Ōmana Regional Park

Ōmana Regional Park is situated south-east of Auckland and just west of Maraetai, in the Franklin area of the Auckland Region of New Zealand's North Island. It is owned and managed by Auckland Council.

Geography

The park is located on a gently contoured knoll, which rises 40 meters above sea level. From the highest point looking inland, visitors can see from Maraetai to the Beachlands settlements. Looking seaward, there are views of the Hauraki Gulf.http://www.nzarchaeology.org/northauckcoro.htm retrieved 2008

The eastern boundary is the Whitford-Maraetai road which is separated from view by a strip of mature native bush. There are 40.81 hectares of park of which about 20 hectares are used to graze sheep and the rest is used for recreational activities.

Birds

At least twenty-six different types of bird are found in the park. natives include: pied stilt, pukeko (''Porphyrio melanotus''),
kereru, tui which appears almost black except for a white tuft under its chin, fantail, grey warbler, red-billed gull, southern black-backed gull (see kelp gull), South Island pied oystercatcher and the closely related variable oystercatcher (''Haematopus unicolor''), pied shag, kingfisher, and white-faced heron.Regional Parks Management Plan: Volume 2 Resource Inventory. Page 49 The white-fronted tern can be found resting on the greywacke outcrops which become visible at low tide.

Geology

The beach and extensive rock platform, form the northern boundary of the park. The whole of Omana Regional Park is underlain at a depth of 30 – 100m by ancient greywacke (a harder basement sedimentary rock). The greywacke belongs to the Waiheke group. The softer more recent sandstone is of the Waitamata group.

The layered sandstones and siltstones (mudstones) are seen in the cliff faces and also form the shore platform around the north
and west sides of the park. These softer, generally yellow-brown rocks are approximately 19-20 million years old and are made up of the Waitamata formation (East Coast Bays facies) of early Miocene (Late Otaian) age.http://www.geotours.co.nz/geo-noteomana.html Geological notes on Omana. Retrieved March 2008 Distortion and faulted dipping, of this once soft strata, can be seen both in the cliffs and in the small ridges of the rock platform extending out from the beach at low tide.

What makes an interesting discovery is that protruding through the softer yellow-brown sedimentary sandstone and mudstone layers, there are ancient (200-million-year-old) tips of greywacke sea stacks from the Jurassic age. They are older and harder (cut or formed from the original 200-million-year-old greywacke about 25 million years ago). They are about 1–2 meters high and are found in the shore platform, about 200 metres east of the park at Omana Beach.

Holocene sands (less than 7000 years old) form the flat area behind Omana Beach and at Te Puru Creek.

Simplified geological overview

200 - 150 million years ago sand eroded from the super-continent Gondwana into a deep trough in the sea floor. These deposits were kilometers thick and compressed, folded and heated became hard greywacke.

150 - 120 million years ago The hard greywacke was uplifted and became the first mountainous backbone of New Zealand. 120 - 70 million years ago the mountain ranges were eroded to a great degree. 35 – 15 million years ago the sea completely covered much of New Zealand. During this long quiet period, sediments were deposited over the old basement rock and gradually metamorphosed into sandstones. 15 – 5 million years ago The greywackes were again uplifted (Late Miocene). This second set of earth movements, known as the Kaikoura Orogeny, elevated large fault-bounded blocks to form the horsts (upfaulted blocks of land) of the Hunua and Coromandel Ranges, and threw down the grabens (down-faulted blocks) of the Firth of Thames and Hauraki Gulf which Omana now overlooks.

Vegetation

Apart from the pohutukawa and grass areas, there is a southern patch of mature tanekaha and a northern patch of puriri (ripe red berries) and taraire. Other large trees include rewarewa, mapou, kowhai, totara, tree ferns, cabbage trees, and kahikatea. Kanuka can be found on the slopes of the Te Puru creek (the estuarine mangrove salt marsh).

Intertidal ecology

The intertidal ecology is mainly composed of three areas:

*Rocky shore platform with small pools at low tide on north and west of the park are occupied by small barnacles, rock oysters, Neptune's necklace (a sea weed) and tube worms.
*Sand and mudflats surrounding the shore platform contain cockles, pipi (''Paphies australis''), crabs and Polychaete worms. Because of the cockle bed out in the sea, the cockle shells wash up high on the beach during storms. The sand can be found underneath.
*Mangroves with mud snails (''Amphibola crenata''), small mussels and barnacles.

History

Ngai Tai along with members of other Hauraki tribes, lived in the Omana park area for many generations.
On the perimeter track, visitors will find a grassed area, overlooking the sea, which was the original site of a Ngai Tai pā. (see Maori Pa). This grassed area has a deep ditch whose internal bank would have once been much higher and topped with a strong palisade of posts. O-Manawatere is a relatively small pā.

The park's name ‘Omana’ is short for O-Manawatere ("the dwelling place of Manawatere"). According to legend, "This man Manawatere came from Hawaiki, he did not come in a canoe ( waka), he glided over the ripples of the waves". The ARC information board beside the pa says he rode on the back of a taniwha.

The park was part of William Fairburn's Maraetai Mission Station which included a small school for Maori from 1837 - 42. Omana was part of the mission farm, developed from 1837. The forest covering the park and surrounding area was felled for timber by European settlers who cleared the land for farming during the mid-1840s. Kauri felled in the Maraetai hills behind Omana was hauled by bullock teams down to the sea and then floated to mills in Auckland. The Omana park area was also dug for kauri gum and even prospected for gold and silver. In 1852 following the discovery of gold in Coromandel many searched the hills digging shafts wherever quartz veins could be located.http://www.pohutukawacoast.co.nz/w/Local-History-109.html retrieved 2008

Gallery

Image:Puriri tree.jpg, Puriri (Vitex lucens) at Omana with red berries in summer.
Image:Omana Neptunes necklace.jpg, Neptune's necklace, Omana.
Image:Omana dry pasture.jpg, Dry grass of February. One sheep on the horizon, Omana.
Image:Omana kauri.jpg, Young kauri on the perimeter walk.
Image:Omana oysters.jpg, Oyster shells on Omana beach.
Image:Omana Raupo.jpg, Raupo at Omana.
Image:Omana kumara pits.jpg, Kumara pit on the pa site.
Image:Omana goats cabbage.jpg, Goats and cabbage trees in the ditch beside the pa site.
Image:Omana black goat.jpg, Goat with the pa ring ditch in the background.
Image:Omana birds.jpg, Two variable oystercatchers ''Haematopus unicolor''. Omana.
Image:mud snail.jpg, Mud snail near mangroves. ''Amphibola crenata'' (titiko).
Image:Greywacke_terns.jpg, White-fronted terns on ancient Greywacke sea stack.

References

External links

Auckland Regional Parks
- Omana
Gives descriptions of geology of Duder park, Waiheke and Hunua etc

{{Protected areas of New Zealand

Franklin Local Board Area
Parks in the Auckland Region
Regional parks of New Zealand
Tourist attractions in the Auckland Region