The Dunedin Volcano is an extensively eroded multi-vent

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more v ...

that was active between 16 and 10 million years ago. It originally extended from the modern city of

Dunedin Dunedin ( ; mi, Ōtepoti) is the second-largest city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from , the Scottish Gaelic name for Edinburgh, the capital of Scotland. Th ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Aramoana Aramoana is a small coastal settlement north of Dunedin on the South Island of New Zealand. The settlement's permanent population in the 2001 Census was 261. Supplementing this are seasonal visitors from the city who occupy cribs. The name '' ...

about 25 km away. Extensive erosion has occurred over the last 10 million years and

Otago Harbour Otago Harbour is the natural harbour of Dunedin, New Zealand, consisting of a long, much-indented stretch of generally navigable water separating the Otago Peninsula from the mainland. They join at its southwest end, from the harbour mouth. It ...

now fills the oldest parts of the volcano. The remnants of the volcano form the hills around

(including

Mount Cargill Mount Cargill, known in Māori as Kapukataumahaka,Place names'' on Kāti Huirapa Runaka ki Puketeraki website, viewed 2012-01-04 is a volcanic outcrop which dominates the skyline of northern Dunedin, New Zealand. The peak is named for Captain ...

, Flagstaff, Saddle Hill, Signal Hill, and

Otago Peninsula The Otago Peninsula ( mi, Muaūpoko) is a long, hilly indented finger of land that forms the easternmost part of Dunedin, New Zealand. Volcanic in origin, it forms one wall of the eroded valley that now forms Otago Harbour. The peninsula lies sou ...

). Volcanism began in a shallow marine environment. The volcano became larger with flows of basalt and minor

trachyte Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and al ...

creating the bulk of the volcano. The final phase of eruptions are preserved as phonolite domes around

. Traces of the old Dunedin Volcano are best seen in the Dunedin Botanic Garden's geology walk, the cliffs at

and the geomorphology of Mount Cargill which has preserved lava domes. Basaltic columns are also to be found as prominent features above Second Beach at St Clair and at

Blackhead A comedo is a clogged hair follicle (pore) in the skin. Keratin (skin debris) combines with oil to block the follicle. A comedo can be open (blackhead) or closed by skin (whitehead) and occur with or without acne. The word "comedo" comes from the ...

. This
Dunedin Volcano Animation
shows various locations around Dunedin with information on age of the rocks and general evolution of the Dunedin Volcano and more distant volcanism. Otago Harbour panorama

References

Geography of Dunedin Extinct volcanoes Shield volcanoes of New Zealand Miocene shield volcanoes Landforms of Otago Polygenetic shield volcanoes {{Volcano-stub

See also

References