Blackstone Formation, Australia

For other uses, see Blackstone Formation.

Blackstone Formation
Stratigraphic range: Carnian-Norian ~235–206  Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Ipswich Coal Measures
Sub-units	Denmark Hill Insect Bed, Striped Bacon Seam Member
Underlies	Unconformity with Raceview Formation and Aberdare Conglomerate
Overlies	Tivoli Formation
Thickness	200–240 m (660–790 ft)
Lithology
Primary	Shale
Other	Siltstone, coal, tuff
Location
Coordinates	27°36′S152°48′E / 27.6°S 152.8°E / -27.6; 152.8
Approximate paleocoordinates	58°36′S101°00′E / 58.6°S 101.0°E / -58.6; 101.0
Region	Ipswich
Country	Australia
Type section
Named for	Blackstone, Queensland
Blackstone Formation, Australia (Australia) Show map of Australia Blackstone Formation, Australia (Queensland) Show map of Queensland

The Blackstone Formation is a geologic formation of the Ipswich Coal Measures Group in southeastern Queensland, Australia, dating to the Carnian to Norian stages of the Late Triassic. The shales, siltstones, coal and tuffs were deposited in a lacustrine environment. The Blackstone Formation contains the Denmark Hill Insect Bed.

Fossil content

See also: Denmark Hill Insect Bed § Fossil content

Vertebrates

Lungfish

Dipnoans of the Blackstone Formation
Genus	Species	State	Abundance	Notes	Images
Ceratodus	C. robustus

Invertebrates

Insects of the Blackstone Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Mesochorista [1]	M. proavita	Ipswich			A Permochoionid
Mesodiphthera	M. grandis				Tettigarctid cicada
Tardilly	T. dunstani
	T. prosboloides
Phanerogramma	P. australis				Dermapterid earwig
Dinmopsylla	D. semota	Dinmore clay pit			Archipsyllid Permopsocid
Mesopsyche	M. triareolata	Dinmore clay pit			Mesopsychid mecopteran

Ichnofossils

In 1964, dinosaur footprints were discovered from the Rhondda colliery (underground coal mine) 230 metres below ground along the sandstone ceiling of the Striped Bacon coal seam. ^[2] These were initially described as Eubrontes , a type of predatory dinosaur (theropod) footprint. Later, these footprints were considered as evidence for the world's largest Triassic theropod, with legs towering over 2 metres tall. ^[3] A 3D evaluation of the fossil indicated the footprint length was much smaller than previously reported (34 cm rather than 46 cm long) and its shape was characteristic of the trace fossil genus (ichnogenus) Evazoum. ^[4] The existing hypothesis is that Evazoum were made by prosauropods, ancestral forms of long-necked sauropod dinosaurs. The bipedal dinosaur track-maker may have resembled the dinosaur Plateosaurus , and this fossil is the only evidence of this group of dinosaurs in Australia. The next evidence for sauropodomorphs in Australia comes over 50 million years later in the Jurassic.

See also

• List of fossil sites

References

1. E.F. Riek (1955). "A Re-examination of the Mecopteroid and Orthopteroid Fossils (Insecta) from the Triassic Beds at Denmark Hill, Queensland, with Descriptions of Further Specimens" (PDF). Australian Journal of Zoology. 4: 98–110. doi:10.1071/ZO9560098 . Retrieved 11 August 2011.
2. Staines, H. R. E. (1964). "Recent discovery of Triassic dinosaur footprints in Queensland". Australian Journal of Science. 27: 55.
3. Thulborn, T. (11 July 2003). "Comment on "Ascent of Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary"" . Science. 301 (5630): 169. doi:10.1126/science.1082048. ISSN   0036-8075. PMID   12855792. S2CID   13247451.
4. Romilio, Anthony; Klein, Hendrik; Jannel, Andréas; Salisbury, Steven W. (16 October 2021). "Saurischian dinosaur tracks from the Upper Triassic of southern Queensland: possible evidence for Australia's earliest sauropodomorph trackmaker". Historical Biology. 34 (9): 1834–1843. doi:10.1080/08912963.2021.1984447. ISSN   0891-2963. S2CID   239170287.

Bibliography

• Staines, H. R. E.; Woods, J. T. (1964), "Recent discovery of Triassic dinosaur footprints in Queensland", The Australian Journal of Science , 27: 1–55