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South Island Surface Volcanism
The volcanic activity in the South Island of New Zealand terminated 5 million years ago as the more northern parts of the North Island became extremely volcanically active. The South Islands surface geology reflects the uplift of the Pacific plate as it collides with the Indo-Australian plate along the Alpine Fault over the last 12 million years and the termination of subduction, about 100 to 105 million years ago. There is a very small chance of reactivation of volcanism in the Dunedin Volcano. This chance is made slightly higher by the observation that Southland's Solander Islands / Hautere just off the coast of the South Island were active as recently as 50,000 years old, and on a larger scale 150,000 years old. Geology The South Island portion of Zealandia is divided from the point of view of basement rocks into an older "Western Province", consisting mainly of greywacke, granite and gneiss, down the West Coast and in a swing to Steward Island and an "Eastern Province" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zealandia
Zealandia (pronounced ), also known as (Māori language, Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged continent, submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83–79 million years ago. It has been described variously as a submerged continent, continental fragment, and microcontinent. The name and concept for Zealandia was proposed by Bruce P. Luyendyk, Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is over a billion years old, about twice as old as geologists previously thought. By approximately 23 million years ago, the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia. Mapping of Zealandia concluded in 2023. With a total area of approximately , Zealandia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banks Peninsula
Banks Peninsula () is a rocky peninsula on the east coast of the South Island of New Zealand that was formed by two now-extinct volcanoes. It has an area of approximately . It includes two large deep-water harbours — Lyttelton Harbour and Akaroa Harbour — and many smaller bays and coves. The South Island's largest city, Christchurch, is immediately north of the peninsula which, is administered by Christchurch City Council. The main settlements are Lyttelton and Akaroa. The peninsula's economy is based on fisheries, farming and tourism. Māori were the first people to visit, and settle, the peninsula. The sparse population was reduced further following massacres by raiding parties of North Island Māori in 1830 and 1832. In 1770, explorer James Cook became the first European to sight the peninsula, which he mistook for an island, naming it after his ship's botanist Joseph Banks. From the 1830s, European whalers set up shore-based stations in some of the bays and harbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otago
Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government region. Its population was The name "Otago" is the local Māori language#South Island dialects, southern Māori dialect pronunciation of "Otakou, Ōtākou", the name of the Māori village near the entrance to Otago Harbour. The exact meaning of the term is disputed, with common translations being "isolated village" and "place of red earth", the latter referring to the reddish-ochre clay that is common in the area around Dunedin. "Otago" is also the old name of the European settlement on the harbour, established by the Weller Brothers in 1831, which lies close to Otakou. The upper harbour later became the focus of the Otago Association, an offshoot of the Free Church of Scotland (1843–1900), Free Church of Scotland, notable for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shag Point
Shag Point / Matakaea is a headland and township in East Otago, New Zealand. Both the point and the nearby Shag River take their English name from a seabird, the pied shag. The township extends along a single road, which leaves State Highway 1 nine kilometres to the northeast of Palmerston, at the southern end of a long open bay known as Katiki Beach. The road links the highway with the point itself, three kilometres southeast of the junction. The point is a hilly promontory between Katiki Beach and the mouth of the Shag River. The headland is within the Matakaea Scenic Reserve, which is known for its population of New Zealand fur seals. A historic Māori site, the Matakaea/Shag Point Occupation Site, is located close to the headland. It is listed as a Category II site by Heritage New Zealand. Geologically, the area is an exemplar of the Katiki Formation, and the site of the discovery of the plesiosaur '' Kaiwhekea katiki''. It is also the location of the oldest char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869–1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of extremely vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker vesicle walls, and being dark colored and denser.Jackson, J.A., J. Mehl, and K. Neuendorf (2005) ''Glossary of Geology'' American Geological Institute, Alexandria, Virginia. 800 pp. McPhie, J., M. Doyle, and R. Allen (1993) ''Volcanic Textures A guide to the interpretation of textures in volcanic rocks'' Centre for Ore Deposit and Exploration Studies, University of Tasmania, Hobart, Tasmania..198 pp. Pumice is created when super-heated, highly pressurized rock is rapidly ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naseby, New Zealand
Naseby is a small town, formerly a borough, in the Maniototo area of Central Otago, New Zealand. It is named after a village in Northamptonshire, England, which was the site of a major battle during the English Civil War. Previous names of the township were Parker's, Hogburn and Mt Ida. The town catch phrase is "2000 feet above worry level" indicating its altitude. Naseby is 395 km (5 hours drive) from Christchurch and 143 km (1 hour 45 minutes drive) from Dunedin. History An important township during the gold rush of the 1860s, Gold was discovered in the Hogburn in 1863. Much of the town has been preserved from this time and has something of the air of a working museum. At its peak, the population of the town was around 4,000 miners. Eighteen stores, 14 hotels, two butchers and a hospital had also been built to service the miners. In 1898, a railway line was constructed 12 km away in Ranfurly and as a result services gradually moved away from Naseby to Ranf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of New Zealand
The geology of New Zealand is noted for its volcanic activity, earthquakes and Geothermal areas in New Zealand, geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand is part of Zealandia, a microcontinent nearly half the size of Australia that broke away from the Gondwanan supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique fossil record and modern Environment of New Zealand, ecology. New Zealand's geology can be simplified into three phases. First the basement rocks of New Zealand formed. These rocks were once part of the super-continent of Gondwana, along with South America, Africa, Madagascar, India, Antarctica and Australia. The rocks that now form the mostly submerged continent of Zealandia were then nestled between Eastern Australia and Western Antarctica. Secondly New Zealand drifted away from Gondwana and many sedimentary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as mica, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steward Island
Steward Island (; also ''Stewart Ø'' in some sources)''Prostar Sailing Directions 2005 Greenland and Iceland Enroute'', p. 111 is an uninhabited island in King Christian IX Land, at the eastern end of Greenland. Administratively it is part of the Sermersooq municipality. The island is mountainous and clearly visible from a distance. According to mariners' reports the island is a good landmark for vessels approaching Greenland from the east. Geography Steward is a coastal island of the Blosseville Coast located in a bay off the Savoia Peninsula. It lies 39 km to the SW of Cape Brewster and 7.5 km to the northeast of the small Manby Peninsula. To the west there is a wide glacier discharging in the bay and the island's western end is attached to the terminus of the glacier, so that it almost forms a peninsula with the mainland. The island is long with a maximum width of . The small Dunholm islets ''(Dunholm Øer)'' lie 4 km to the east and the high Pyramiden, an ultra-promine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
