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Auckland Regional Faults
The Auckland regional geologic faults have low seismic activity, compared to much of New Zealand, but do result in an earthquake risk to the Auckland metropolitan area, New Zealand's largest city. There is also evidence of past tectonic, volcanic associations in a city located within what is, at best, a very recently dormant Auckland volcanic field. The only definite active fault in the Auckland Region, as defined geopolitically, is the Wairoa North Fault. However, there could be other possibly active faults within the Auckland region. These include the Drury Fault and the Firth of Thames Fault. Further, the adjacency of the Hauraki Rift to Auckland means that the active Kerepehi Fault with its risk of magnitude 7 or above events is relevant to seismic risk. General context As much of Auckland is located upon two volcanic fields which have been active relatively recently in the geological timescale context, evidence of active faulting could be buried under volcanic deposits. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auckland
Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by population, fifth largest city in Oceania, Auckland has an urban population of about It is located in the greater Auckland Region—the area governed by Auckland Council—which includes outlying rural areas and the islands of the Hauraki Gulf, and which has a total population of . While European New Zealanders, Europeans continue to make up the plurality of Auckland's population, the city became multicultural and Cosmopolitanism, cosmopolitan in the late-20th century, with Asian New Zealanders, Asians accounting for 31% of the city's population in 2018. Auckland has the fourth largest Foreign born, foreign-born population in the world, with 39% of its residents born overseas. With its large population of Pasifika New Zealanders, the city is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian reptiles, like the dinosaurs; an abundance of conifers and ferns; a hot Greenhouse and icehouse earth, greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since Cambrian explosion, complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest well-documented mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, Pterosaur, pterosaurs, Mosasaur, mosasaurs, and Plesiosaur, plesiosaurs. The Mesozoic was a time of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waitākere Ranges
The Waitākere Ranges is a mountain range in New Zealand. Located in West Auckland between metropolitan Auckland and the Tasman Sea, the ranges and its foothills and coasts comprise some of public and private land. The area, traditionally known to Māori as ''Te Wao Nui o Tiriwa'' (The Great Forest of Tiriwa), is of local, regional, and national significance. The Waitākere Ranges includes a chain of hills in the Auckland Region, generally running approximately from north to south, 25 km west of central Auckland. The ranges are part of the Waitākere Ranges Regional Park. From 1 May 2018 the forested areas of the Waitākere Ranges Regional Park were closed, with some exceptions, while Auckland Council upgraded the tracks to dry foot standard protect the roots and to prevent the spread of kauri dieback, bacteria that affect kauri trees and prevents them from getting nutrients, effectively killing them. There is no cure. But Etymology The name ''Wai-tākere'' origina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Auckland Volcanic Field
The South Auckland volcanic field, also known as the Franklin Volcanic Field, is an area of extinct monogenetic volcanoes around Pukekohe, the Franklin area and north-western Waikato, south of the Auckland volcanic field. The field contains at least 82 volcanoes, which erupted between 550,000 and 1,600,000 years ago. Features The field extends from Pukekiwiriki east of Papakura in the north and Pukekawa in the south. The field contains at least 82 volcanoes, and is older than the Auckland volcanic field to the north. The youngest volcanoes are likely the Bombay Hills shield volcano, which erupted an estimated 600,000 years ago, and Pukekohe Hill, the largest shield volcano of the field, which erupted an estimated 550,000 years ago. The largest tuff ring in the field is Onewhero maar which is in diameter and was formed 880,000 years ago.The field can be divided into three broad geographic areas: the north-eastern section, which consists of eroded remnants of lava flows and sco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiolite
An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level 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'' from the Greek ''lithos'' means "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 mountain belts. Pse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Description ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stokes Magnetic Anomaly
The Stokes Magnetic Anomaly (also known as the Stokes Magnetic Anomaly System, SMAS, New Zealand Junction Magnetic Anomaly, JMA, great Nelson magnetic disturbance, Junction Anomaly, Campbell Magnetic Anomaly System, CMAS) is a magnetic anomaly on the Earth's surface that extends from New Caledonia to the Chatham Rise with complexity consistent with the theory of plate tectonics. History It is named after Captain (later Admiral) John Lort Stokes by G. C. Farr in 1916 as he described it first although such naming has proved controversial, hence many of the alternative names. The magnetic declinations were observed by Captain Stokes when captaining HMS Acheron and Commander (later Admiral) Byron Drury in HMS Pandora between 1851 and 1853. Geology The Stokes Magnetic Anomaly has been characterised for over and was essential for understanding the geology of Zealandia as a mainly underwater continent. It extends from south of New Caledonia to almost the eastern edge of the Camp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunua Ranges
The Hunua Ranges is a mountain range and regional park to the southeast of Auckland city, in the Auckland and Waikato regions of New Zealand's North Island. The ranges cover some and rise to 688 metres (2255 ft) at Kohukohunui.Hunua Ranges , ''An Encyclopaedia of New Zealand'', edited by A. H. McLintock, originally published in 1966. Te Ara - The Encyclopedia of New Zealand, updated 26 September 2006. Accessed 15 March 2007. owns and manages of the ranges, including part located in the Waikato region, as a regional park open to the public. Geography The ranges are located approximately 50 kilometres (30 mi) southeast of ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy Of New Zealand
This is a list of the units into which the rock succession of New Zealand is formally divided. As new geological relationships have been discovered new names have been proposed and others are made obsolete. Not all these changes have been universally adopted. This table is based on the 2014 New Zealand Stratigraphic Lexicon (Litho2014). However, obsolete names that are still in use and names postdating the lexicon are included if it aids in understanding. Names for particular rock units have two parts, a proper name which is almost always a geographic location where the rock is found and a hierarchical rank (e.g. Waitematā Group). This ranking system starts with individual 'beds' of rock which can be grouped into 'members', members are grouped into 'formations', formations into 'subgroups' then 'groups'. In New Zealand, groups are further combined into 'supergroups' or for basement rocks into terranes. Not all of these hierarchical layers are necessarily present within a part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argillite
:''"Argillite" may also refer to Argillite, Kentucky.'' Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the 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 ''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 sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greywacke
Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume. The term "greywacke" can be confusing, since it can refer to either the immature (rock fragment) aspect of the rock or its fine-grained (clay) component. 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 mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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