The Tangahoe Formation is a geologic formation in the southwestern North Island of New Zealand.
The formation occurs in the Taranaki and Manawatū-Whanganui Regions, spreading in an east–west band for from the volcanic deposits of Mount Taranaki in the west to the Ruahine Ranges in the east, in a band with an average width of around .Kamp, P. J. J., et al. (2023) "Geology map of western North Island, showing the main stratigraphic units in the Taranaki, King Country and Wanganui basins," www.researchgate.net. Accessed 9 February 2023. It becomes exposed at its western end close to the Tasman Sea coast near Hāwera in a series of cliff faces.Naish, T. R., et al. (2005) "An integrated sequence stratigraphic, palaeoenvironmental, and chronostratigraphic analysis of the Tangahoe Formation, southern Taranaki coast, with implications for mid-Pliocene (c. 3.4–3.0 Ma) glacio-eustatic sea-level changes," Journal of the Royal Society of New Zealand, 35(1&2), 151-196. Accessed 9 February 2023. The formation takes its name from the Tangahoe River, which is located close to the exposed cliffs.
The formation is sedimentary, composed largely of muddy sandstones, and was formed beneath sea level in the Waipipian stage of the mid-Pliocene some 3.4 to 3.0 million years ago.
Fossil content
The formation is an important fossil site. Many marine fossils have been recovered from its mudstones, including the megalodon shark, giant petrel Macronectes tinae, penguin Eudyptes atatu, monk seal Eomonachus belegaerensis, and cetaceans.Lambert, R., "Taranaki region - Geology and climate," Te Ara - the Encyclopedia of New Zealand Accessed 9 February 2023.
Mammals Mammals reported from the Tangahoe Formation Genus Species Presence Material Notes ImagesDelphinidae indet.IndeterminateWaihi BeachMandible.A dolphin, probably from a species of Delphinus or Stenella.EomonachusE. belegaerensisNorthwest of Waihi Stream on Ohawe and Waihi Beaches.Skull elements.A monk seal.
Birds Birds reported from the Tangahoe Formation Genus Species Presence Material Notes ImagesAldiomedesA. angustirostrisOhawe Beach.Skull.An albatross.ArdennaA. buchananbrowniOhawe & Waihi beaches.2 partial skeletons.A shearwater.A. davealleniOhawe Beach.Partial skeleton.A shearwater.EudyptesE. atatuNo exact locality record.Multiple partial skeletons.A penguin.EudyptulaE. wilsonaeNo exact locality record.Skulls.A penguin.MacronectesM. tinaeHawera.Skull & humerus.A petrel.PelagornithidaeUndescribedWaihi Beach.Partial humerus & radius.An unnamed species of pseudotooth bird.ProcellariaP. altirostrisOhawe Beach.Partial skeleton.A petrel.TereingaornisT. moisleyiWaihi Beach.Left humerus & coracoid.A penguin, now deemed a nomen dubium.
Fish Fish reported from the Tangahoe Formation Genus Species Presence Material Notes ImagesCarcharodonC. megalodonHawera.Vertebrae.Species now moved to Otodus.IkamauiusI. ensiferWaihi Beach.Rostral denticle.A sawshark.OtodusO. megalodonHawera.Vertebrae.A megatooth shark, originally reported as Carcharodon megalodon.PristiophorusP. lanceolatusNorthwest of the Tangahoe River mouth.Rostral denticle.Species now deemed a nomen dubium, specimen reassigned as P. sp.P. sp.Northwest of the Tangahoe River mouth.Rostral denticle.A sawshark, originally reported as P. lanceolatus.cf. Tetrosomuscf. T. sp.Waihi BeachA near-complete articulated specimen.A boxfish.
Invertebrates Invertebrates reported from the Tangahoe Formation Genus Species Presence Material Notes ImagesPalaegaP. kakatahiBetween Raukawa Falls & Kakatahi.A single specimen.A cirolanid isopod.
References