Griman Creek Formation

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Griman Creek Formation
Stratigraphic range: late Albian-early-mid Cenomanian
~106–98  Ma
Type Geological formation
Unit of Rolling Downs Group
Sub-unitsCoocoran Claystone & Wallangulla Sandstone Members
Underlies Unconformity with Oligo-Miocene Cumborah Gravel
Overlies Surat Siltstone, Wallumbilla Formation
ThicknessUp to 345 m (1,132 ft)
Lithology
Primary Sandstone, siltstone, mudstone
Other Conglomerate, coal
Location
Coordinates 29°24′S147°42′E / 29.4°S 147.7°E / -29.4; 147.7
Approximate paleocoordinates 64°24′S134°54′E / 64.4°S 134.9°E / -64.4; 134.9
RegionQueensland
New South Wales
CountryAustralia
Extent Surat Basin
Type section
Named forGriman Creek
Named byReiser
Year defined1970
Australia relief map.jpg
Green pog.svg
Griman Creek Formation (Australia)

The Griman Creek Formation is a geological formation in northern New South Wales and southern Queensland, Australia whose strata date back to the Albian-Cenomanian stages of the mid-Cretaceous. [1] It is most notable being a major source of opal, found near the town of Lightning Ridge, New South Wales. Alongside the opal opalised fossils are also found, including those of dinosaurs and primitive monotremes. [2]

Contents

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 depositional environment of the Finch Clay Facies was in near-coastal freshwater lagoons. [1]

Background

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) Geology of Asia 100Ma.jpg
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 90 Ma - Late Cretaceous paleogeography with known distribution of Arcellites disciformis indicated.jpg
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.[ citation needed ]

Dipnoi

Dipnoi of the Griman Creek Formation
TaxaSpeciesPresenceMaterialNotesImages
Ceratodus [3] C. diutinusIsolated tooth plates
Metaceratodus [3] M. wollastoniIsolated tooth plates
Neoceratodus [4] N. potkoorokiIsolated tooth plates

Actinopterygii

Actinopterygians of the Griman Creek Formation
TaxaSpeciesPresenceMaterialNotesImages
Calamopleurus ? [4] sp.Isolated jaw bones

Mammals

Monotremes

Mammals
GenusSpeciesPresenceMaterialsNotesImages
Dharragarra [5] D. auroraA partial left mandibular ramus.A monotreme.
Kollikodon [5] K. ritchieiAn opalised dentary fragment, with one premolar and two molars in situ, as well as a referred maxillary fragment containing the last premolar and all four molarsA monotreme.
Opalios [5] O. splendensA fragmentary left dentary.A monotreme.
Parvopalus P. clytieiA partial left dentary.A monotreme.
Steropodon S. galmaniA monotreme
Steropodon BW.jpg
Stirtodon S. elizabethaeA large isolated premolars.A monotreme

Crocodyliformes

Crocodyliformes
GenusSpeciesPresenceMaterialsNotesImages
Isisfordia I. molnariLightning RidgeBraincase and referred maxillary fragment [6] A crocodyliform.
Isisfordia.jpg

Dinosaurs

Indeterminate ornithopods and iguanodontians are known from the formation. [1] Indeterminate avetheropods and megaraptorans are known from the formation. [1] Two species of titanosauriforms and one species of titanosaur are known from teeth. [7]

Dinosaurs
GenusSpeciesPresenceNotesImages
Fostoria F. dhimbangunmalNew South WalesA member of Rhabdodontomorpha.
Fulgurotherium F. australeNew South Wales [2]
Rapator R. ornitholestoidesNew South WalesA megaraptoran; "Manual element" [2] [8]
Rapator.png
Walgettosuchus W. woodwardiNew South Wales"Vertebra" [2] [9]
Later determined to be an indeterminate theropod [2]
Walgettosuchus.png
Weewarrasaurus W. pobeniNew South WalesAn ornithopod known from an isolated dentary [1]
Ankylosauria IndeterminateOsteoderm [10]
Enantiornithes IndeterminatePartial femora[ citation needed ]
Megaraptora ("Lightning Claw")IndeterminateNew South WalesPartial skeleton including parts of the lower arm, claws, lower leg, part of the hip, and pieces of ribs. [11]
Noasauridae IndeterminateCervical vertebra [12]
Sauropoda IndeterminateA tooth

Pterosaurs

Pterosaurs
GenusSpeciesPresenceNotesImages
Anhangueria Indeterminate"two isolated tooth crowns", possible limb elements[ citation needed ]

Testudines

Turtles
GenusSpeciesPresenceNotesImages
Spoochelys S. ormondea Perichelydian stem-turtle [13] [14]
Chelidae Indeterminate [15]

See also

References

  1. 1 2 3 4 5 Bell et al. 2019.
  2. 1 2 3 4 5 6 Weishampel, Dodson & Osmólska 2004, pp. 573–574.
  3. 1 2 Kemp, A. (1997). "Four species of Metaceratodus (Osteichthyes: Dipnoi, Family Ceratodontidae) from Australian Mesozoic and Cenozoic deposits". Journal of Vertebrate Paleontology . 17 (1): 26–33. doi:10.1080/02724634.1997.10010949. ISSN   0272-4634. Wikidata   Q104114935.
  4. 1 2 Berrell, Rodney W.; Cavin, Lionel; Trinajstic, Kate; Boisvert, Catherine; Smith, Elizabeth T. (August 2023). "The first record of amiid fishes (Halecomorphi, Amiiformes, Amiidae, Calamopleurini?) from Eastern Gondwana". Cretaceous Research. 148: 105538. Bibcode:2023CrRes.14805538B. doi:10.1016/j.cretres.2023.105538.
  5. 1 2 3 Flannery, Timothy F.; McCurry, Matthew R.; Rich, Thomas H.; Vickers-Rich, Patricia; Smith, Elizabeth T.; Helgen, Kristofer M. (2024-04-02). "A diverse assemblage of monotremes (Monotremata) from the Cenomanian Lightning Ridge fauna of New South Wales, Australia" . Alcheringa: An Australasian Journal of Palaeontology. 48 (2): 319–337. doi: 10.1080/03115518.2024.2348753 . ISSN   0311-5518.
  6. Hart et al. 2019.
  7. Frauenfelder et al. 2021.
  8. "Table 4.1," in Weishampel, Dodson & Osmólska 2004 , p. 74
  9. "Table 4.1," in Weishampel, Dodson & Osmólska 2004 , p. 78
  10. Bell, Burns & Smith 2018.
  11. Bell et al. 2016.
  12. Birch, Smith & Bell 2020.
  13. T-Bone Extension, Coocoran Opal Fields at Fossilworks.org
  14. Smith & Kear 2013.
  15. Smith, Elizabeth T. (September 2010). "Early Cretaceous chelids from Lightning Ridge, New South Wales". Alcheringa: An Australasian Journal of Palaeontology. 34 (3): 375–384. Bibcode:2010Alch...34..375S. doi:10.1080/03115518.2010.488117. S2CID   129726482.

Bibliography