Cutten, H.N.C. 1994 Geology of the middle reaches of the Mohaka River. Lower Hutt: Institute of Geological & Nuclear Sciences. Institute of Geological & Nuclear Sciences geological map 6 38 p. + 1 map
Abstract: The Mohaka map covers parts of the catchments of the Mohaka and Te Hoe rivers, in northwest Hawkes Bay, on the East Coast of the North Island. The tectonic setting is at the western flank of the forearc basin of the Hikurangi Subduction Margin. Neogene sediments of the forearc basin are flanked to the west by the Mohaka Fault. The uplifted axial ranges of Urewera Group greywacke (Late Jurassic) to the west of the fault have not been mapped. To the north are infaulted Upper Cretaceous to Lower Paleogene sediments. These include: Maungataniwha Sandstone Member (Mp-Mh) of the Tahora Formation (Tinui Group) comprising greywacke conglomerate and qandstone, both marine and non-marine (including terrestrial vertebrate fossils); Whangai Formation comprising mudstone of the Rakauroa Member (Mh-Dt) as well as a greensand and glauconitic mudstone unit; and the Waipawa Black Shale Formation (Dt). These are overlain by the Wanstead Formation (Dt-Ab) of the Mangatu Group comprising glauconitic sandstone and mudstone. The area has been prospected for oil, gold, copper, and hydroelectricity potential, but only road aggregate has been extracted so far. (auth)
