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Dun Mountain–Maitai Terrane
The Dun Mountain–Maitai terrane comprises the Dun Mountain ophiolite belt (also called the mineral belt), Maitai group, and Patuki mélange. The Dun Mountain Ophiolite is an ophiolite of Permian age located in New Zealand's South Island. Prehistorically this ophiolite was quarried by Māori for both metasomatized argillite and pounamu (jade) which was used in the production of tools and jewellery. In the late 1800s, the Dun Mountain ophiolite belt was surveyed for its economic potential. During this time the rock types dunite and rodingite (after Dun Mountain and the Roding River) were first named. Discovery of economic deposits of chromite near Nelson lead to the building of New Zealand’s first railway, however, extraction only occurred between 1862 and 1866. In the 20th century, serpentinite was mined for fertiliser and the ophiolite remains one of New Zealand's main sources of pounamu (jade), but all other mineral exploration has failed to find economic deposits. Descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dun Mountain
Dun Mountain is a mountain in the Richmond Range near the city of Nelson in the Tasman District of New Zealand's South Island. It is located between the catchments of the Pelorus, Maitai and Roding Rivers. The mountain is named for its brown (Dun) colour. The colour is caused by the ultramafic rock which forms the mountain. Ultramafic Rock weathers to this colour and plant growth is also stunted due to the soils high heavy metal content. The ultramafic rock formed in the Earth's mantle in the Permian and is now part of the Dun Mountain Ophiolite Belt. In 1859 the rock type dunite was first identified on the mountain and named after it. Between 1850 and 1865 small deposits of chromite and copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ... were mined on the mountain leadin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodingite
Rodingite is a metasomatic rock composed of grossular- andradite garnet, calcic pyroxene, vesuvianite, epidote and scapolite. Rodingites are common where mafic rocks are in proximity to serpentinized ultramafic rocks. The mafic rocks are altered by high pH, Ca2+ and OH− fluids, which are a byproduct of the serpentinization process, and become rodingites. The mineral content of rodingites is highly variable, their high calcium, low silicon and environment of formation being their defining characteristic. Rodingites are common in ophiolites, serpentinite mélanges, ocean floor peridotites and eclogite massifs. Rodingite was first named from outcrops of the Dun Mountain Ophiolite Belt in the Roding River, Nelson, New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla .... An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunite
Dunite (), also known as olivinite (not to be confused with the mineral olivenite), is an intrusive igneous rock of ultramafic composition and with phaneritic (coarse-grained) texture. The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite, magnetite, and pyrope. Dunite is the olivine-rich endmember of the peridotite group of mantle-derived rocks. Dunite and other peridotite rocks are considered the major constituents of the Earth's mantle above a depth of about . Dunite is rarely found within continental rocks, but where it is found, it typically occurs at the base of ophiolite sequences where slabs of mantle rock from a subduction zone have been thrust onto continental crust by obduction during continental or island arc collisions (orogeny). It is also found in alpine peridotite massifs that represent slivers of sub-continental mantle exposed during collisional orogeny. Dunite typically undergoes retrogra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jade
Jade is an umbrella term for two different types of decorative rocks used for jewelry or Ornament (art), ornaments. Jade is often referred to by either of two different silicate mineral names: nephrite (a silicate of calcium and magnesium in the amphibole group of minerals), or jadeite (a silicate of sodium and aluminum in the pyroxene group of minerals). Nephrite is typically green, although may be yellow, white or black. Jadeite varies from white or near-colorless, through various shades of green (including an emerald green, termed 'imperial'), to Lavender (color), lavender, yellow, orange, brown and black. Rarely it may be blue. Both of these names refer to their use as gemstones, and each has a mineralogically more specific name. Both the amphibole jade (nephrite) and pyroxene jade are mineral aggregates (rocks) rather than mineral species. Nephrite was deprecated by the International Mineralogical Association as a mineral species name in 1978 (replaced by tremolite). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pounamu
Pounamu is a term for several types of hard and durable stone found in the South Island of New Zealand. They are highly valued in New Zealand, and carvings made from pounamu play an important role in Māori culture. Name The Māori word is derived from ''namu'', an archaic word that describes blue-green (or 'grue') cognate with Tahitian ''ninamu''. , also used in New Zealand English, in itself refers to two main types of green stone valued for carving: nephrite jade, classified by Māori as , , , and other names depending on colour; and translucent bowenite, a type of serpentine, known as . The collective term pounamu is preferred, as the other names in common use are misleading, such as New Zealand jade (not all pounamu is jade) and greenstone (a generic term used for unrelated stone from many countries). Pounamu is only found in New Zealand, whereas much of the carved "greenstone" sold in souvenir shops is jade sourced overseas. The Māori classification of pouna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argillite
Argillite () is a fine-grained sedimentary rock composed predominantly of Friability, indurated clay particles. Argillaceous rocks are basically lithified muds and Pelagic sediment, oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the Fissility (geology), fissile layering typical of shale is developed. Another name for poorly lithified argillites is ''mudstone''. These rocks, although variable in composition, are typically high in aluminium and silica with variable alkali and alkaline earth cations. The term pelite, ''pelitic'' or ''pelite'' is often applied to these sediments and rocks. Metamorphism of argillites produces slate, phyllite, and pelitic schist. Belt Supergroup The Belt Supergroup, an assemblage of rocks of late Precambrian (Mesoproterozoic) age, includes thick sequences of argillite, as well as other metamorphosed or semi-metamorphosed mudstones.Schieber, J. 1990. Significance of styles of epicontinental shale sedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Māori People
Māori () are the Indigenous peoples of Oceania, indigenous Polynesians, Polynesian people of mainland New Zealand. Māori originated with settlers from East Polynesia, who arrived in New Zealand in several waves of Māori migration canoes, canoe voyages between roughly 1320 and 1350. Over several centuries in isolation, these settlers developed Māori culture, a distinct culture, whose language, mythology, crafts, and performing arts evolved independently from those of other eastern Polynesian cultures. Some early Māori moved to the Chatham Islands, where their descendants became New Zealand's other indigenous Polynesian ethnic group, the Moriori. Early contact between Māori and Europeans, starting in the 18th century, ranged from beneficial trade to lethal violence; Māori actively adopted many technologies from the newcomers. With the signing of the Treaty of Waitangi, Treaty of Waitangi/Te Tiriti o Waitangi in 1840, the two cultures coexisted for a generation. Rising ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Island
The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south by the Foveaux Strait and Southern Ocean, and to the east by the Pacific Ocean. The South Island covers , making it the List of islands by area, world's 12th-largest island, constituting 56% of New Zealand's land area. At low altitudes, it has an oceanic climate. The most populous cities are Christchurch, Dunedin, Nelson, New Zealand, Nelson and Invercargill. Prior to European settlement, Te Waipounamu was sparsely populated by three major iwi – Kāi Tahu, Kāti Māmoe, and the historical Waitaha (South Island iwi), Waitaha – with major settlements including in Kaiapoi Pā near modern-day Christchurch. During the Musket Wars expanding iwi colonised Te Tau Ihu Māori, Te Tau Ihu, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiolite
An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle (Earth), upper mantle that has been uplifted and exposed, and often emplaced onto continental crustal rocks. The Greek word ὄφις, ''ophis'' (''snake'') is found in the name of ophiolites, because of the superficial texture of some of them. Serpentinite especially evokes a snakeskin. (The suffix ''-lite'' is from the Greek ''lithos'', meaning "stone".) Some ophiolites have a green color. The origin of these rocks, present in many mountainous massifs, remained uncertain until the advent of plate tectonic theory. Their great significance relates to their occurrence within mountain belts such as the Alps and the Himalayas, where they document the existence of former ocean basins that have now been consumed by subduction. This insight was one of the founding pillars of plate tectonics, and ophiolites have always played a central role in plate tectonic theory and the interpretation of ancient mo ... [...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] |
Greywacke
Greywacke or graywacke ( ) is a variety of sandstone generally characterized by its hardness (6–7 on Mohs scale), dark color, and Sorting (sediment), poorly sorted angular grains of quartz, feldspar, and small rock fragments or sand-size Lithic fragment (geology), lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic Stratum, strata. The larger Particle size (grain size), grains can be sand- to gravel-sized, and Matrix (geology), matrix materials generally constitute more than 15% of the rock by volume. Formation The origin of greywacke was unknown until turbidity currents and turbidites were understood, since, according to the normal laws of sedimentation, gravel, sand and mud should not be laid down together. Geologists now attribute its formation to submarine avalanches or strong turbidity currents. These actions churn sediment and cause mixed-sediment slurries, in which the resulting deposits may ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
