, fossiliferous formation in Uzbekistan

References

1. Bell et al., 2019
2. Weishampel et al., 2004, pp.573-574
3. Hart et al., 2019
4. "Table 4.1," in Weishampel et al., 2004, p.74
5. "Table 4.1," in Weishampel et al., 2004, p.78
6. Bell et al., 2018
7. Bell et al., 2017
8. Brougham et al., 2020
9. T-Bone Extension, Coocoran Opal Fields at Fossilworks.org
10. Smith et al., 2013

Bibliography

• Bell, Phil R.; Federico Fanti; Lachlan J. Hart; Luke A. Milan; Stephen J. Craven; Thomas Brougham, and Elizabeth Smith. 2019. Revised geology, age, and vertebrate diversity of the dinosaur-bearing Griman Creek Formation (Cenomanian), Lightning Ridge, New South Wales, Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 514. 655–671. Accessed 2020-01-29. doi:10.1016/j.palaeo.2018.11.020
• Brougham, Tom; Elizabeth T. Smith, and Phil R. Bell. 2020. Noasaurids are a component of the Australian 'mid'-Cretaceous theropod fauna. Scientific Reports 10. 1428. Accessed 2020-01-29. doi:10.1038/s41598-020-57667-7 ISSN 2045-2322
• Hart, Lachlan J.; Phil R. Bell; Elizabeth T. Smith, and Steven W. Salisbury. 2019. Isisfordia molnari sp. nov., a new basal eusuchian from the mid-Cretaceous of Lightning Ridge, Australia. PeerJ 7. e7166. Accessed 2020-01-29. doi:10.7717/peerj.7166ISSN 2167-8359 PMC 6590469 PMID 31275756
• Bell, Phil R.; Matthew C. Herne; Tom Brougham, and Elizabeth T. Smith. 2018. Ornithopod diversity in the Griman Creek Formation (Cenomanian), New South Wales, Australia. PeerJ 6. e6008. Accessed 2020-01-29. doi:10.7717/peerj.6008 PMID 30533306 PMC 6284429
• Bell, Phil R.; Michael E. Burns, and Elizabeth T. Smith. 2017. A probable ankylosaurian (Dinosauria, Thyreophora) from the Early Cretaceous of New South Wales, Australia. Alcheringa: An Australasian Journal of Palaeontology 42. 120–124. Accessed 2017-10-23. doi:10.1080/03115518.2017.1384851 ISSN 0311-5518
• Smith, Elizabeth T, and Benjamin P. Kear. 2013. Spoochelys ormondea gen. et sp. nov., an Archaic Meiolaniid-Like Turtle from the Early Cretaceous of Lightning Ridge, Australia. Morphology and Evolution of Turtles Brinkman, Donald B.; Holroyd, Patricia A.; Gardner, James D.. 121–146. Accessed 2019-10-04. doi:10.1007/978-94-007-4309-0_9 ISBN 9789400743083
• Weishampel, David B.; Peter Dodson, and Halszka Osmólska (eds.). 2004. The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2