Takatika Grit Explained

Takatika Grit
Type:Formation
Period:Paleocene
Prilithology:Grit, sandstone
Region: (Chatham Island)
Unitof:Tioriori Group
Subunits:,,,
Underlies:Tutuiri Greensand
Overlies:Chatham Schist
Thickness:5.7 metres exposed

The Takatika Grit is a geologic formation in Chatham Islands, New Zealand. It preserves fossils dating back to the Paleocene period, although it also preserves disturbed and re-worked Maastrichtian and Campanian microfossils and tetrapod fossils. A 2017 study found that it dated to late Early to Mid Paleocene on the basis of dinoflagellates. It has been subdivided into two informal units, a lower phosphatic unit containing bones and nodular phosphatic layers, and an upper unit with abundant sponge remains and siliceous microfossils.[1]

Description

The two informal units are further subdivided into two units each, the lower is divided into the lower which consists of "poorly sorted, phosphatized grit with abundant phosphorite nodules and bones" and the upper which consists of "nodular bedded sandstone and grit". The upper biosiliceous unit is divided into the lower, which is heavily bioturbated, and the upper "characterized by parallel laminations and sinusoidal ripples".

Paleofauna

Paleofauna of the Takatika Grit
GenusSpeciesLocationStratigraphic positionAbundanceNotesImages -->-Astrophorida indet.indeterminateTiorioriOnly fragmentary spicules are known
Auloplax? (Dactylocalycidae indet.?)A? sp.TiorioriHexactinellid sponge
Bacillariophyceae indet.IndeterminateTiorioriDiatoms from the Takatika Grit date back to the Danian and Campanian
Chlamydoselachus[2] IndeterminateTioriori
Dinoflagellata indet.[3] IndeterminateTiorioriDinoflagellates from the Takatika Grit date back to the Danian and Campanian
EdaphodonE. kawaiTioriori
Elasmosauridae indet.[4] indeterminateTioriorilower (?) Takatika GritAlmost certainly reworked from older sediments.
EotretochoneE. australisTiorioriHexactinellid sponge
Euretidae indet.IndeterminateTioriori
Kupoupou[5] K. stilwelliTiorioriPenguin
Gastropoda indet.[6] IndeterminateTioriori
Lithistida indet.IndeterminateTiorioriKnown from scarce weathered fragments
Lycopodiopsida indet.IndeterminateTioriori
Mosasauridae indet.IndeterminateTioriorilower (?) Takatika GritAlmost certainly reworked from older sediments.
Radiolaria indet.IndeterminateTiorioriRadiolarians from the Takatika Grit date back to the Danian and Campanian
ParareteP. sp.TiorioriHexactinellid sponge
Theropoda indet.[7] IndeterminateTioriorilower (?) Takatika GritVertebral centrum, tibia head, proximal pedal phalanx, manual ungual, proximal manual phalanxInitially suggested to represent evidence of Palaeogene dinosaurs.[8] [9] [10] Almost certainly reworked from older sediments.
Tretodictyiidae indet.IndeterminateTioriori

See also

Notes and References

  1. Hollis. Christopher J.. Stickley. Catherine E.. Bijl. Peter K.. Schiøler. Poul. Clowes. Christopher D.. Li. Xun. Campbell. Hamish. 2017-07-03. The age of the Takatika Grit, Chatham Islands, New Zealand. Alcheringa: An Australasian Journal of Palaeontology. en. 41. 3. 383–396. 10.1080/03115518.2017.1296189. 133527355 . 0311-5518.
  2. Consoli. Christopher P.. 2008-06-12. http://www.tandfonline.com/doi/abs/10.1671/0272-4634(2008)28[285:ARDEPC2.0.CO;2 A rare Danian (early Paleocene) Chlamydoselachus (Chondrichthyes: Elasmobranchii) from the Takatika Grit, Chatham Islands, New Zealand]. Journal of Vertebrate Paleontology. en. 28. 2. 285–290. 10.1671/0272-4634(2008)28[285:ARDEPC]2.0.CO;2. 130714866 . 0272-4634.
  3. Hollis, C.J, Stickley, C.E., Bijl, P.K., Schiøler, P., Clowes, C.D., Li, X, Campbell, H. March 2017. The age of the Takatika Grit, Chatham Islands, New Zealand. Alcheringa 41, xxx–xxx. ISSN 0311-5518.
  4. Consoli. Christopher P.. Stilwell. Jeffrey D.. August 2009. Late Cretaceous marine reptiles (Elasmosauridae and Mosasauridae) of the Chatham Islands, New Zealand. Cretaceous Research. en. 30. 4. 991–999. 10.1016/j.cretres.2009.02.009.
  5. Jacob C. Blokland, Catherine M. Reid, Trevor H. Worthy, Alan J.D. Tennyson, Julia A. Clarke, and R. Paul Scofield. 2019. Chatham Island Paleocene Fossils provide insight into the Palaeobiology, Evolution, and Diversity of early Penguins (Aves, Sphenisciformes). Palaeontologia Electronica. 22.3.78; 1-92.
  6. Stilwell. Jeffrey D.. March 2007. First record of Late Cretaceous Gastropoda (Mollusca) from the Takatika Grit, Chatham Islands, Southwest Pacific. New Zealand Journal of Geology and Geophysics. en. 50. 1. 21–25. 10.1080/00288300709509816. 0028-8306. free.
  7. J.D. . Stilwell . C.P. . Consoli . R. . Sutherland . S. . Salisbury . T.H. . Rich . P.A. . Vickers-Rich . P.J. . Currie . G.J. . Wilson . Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K–T boundary Takatika Grit . 2006 . Palaeogeography, Palaeoclimatology, Palaeoecology . 230 . 4 . 243–250 . 10.1016/j.palaeo.2005.07.017 .
  8. Fordyce, R. E. 2006. New light on New Zealand Mesozoic reptiles. Geological Society of New Zealand newsletter 140: 6-15.
  9. Haw, D. 2002. The discovery of fossils in Mangahouanga Stream. Geological Society of New Zealand newsletter 129: 13-14.
  10. Fordyce, R. E. 2003. Fossils and the history of life. Pp 35-64 in Darby, J. T., Fordyce, R. E., Mark, A. F., Probert, P. K., & Townsend, C. R. (eds), The natural history of southern New Zealand. University of Otago Press, Dunedin. 387 p.