Mouth of Awakino River (Miocene of New Zealand)

Where: New Zealand (38.7° S, 174.6° E: paleocoordinates 43.4° S, 176.2° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Mohakatino Formation, Tortonian (11.6 - 7.2 Ma)

• Basal Mohakatino Formation. Basal tuff bed of Mohakatino Formation. Maier et al. (2016) conducted detailed biostratigraphic and geochronologic dating. A sample 15 m above the base contains a rich planktic foraminiferal fauna with common Hirsutella panda in conjunction with a sinistrally coiled population of Globoconella miotumida and rare specimens of Paragloborotalia mayeri s.l. This combination of taxa indicates this sample is correlated with the top of the upper Hr. panda acme zone, above the stratigraphic top of the Mapiri Coiling Zone, and that it has a correlated age of 10.65 Ma. Dextrally coiled specimens of Neogloboquadrina incompta at 74 m, the only specimens of Nq. incompta that have been identified in the lower part of the coastal section, are correlated with the upper part of the Glomar Coiling Zone (GCZ), above the stratigraphic level of the lowest common occurrence of species associated with the Nq. pachyderma-incompta group. This interval has a correlated age of 10.36–10.39 Ma. An ash bed 80 m above the base of the formation yielded a U-Pb zircon age of 10.63 ± 0.65 Ma.

• group of beds-level stratigraphic resolution

Environment/lithology: submarine fan; lithified siliciclastic sediments

• According to Shumaker et al. (2018): The Mohakatino Formation has been interpreted previously as a deep-water volcanogenic apron or fan delta (Nodder et al., 1990a). However, submarine volcanic apron facies documented elsewhere are characterized by common dyke intrusions and lava flows that are interbedded or in close lateral association with re-sedimented volcanogenic deposits (e.g. Gamberi, 2001; Allen et al., 2007; Corral et al., 2013). Primary volcanic deposits and intrusions are absent from the Mohakatino Formation in the study area. The findings of the current study instead suggest a submarine lobe environment, implying greater transport distances for the volcanogenic sediments than in an apron setting. Deposited in middle to lower bathyal water depths (Nodder et al., 1990a).

Size class: macrofossils

Reposited in the IGNS

Primary reference: A. G. Beu. 1973. Nautiloids of the genus Aturia from the uppermost Miocene of Australia and New Zealand. Science Reports of the Tohoku University. Second Series, Geology. Special Volume (Hatai Memorial Volume) 6:297-308 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 180128: authorized by Matthew Clapham, entered by Matthew Clapham on 08.07.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Cephalopoda
 Nautilida - Aturiidae
Aturia coxi
Aturia coxi Miller 1947 nautiloid