Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Sedimentology and evolution of Ohiwa Harbour, a barrier-impounded estuarine lagoon in Bay of Plenty Journal Paper

Author
Richmond, B.M.; Nelson, C.S.; Healy, T.R.
Year
1984
Journal / Source
New Zealand Journal of Marine and Freshwater Research
Volume
18
Pages
461-478
Keywords
Quatemary, Pleistocene, Holocene, Kaihu Group, North Kaipara Barrier, Hautawan, Okehuan, palynology, terraces, stratigraphy, sea levels, South Head Formation, Shelly Beach Formation, new stratigraphie names, Dargaville Formation, Rototuna Formation, Pareotaunga Formation
Summary
North Kaipara Barrier is formed by sediments, mainly estuarine and dune sands of the Kaihu Group, deposited in a major cyc1e of transgression (subsidence) and regression (uplift) during the Quatemary. Hautawan, Okehuan and younger lignites along with terrace surfaces at 105 m, 67 m, 40 m, 24 m, 8 m and 4-2 m a.s.l., which can be correlated with dated surfaces elsewhere in the North Island, provide chronologie contro!. Five units, the Hautawan DargaviIle Formation, Nukumaruan-Castlec1iffian Rototuna Formation, Castlec1iffian-Hawera Pareotaunga Formation, Hawera South Head Formation, and the Hawera Shelly Beach Formation, are present. The barrier has changed littie since the end ofOkehuan time when the major existing valleys were cut in Rototuna sediments. Upper Pleistocene terrace surfaces are locally preserved within these valleys. Undifferentiated Hawera and Holocene deposits are also present on the barrier.