Banks Peninsula, Christchurch City, Canterbury Region, New Zealandi

Regional Level Types
Banks Peninsula	Peninsula
Christchurch City	City
Canterbury Region	Region
New Zealand	Country

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The area comprises two volcanic cones that have eroded into several deep valleys and two harbours.

The Banks Peninsula covers 1200 square kilometres, on the east coast of the South Island, The central town of Akaroa is 93 kilometres from Christchurch. It is a very scenic area, evident as the main road comes down into the Akaroa Harbour. Akaroa is a line of Victorian and French historic wooden buildings along the waterfront, the most important a rock shop, with waterside park, and jetty. Main activities involve wildlife viewing, including marine mammals, penguins, and sea birds.

A look at the map and it will become quickly evident that the Banks Peninsula is of volcanic origin. The following is a brief summary based on (Dorsey, 1988). Initially the Lyttleton volcano to the north erupted (11Ma), followed by minor eruptions of the Church, Mount Herbert, and Diamond Harbour groups, representing a gradual migration of volcanic activity from Lyttelton to Akaroa. The above events formed what is now showing as the northern third of the peninsula.

The other or south-eastern two thirds is the result of the Akaroa volcano
(9.0 Ma), its main vent near the Onawe Peninsula, seen when driving into Akaroa, at the head of Akaroa Harbour. The volcano's history is divided into an Early Phase 1, 2, 3, and Main Phase, followed by erosion and rising sea levels forming the Akaroa Harbour, and eventually transformation of the island, to part of the east coast as Southern Alps shingle was deposited along the shoreline.

All the rocks along the Inner harbour, except for some minor plutonic rocks
on the Onawe Peninsula, are from the early phases. This shows more trachytic, pyroclastic, epiclastic material, weathered basalt flows, and dyke formations than the Main Phase. Trachytic (and minor basaltic) dykes are abundant (643 and counting) around the Akaroa Harbour, showing as irregular, concentric and radial trending at Onawe Peninsula, concentric and radial around the Akaroa Harbour, and decreasing significantly away from the harbour showing as radial only. The Onawe Peninsula shows a scoria cone at its isthmus.

The Main Phase shows as grey fine grained aphyric to strongly porphyritic basalt, and hawaiite lava flows, dipping away from the harbour, a few hundred metres long, following the valleys of the early volcano. Dorsey uses the locations of Saddle Hill, High Bare Peak, and Lighthouse Road as examples. Parasitic vents occurred away from the main vent, with Dorsey using Scenery Cove as an example. There are also five large trachyte domes,
as intrusive bodies fed from trachyte dykes. These are Panama Rock, View Hill, Devils Gap, Pulpit Rock, and Ellagowan.

The eruptions were predominantly basaltic, with associated andesite and trachytes, with minor rhyolite. The volcanic activity occurred in the Late Miocene and possibly extended into the Early Pliocene. There are four volcanic groups, all of which are within the Māui Supergroup (Mortimer et al, 2014).

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.

Mineral List

Mineral list contains entries from the region specified including sub-localities

28 valid minerals.

Rock Types Recorded

Rock list contains entries from the region specified including sub-localities