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The geology of New Zealand is noted for its
volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...
activity,
earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
s and geothermal areas because of its position on the boundary of the
Australian Plate The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when India broke ...
and
Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...
s. New Zealand is part of
Zealandia Zealandia (pronounced ), also known as (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago.Gurnis, M., Hall, C.E., and Lavier, L.L., ...
, a
microcontinent Continental crustal fragments, partly synonymous with microcontinents, are pieces of continents that have broken off from main continental masses to form distinct islands that are often several hundred kilometers from their place of origin. Caus ...
nearly half the size of Australia that broke away from the
Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...
n supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique
fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
record and modern
ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
. New Zealand's
geology Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
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 South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
,
Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
,
Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
,
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
and
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. The rocks that now form the, mostly submerged, continent of Zealandia were then nestled between Eastern Australia and
Western Antarctica West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of that continent that lies within the Western Hemisphere, and includes the Antarctic Peninsula. It is separated from East Antarctica by the Transa ...
. Secondly New Zealand drifted away from Gondwana and many
sedimentary basins Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsiden ...
formed, which later became the
sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s covering the geological basement. The final phase is represented by the uplift of the
Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...
and the eruptions of the
Taupō Volcanic Zone The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward thro ...
.


Basement rocks (Cambrian-Cretaceous)

New Zealand's basement rocks range in age from mid-
Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
in north-west
Nelson Nelson may refer to: Arts and entertainment * ''Nelson'' (1918 film), a historical film directed by Maurice Elvey * ''Nelson'' (1926 film), a historical film directed by Walter Summers * ''Nelson'' (opera), an opera by Lennox Berkeley to a lib ...
to
Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
near Kaikoura. These rocks were formed in a marine environment before New Zealand separated from Gondwana. They are divided into the "Western Province", consisting mainly of
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 lit ...
,
granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...
and
gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...
, and an "Eastern Province", consisting mainly of
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 lit ...
and
schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. 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 o ...
. The provinces are further divided into
terranes In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own ...
– large slices of crust with different geological histories that have been brought together by tectonic activity (
subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...
and
strike-slip faulting In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
) to form New Zealand. The Western Province is older than the Eastern Province and outcrops along the west coast of the South Island from
Nelson Nelson may refer to: Arts and entertainment * ''Nelson'' (1918 film), a historical film directed by Maurice Elvey * ''Nelson'' (1926 film), a historical film directed by Walter Summers * ''Nelson'' (opera), an opera by Lennox Berkeley to a lib ...
to
Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, ...
. The Western Province is divided into the Buller and Takaka terranes which formed in mid-Cambrian to
Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
time (510–400 Ma). This includes New Zealand's oldest rocks,
trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...
containing greywacke, which are found in the Cobb Valley in north-west Nelson. Large sections of the Western Province have been intruded by
plutonic Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March ...
rocks or
metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...
to gneiss. These plutonic basement rocks are subdivided into the Hohonu,
Karamea Karamea is a town on the West Coast of the South Island of New Zealand. It is the northernmost settlement of any real size on the West Coast, and is located northeast by road from Westport. Apart from a narrow coastal strip, the town of Karam ...
,
Median In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic fe ...
and
Paparoa Paparoa is a settlement in Northland, New Zealand. The Paparoa Stream flows from the east, through the settlement, and into the Paparoa Creek to the south, which joins the Arapaoa River which is part of the Kaipara Harbour. State Highway 12 pa ...
batholiths. These rocks form the foundations beneath offshore
Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth Dist ...
, and much of the
West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...
, Buller, north-west
Nelson Nelson may refer to: Arts and entertainment * ''Nelson'' (1918 film), a historical film directed by Maurice Elvey * ''Nelson'' (1926 film), a historical film directed by Walter Summers * ''Nelson'' (opera), an opera by Lennox Berkeley to a lib ...
,
Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, ...
and
Stewart Island / Rakiura Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...
. Most of these plutonic rocks were formed in
Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
-
Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
time (380–335 Ma) and
Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
-
Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
time (155–100 Ma). The Median Batholith represents a long-lived batholith dividing the Western and Eastern Provinces. Before Zealandia's separation from
Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...
it stretched from
Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...
, through what is now New Zealand, into West Antarctica. It marks the site of a former subduction zone on the edge of Gondwana. The Eastern Province underlies more of New Zealand than the Western Province, including the greywacke and schist of the Southern Alps and all of the basement rocks of the North Island. The Eastern Province contains seven main terranes, the Drumduan,
Brook Street Brook Street is an axial street in the exclusive central London district of Mayfair. Most of it is leasehold, paying ground rent to and seeking lease renewals from the reversioner, that since before 1800, has been the Grosvenor Estate. Named ...
,
Murihiku Murihiku is a Māori name describing a region of the South Island in New Zealand. Traditionally it was used to describe the portion of the South Island below the Waitaki River, but now is mostly used to describe the province of Southland. The nam ...
, Dun Mountain-Maitai, Caples, Torlesse Composite (Rakaia, Aspiring and Pahau terranes) and
Waipapa Waipapa is a small town in the Bay of Islands, Northland, New Zealand. It is around 10 minutes drive from Kerikeri, the nearest urban centre to Waipapa, located on State Highway 10. Waipapa itself has no school and most people travel into Ke ...
Composite (Morrinsville and Hunua Terranes). They are mostly composed of greywacke together with
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 ...
, except for the Brook Street and Dun Mountain-Maitai Terranes which have significant igneous components (see
Dun Mountain Ophiolite Belt 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. Prehistori ...
). New Zealand's greywacke is mostly from the Caples, Torlesse Composite (Rakaia and Pahau) and Waipapa Composite (Morrinsville and Hunua) terranes formed in Carboniferous-Cretaceous time (330–120 Ma). Much of these rocks were deposited as submarine fans. They have different origins, as shown by different chemical compositions and different
fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
. In general, the sedimentary basement terranes become younger from West to East across the country, as the newer terranes were scraped off the subducting paleo-
Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...
, and accreted to the boundary of Gondwana over hundreds of millions of years. Many rocks in the Eastern Province have been metamorphosed into the Haast Schist, due to exposure to high pressures and temperatures. Rocks grade continuously from greywacke (e.g., in Canterbury) to high-grade schist (e.g., around the Caples-Torlesse boundary in
Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...
and
Marlborough Marlborough may refer to: Places United Kingdom * Marlborough, Wiltshire, England ** Marlborough College, public school * Marlborough School, Woodstock in Oxfordshire, England * The Marlborough Science Academy in Hertfordshire, England Austral ...
, and Torlesse rocks just to the East of the Alpine Fault). The Alpine Fault that corresponds to the line of the
Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...
has separated the basement rocks that used to be adjacent by about 480 km.


Separation from Gondwana (Cretaceous-Eocene)

The Australia-New Zealand continental fragment of Gondwana split from the rest of Gondwana in the late Cretaceous time (95–90 Ma). Then around 83 Ma, Zealandia started to separate from Australia forming the
Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...
, initially separating from the south. By 75 Ma, Zealandia was essentially separate from Australia and Antarctica, although only shallow seas might have separated Zealandia and Australia in the north.
Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
s continued to live in New Zealand after it separated from Gondwana, as shown by
sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...
footprints from 70 million years ago in Nelson. this meant that dinosaurs had about 20 million years to evolve unique New Zealand species. During the Cretaceous extension large normal faults formed throughout New Zealand, the Hawks Crag Breccia formed next to scarps and it has become New Zealand's best
uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
mineral deposit Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 April ...
. Currently, New Zealand has no native snakes or land mammals (other than bats). Neither marsupials nor
placental Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsup ...
mammals evolved and reached Australia in time to be on New Zealand when it drifted away 85 million years ago. The evolution and dispersal of snakes is less certain, but there is no hard evidence of them being in Australia before the opening of the Tasman Sea. The
multituberculates Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, ...
, another type of mammal which is now extinct, may have been in time to cross the land bridge to New Zealand. The landmasses continued to separate until early
Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
times (53 Ma). The Tasman Sea, and part of Zealandia then locked together with Australia to form the
Australian Plate The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when India broke ...
(40 Ma), and a new plate boundary was created between the Australian Plate and
Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...
. Zealandia ended up at a pivot point between the Pacific and Australian Plates, with spreading in the south, and convergence in the north, where the Pacific Plate was subducted beneath the Australian Plate. A precursor to the
Kermadec Arc The Tonga-Kermadec Ridge is an oceanic ridge in the south-west Pacific Ocean underlying the Tonga- Kermadec island arc. It is the most linear, fastest converging, and most seismically active subduction boundary on Earth, and consequently has the ...
was created. The convergent part of the plate boundary propagated through Zealandia from the north, eventually forming a proto-Alpine Fault in
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 recen ...
times (23 Ma). The various ridges and basins north of New Zealand relate to previous positions of the
plate boundary Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...
.


Sedimentary basins and allochthons (Cretaceous-Recent)

Erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
and deposition has led to much of Zealandia now being covered in sedimentary rocks that formed in swamps and marine sedimentary basins. Much of New Zealand was low lying around Mid
Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
-
Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...
times (40–23 Ma). Swamps became widespread, forming
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
. The land subsided further, and marine organisms produced
limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
deposits. Limestone of Oligocene-Early
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 recen ...
age formed in many areas, including the
King Country The King Country (Māori: ''Te Rohe Pōtae'' or ''Rohe Pōtae o Maniapoto'') is a region of the western North Island of New Zealand. It extends approximately from the Kawhia Harbour and the town of Otorohanga in the north to the upper reaches of ...
, known for the
Waitomo Glowworm Cave The Waitomo Glowworm Caves attraction is a cave at Waitomo on the North Island of New Zealand. It is known for its population of '' Arachnocampa luminosa,'' a glowworm species found exclusively in New Zealand. This cave is part of the waitomo ...
. In the South Island, limestone is present in Buller, Nelson, and the
West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...
, including the Pancake Rocks at
Punakaiki Punakaiki is a small village on the West Coast of the South Island of New Zealand. It is located between Westport and Greymouth on , the only through-road on the West Coast. Punakaiki is immediately adjacent to Paparoa National Park, and is a ...
in Oligocene-Early Miocene times (34–15 Ma). It is debated whether all of New Zealand was submerged at this time or if small islands remained as "arks" preserving fauna and flora. An
allochthon upright=1.6, Schematic overview of a thrust system. The hanging wall block is (when it has reasonable proportions) called a nappe. If an erosional hole is created in the nappe that is called a window (geology)">window. A klippe is a solitary out ...
is land that formed elsewhere and slid on top of other land (in other words, the material of an enormous landslide). Much of the land of Northland and
East Cape East Cape is the easternmost point of the main islands of New Zealand. It is located at the northern end of the Gisborne District of New Zealand's North Island. It can also refer to the broader Gisborne cape. East Cape was originally named "C ...
were created in this manner. Around 25–22 Ma, Northland and East Cape were adjacent, with East Cape near Whangarei. Northland-East Cape was an undersea basin. Much of the land that now forms Northland-East Cape was higher land to the Northeast (composed of rocks formed 90–25 Ma). The Pacific-Australian plate boundary was further to the Northeast, with the Pacific Plate subducting under the Australian Plate. Layers of rocks were peeled off the higher land, from the top down, and slid Southwest under the influence of gravity, to be stacked the right way up, but in reverse order. Most of the material to slide were sedimentary rocks, however, the last rocks to be slid across were slabs of
oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumu ...
(
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 i ...
s), mainly
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 ...
. Widespread volcanic activity also occurred (23–15 Ma), and is intermixed with the foreign rocks. Sedimentary basins formed on the allochthons while they were moving. East Cape was later separated from Northland and moved further south and east to its present position.


Volcanic activity

Volcanism is recorded in New Zealand throughout its whole geological history. Most volcanism in New Zealand, both modern and ancient, has been caused by the subduction of one tectonic plate under another; this causes melting in the mantle, the layer of the earth below the crust. This produces a
volcanic arc A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc lo ...
, composed of mainly
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 ...
,
andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...
and
rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
. Basaltic eruptions tend to be fairly placid, producing scoria cones and lava flows, such as the volcanic cones in the
Auckland volcanic field The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse a ...
, although
Mount Tarawera Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fissu ...
's violent 1886 eruption was an exception. Andesitic eruptions tend to form steep
stratovolcanoes A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...
, including mountains such as Ruapehu,
Tongariro Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of th ...
and
Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth Dist ...
, islands such as
Little Barrier Little is a synonym for small size and may refer to: Arts and entertainment *Little (album), ''Little'' (album), 1990 debut album of Vic Chesnutt *Little (film), ''Little'' (film), 2019 American comedy film *The Littles, a series of children's nov ...
, Whakaari / White and
Raoul Island Raoul Island (''Sunday Island'') is the largest and northernmost of the main Kermadec Islands, south south-west of 'Ata Island of Tonga and north north-east of New Zealand's North Island. It has been the source of vigorous volcanic activity ...
s, or submarine
seamount A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...
s like
Monowai Seamount Monowai Seamount is a volcanic seamount to the north of New Zealand. It is formed by a large caldera and a volcanic cone just south-southeast from the caldera. The volcanic cone rises to depths of up to but its depth varies with ongoing volcani ...
. Rhyolitic eruptions with large amounts of water tend to cause violent eruptions, producing calderas, such as
Lake Taupō Lake Taupō (also spelled Taupo; mi, Taupō-nui-a-Tia or ) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's nor ...
and
Lake Rotorua , image = Lake Rotorua.jpg , caption = Lake Rotorua , alt = Lake Rotorua , image_bathymetry = , pushpin_map=New Zealand#North Island , pushpin_map_alt = Location of Lake Rotorua , pushpin_relief=yes , caption_bathymetry = , location = R ...
. New Zealand also has many volcanoes which are not clearly related to plate subduction including the extinct
Dunedin Volcano The Dunedin Volcano is an extensively eroded multi-vent shield volcano that was active between 16 and 10 million years ago. It originally extended from the modern city of Dunedin, New Zealand to Aramoana about 25 km away. Extensive erosion has ...
and
Banks Peninsula Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves. The South Island's largest cit ...
, and the dormant
Auckland Volcanic Field The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse a ...
.


Extinct volcanoes

The South Island has no currently active volcanoes. However, in the late
Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
(100–65 Ma), there was widespread volcanic activity in Marlborough, West Coast, Canterbury and Otago; and in
Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
times (40 Ma), there was volcanic activity in
Oamaru Oamaru (; mi, Te Oha-a-Maru) is the largest town in North Otago, in the South Island of New Zealand, it is the main town in the Waitaki District. It is south of Timaru and north of Dunedin on the Pacific coast; State Highway 1 and the railway ...
. The most well known
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 recen ...
volcanic centres are the intra-plate
Dunedin Volcano The Dunedin Volcano is an extensively eroded multi-vent shield volcano that was active between 16 and 10 million years ago. It originally extended from the modern city of Dunedin, New Zealand to Aramoana about 25 km away. Extensive erosion has ...
and
Banks Peninsula Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves. The South Island's largest cit ...
s. The Dunedin Volcano which later eroded to form
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 ...
near
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 ...
was built up by a series of mainly basaltic intra-plate volcanic eruptions in Miocene times (16–10 Ma). Banks Peninsula near
Christchurch Christchurch ( ; mi, Ōtautahi) is the largest city in the South Island of New Zealand and the seat of the Canterbury Region. Christchurch lies on the South Island's east coast, just north of Banks Peninsula on Pegasus Bay. The Avon River / ...
was built from two mainly basaltic intra-plate volcanoes in Miocene times (12–6 Ma and 9.5–7.5 Ma), corresponding to the Lyttelton / Whakaraupo and Akaroa Harbours. Southland's Solander Islands / Hautere were active around 1 to 2 million years ago. There are also minor volcanic from a similar time period throughout Canterbury, Otago and also on the
Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...
. Intra-plate basaltic volcanic eruptions also occurred in the North Island, near the
Bay of Islands The Bay of Islands is an area on the east coast of the Far North District of the North Island of New Zealand. It is one of the most popular fishing, sailing and tourist destinations in the country, and has been renowned internationally for its ...
in Northland, in the Late Miocene (10 Mya), and again more recently (0.5 Mya). The
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 l ...
was active in
Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
times (1.5–0.5 Ma). The
Auckland volcanic field The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse a ...
started erupting around 250,000 years ago. It includes around 50 distinct eruptions, with most of the prominent cones formed in the last 30,000 years, and the most recent eruption, which formed
Rangitoto Island Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The wide island is a symmetrical shield volcano cone, reaching a height of . Rangitoto is the youngest and largest of the approximately 50 volcanoes of the Au ...
, around 600 years ago. The field is currently dormant and further eruptions are expected. Over time the volcanic field has slowly been drifting northwards. Volcanism in the North Island has been dominated by a series of volcanic arcs which have evolved into the still active
Taupō Volcanic Zone The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward thro ...
. Over time, volcanic activity has moved south and east, as the plate boundary moved eastward. This started in Miocene times (23 Ma) when a volcanic arc became active to the west of Northland, and gradually moved South down to
New Plymouth New Plymouth ( mi, Ngāmotu) is the major city of the Taranaki region on the west coast of the North Island of New Zealand. It is named after the English city of Plymouth, Devon from where the first English settlers to New Plymouth migrated. ...
, where
Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth Dist ...
is still active. It produced mainly andesitic strato-volcanoes. The Northland volcanoes include the volcanoes that produced the
Waipoua Plateau Waipoua Forest is a forest, on the west coast of the Northland Region of New Zealand's North Island. It preserves some of the best examples of kauri forest remaining in New Zealand. It is notable for having two of the largest living kauri tr ...
(site of the
Waipoua Forest Waipoua Forest is a forest, on the west coast of the Northland Region of New Zealand's North Island. It preserves some of the best examples of kauri forest remaining in New Zealand. It is notable for having two of the largest living kauri tre ...
) and the
Kaipara Volcano Kaipara may refer to: * Kaipara Flats, a locality in the Rodney District of New Zealand * Kaipara (New Zealand electorate), a former Parliamentary electorate *Kaipara District, a local government division in New Zealand *Kaipara Harbour Kaipara ...
. The Waitakere Volcano (22–16 Ma) has mainly been eroded, but conglomerate from the volcano forms the
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 kno ...
, and produced most of the material that makes up the
Waitemata sandstones Waitemata or Waitematā may refer to: * Waitematā Harbour, the primary harbour of Auckland, New Zealand * Waitematā (local board area), a local government area in Auckland, New Zealand ** Waitematā Local Board, a local board of Auckland Council, ...
and mudstones.
Lahars A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extremel ...
produced the coarser Parnell Grit. Notable visible volcanoes in the Waikato include
Karioi Karioi or Mount Karioi is a 2.4 million year old extinct stratovolcano SW of Raglan in the Waikato region of New Zealand's North Island. It was the earliest of the line of 6 calcalkalic volcanoes, the largest of which is Mount Pirongia (the oth ...
and
Pirongia Pirongia is a small town in the Waipa District of the Waikato region of New Zealand's North Island. It is 12 kilometres to the west of Te Awamutu, on the banks of the Waipā River, close to the foot of the 962 metre Mount Pirongia, which lies i ...
(2.5 Ma). The volcanoes off the West coast of the North Island, together with Taranaki and the Tongariro Volcanic Centre, are responsible for the black iron sand on many of the beaches between Taranaki and
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 po ...
. Shortly after (18 Ma), a volcanic arc developed further east to create the
Coromandel Range A true-colour image showing Auckland city (left), the Hauraki Gulf (centre) and the Coromandel Peninsula (right). The scene was acquired by NASA's Terra satellite, on October 23, 2002. The Coromandel Range is a mountain range running the length ...
s and undersea
Colville Ridge Colville may refer to: Places Canada *Colville Lake (Northwest Territories), a lake in Northwest Territories *Colville Lake, Northwest Territories, a settlement corporation * Colville Range, a small mountain range in southwestern British Colum ...
. The initial activity was andesitic but later became rhyolitic (12 Ma). In the
Kauaeranga Valley Kauaeranga Valley is a valley created by the Kauaeranga River, which flows from the Coromandel Range southwest to the Firth of Thames at Thames, New Zealand in the North Island. It contains the settlement of Kauaeranga () on the Coromandel Penin ...
,
volcanic plugs A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged mag ...
remain, as does a lava lake that now forms the top of
Table Mountain Table Mountain ( naq, Huriǂoaxa, lit= sea-emerging; af, Tafelberg) is a flat-topped mountain forming a prominent landmark overlooking the city of Cape Town in South Africa. It is a significant tourist attraction, with many visitors using the ...
. Active geothermal systems, similar to those that now exist near
Rotorua Rotorua () is a city in the Bay of Plenty region of New Zealand's North Island. The city lies on the southern shores of Lake Rotorua, from which it takes its name. It is the seat of the Rotorua Lakes District, a territorial authority encompass ...
, were present around 6 Ma, and produced the
gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
and
silver Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
deposits that were later mined in the
Coromandel gold rush The Coromandel Gold Rushes on the Coromandel Peninsula and around the nearby towns of Thames and Waihi in New Zealand in the nineteenth century were moderately successful. Traces of gold were found about 1842. A small find was made near Coromandel i ...
. Later (5–2 Ma), volcanic activity moved further south to form the
Kaimai Range The Kaimai Range (sometimes referred to as the ''Kaimai Ranges'') is a mountain range in the North Island of New Zealand. It is part of a series of ranges, with the Coromandel Range to the north and the Mamaku Ranges to the south. The Kaimai Ra ...
.


Active volcanoes and geothermal areas

After this, activity shifted further East to the Taupō Volcanic Zone, which runs from the
Tongariro Volcanic Centre The North Island Volcanic Plateau (often called the Central Plateau and occasionally the Waimarino Plateau) is a volcanic plateau covering much of central North Island of New Zealand with volcanoes, lava plateaus, and crater lakes. It contains t ...
( Ruapehu and
Tongariro Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of th ...
), through
Taupō Taupō (), sometimes written Taupo, is a town on the north-eastern shore of Lake Taupō, New Zealand's largest lake, in the central North Island. It is the largest urban area of the Taupō District, and the second-largest urban area in the Wa ...
,
Rotorua Rotorua () is a city in the Bay of Plenty region of New Zealand's North Island. The city lies on the southern shores of Lake Rotorua, from which it takes its name. It is the seat of the Rotorua Lakes District, a territorial authority encompass ...
, and out to sea to form the Kermadec Ridge. Activity was initiated around 2 Ma, and continues to this day. The Tongariro Volcanic Centre is composed of andesitic volcanoes, while the areas around Taupō and Rotorua are largely rhyolitic with minor basalt. Early eruptions between Taupō and Rotorua around 1.25 Ma, and 1 Ma, were large enough to produce an
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 surrou ...
sheet that reached
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 po ...
, Napier, and Gisborne. This includes vast
pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular vol ...
deposits generated from eruptions in the Taupō Volcanic Zone occur throughout the central North Island, Bay of Plenty,
Waikato Waikato () is a Regions of New Zealand, local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton, New Zealand, Hamilton City ...
,
King Country The King Country (Māori: ''Te Rohe Pōtae'' or ''Rohe Pōtae o Maniapoto'') is a region of the western North Island of New Zealand. It extends approximately from the Kawhia Harbour and the town of Otorohanga in the north to the upper reaches of ...
and
Manawatū-Whanganui Manawatū-Whanganui (; spelled Manawatu-Wanganui prior to 2019) is a region in the lower half of the North Island of New Zealand, whose main population centres are the cities of Palmerston North and Whanganui. It is administered by the Manawat ...
regions. Every so often, there are swarms of
earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
within an area of the Taupō Volcanic Zone, which last for years. These earthquake swarms indicate that some movement of
magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
is occurring below the surface. While they have not resulted in an eruption in recent times, there is always the potential for a new volcano to be created, or a dormant volcano to come to life. The Tongariro Volcanic Centre developed over the last 275,000 years and contains the active andesitic volcanic cones of Ruapehu, Tongariro, and
Ngauruhoe Mount Ngāuruhoe (also spelled Ngauruhoe; Māori: ''Ngāuruhoe'') is a volcanic cone in New Zealand. It is the youngest vent in the Tongariro stratovolcano complex on the Central Plateau of the North Island and first erupted about 2,500  ...
(really a side cone of Tongariro). Ruapehu erupts about once a decade, and while the eruptions cause havoc for skiers, plane flights and hydroelectric dams, the eruptions are relatively minor. However, the sudden collapse of the crater wall caused major problems when it generated a
lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extreme ...
in 1953, that destroyed a rail bridge, and caused 151 deaths at
Tangiwai Tangiwai is a census area and a small rural community in the Ruapehu District of the Manawatū-Whanganui region of New Zealand's North Island. It is located east of Ohakune and Rangataua and west of Waiouru on State Highway 49. In 2018 37.5% ...
. The last significant eruption was 1995–96. Ngauruhoe last erupted 1973–75. Taranaki is a perfectly formed andesitic strato-volcano, that last erupted in 1755.
Lake Taupō Lake Taupō (also spelled Taupo; mi, Taupō-nui-a-Tia or ) is a large crater lake in New Zealand's North Island, located in the caldera of the Taupō Volcano. The lake is the namesake of the town of Taupō, which sits on a bay in the lake's nor ...
, the largest lake in the North Island, is a
volcanic caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
, responsible for rhyolitic eruptions about once every 1,000 years. The largest eruption in the last 65,000 years was the cataclysmic
Oruanui Eruption The Oruanui eruption of New Zealand's Taupō Volcano (also known as the Kawakawa eruption or Kawakawa/Oruanui event) was the world's most recent Supervolcano#Known supereruptions, supereruption.} Eruption With a Volcanic Explosivity Index of 8, ...
26,500 years ago, producing 530 cubic kilometres of magma. The most recent eruption, around 233 AD was also a major event, the biggest eruption worldwide in the last 5,000 years. The eruption caused a pyroclastic flow that devastated the land from
Waiouru Waiouru is a small town in the Ruapehu District, in New Zealand's Manawatū-Whanganui region. It is located on the south-eastern North Island Volcanic Plateau, north of Palmerston North and 25 kilometres south-east of Mount Ruapehu. The town ...
to
Rotorua Rotorua () is a city in the Bay of Plenty region of New Zealand's North Island. The city lies on the southern shores of Lake Rotorua, from which it takes its name. It is the seat of the Rotorua Lakes District, a territorial authority encompass ...
in 10 minutes. The Ōkataina Volcanic Centre, to the East of Rotorua, is also responsible for major cataclysmic rhyolitic eruptions. The last eruption, of Tarawera and
Lake Rotomahana Lake Rotomahana is an lake in northern New Zealand, located 20 kilometres to the south-east of Rotorua. It is immediately south-west of the dormant volcano Mount Tarawera, and its geography was substantially altered by a major 1886 eruption of ...
in 1886, was a relatively minor eruption, which was thought to have destroyed the famous
Pink and White Terraces The Pink and White Terraces ( and ), were natural wonders of New Zealand. They were reportedly the largest silica sinter deposits on earth. Until recently, they were lost and thought destroyed in the 1886 eruption of Mount Tarawera, while new hy ...
, and covered much of the surrounding countryside in ash, killing over 100 people. In 2017 researchers rediscovered the locations of the Pink and White Terraces using a forgotten survey from 1859. Many lakes around Rotorua are calderas from rhyolitic eruptions. For example,
Lake Rotorua , image = Lake Rotorua.jpg , caption = Lake Rotorua , alt = Lake Rotorua , image_bathymetry = , pushpin_map=New Zealand#North Island , pushpin_map_alt = Location of Lake Rotorua , pushpin_relief=yes , caption_bathymetry = , location = R ...
erupted around 13,500 years ago. A line of undersea volcanoes extends out along the
Kermadec Ridge The Tonga-Kermadec Ridge is an oceanic ridge in the south-west Pacific Ocean underlying the Tonga- Kermadec island arc. It is the most linear, fastest converging, and most seismically active subduction boundary on Earth, and consequently has the ...
.
Whakaari / White Island Whakaari / White Island (, mi, Te Puia Whakaari, lit. "the dramatic volcano"), also known as White Island or Whakaari, is an active andesite stratovolcano situated from the east coast of the North Island of New Zealand, in the Bay of Plent ...
, in the Bay of Plenty, represents the southern end of this chain and is a very active andesitic volcano, erupting with great frequency. It has the potential to cause a tsunami in the Bay of Plenty, as does the dormant
Mayor Island / Tūhua Mayor Island / Tūhua is a dormant shield volcano located off the Bay of Plenty coast of New Zealand's North Island. It lies north of Tauranga and covers . Geography The island is quite steep along its coast and rises to above sea level. A ...
volcano. The Taupō Volcanic Zone is known for its geothermal activity. For example, Rotorua and the surrounding area have many areas with
geysers A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...
,
silica terrace Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
s,
fumaroles A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...
, mud-pools,
hot springs A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
, etc. Notable geothermal areas include
Whakarewarewa Whakarewarewa (reduced version of Te Whakarewarewatanga O Te Ope Taua A Wahiao, meaning ''The gathering place for the war parties of Wahiao'', often abbreviated to Whaka by locals) is a Rotorua semi-rural geothermal area in the Taupo Volcanic ...
,
Tikitere Tikitere, also known as "Hell's Gate", is a suburb in Rotorua's most active geothermal area on New Zealand State Highway 30, State Highway 30, between Lake Rotorua and Lake Rotoiti (Bay of Plenty), Lake Rotoiti in the Bay of Plenty, New Zealand ...
, Waimangu,
Waiotapu Waiotapu (Māori language, Māori for "sacred waters") is an active Geothermal (geology), geothermal area at the southern end of the Okataina Volcanic Centre, just north of the Reporoa caldera, in New Zealand's Taupo Volcanic Zone. It is 27 kilo ...
, Craters of the Moon and
Orakei Korako Orakei Korako is a highly active geothermal area most notable for its series of fault-stepped sinter terraces, located in a valley north of Taupō on the banks of the Waikato River in the Taupō Volcanic Zone, New Zealand. It is also known as ...
. Geothermal energy is used to generate electricity at
Wairakei Wairakei is a small settlement, and geothermal area a few kilometres north of Taupō, in the centre of the North Island of New Zealand, on the Waikato River. It is part of the Taupō Volcanic Zone and features several natural geysers, hot pool ...
, near
Taupō Taupō (), sometimes written Taupo, is a town on the north-eastern shore of Lake Taupō, New Zealand's largest lake, in the central North Island. It is the largest urban area of the Taupō District, and the second-largest urban area in the Wa ...
. Hot pools abound throughout New Zealand. Geothermal energy is used to generate electricity in the Taupō Volcanic Zone.


Modern tectonic setting and earthquakes

New Zealand is currently astride the convergent boundary between the Pacific and Australian Plates. Over time, the relative motion of the plates has altered and the current configuration is geologically recent. Currently the Pacific Plate is subducted beneath the Australian Plate from around
Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
in the north, through the Tonga Trench,
Kermadec Trench The Kermadec Trench is a linear ocean trench in the south Pacific Ocean. It stretches about from the Louisville Seamount Chain in the north (26°S) to the Hikurangi Plateau in the south (37°S), north-east of New Zealand's North Island. Toget ...
, and Hikurangi Trough to the east of the
North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...
of New Zealand, down to
Cook Strait Cook Strait ( mi, Te Moana-o-Raukawa) separates the North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is wide at its narrowest point,McLintock, A H, ...
. Through most of the
South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...
, the plates slide past each other (
Alpine Fault The Alpine Fault is a geological fault that runs almost the entire length of New Zealand's South Island (c. 480 km) and forms the boundary between the Pacific Plate and the Indo-Australian Plate. The Southern Alps have been uplifted on the f ...
), with slight
obduction Obduction is a geological process whereby denser oceanic crust (and even upper mantle) is scraped off a descending ocean plate at a convergent plate boundary and thrust on top of an adjacent plate. When oceanic and continental plates converge, ...
of the Pacific Plate over the Australian Plate, forming
Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...
. From
Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, ...
south, the Australian Plate subducts under the Pacific Plate forming the
Puysegur Trench The deepStern, Robert J. (2004)Subduction initiation: spontaneous and induced Earth and Planetary Science Letters 226, 275–292. . Puysegur Trench is a deep cleft in the floor of the south Tasman Sea formed by the subduction of the Indo-Austral ...
. This configuration has led to volcanism and extension in the North Island forming the Taupō Volcanic Zone and uplift in the South Island forming the Southern Alps. The Pacific Plate is colliding with the Australian Plate at a rate of about 40 mm/yr. The East coast of the North Island is being compressed and lifted by this collision, producing the
North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...
and
Marlborough Fault System The Marlborough Fault System is a set of four large dextral strike-slip faults and other related structures in the northern part of South Island, New Zealand, which transfer displacement between the mainly transform plate boundary of the Alpine ...
s. The East Coast of the North Island is also rotating clockwise, relative to Northland,
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 po ...
and
Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth Dist ...
, stretching the
Bay of Plenty The Bay of Plenty ( mi, Te Moana-a-Toi) is a region of New Zealand, situated around a bight of the same name in the northern coast of the North Island. The bight stretches 260 km from the Coromandel Peninsula in the west to Cape Runawa ...
, and producing the
Hauraki Rift The Hauraki Rift is an active NeS-to NWeSE-striking rift valley system in the North Island of New Zealand that has produced the Firth of Thames and the Hauraki Plains. It is approximately wide and long. Geology The rift valley in the north a ...
(Hauraki Plains and Hauraki Gulf) and Taupō Volcanic Zone. The East Coast of the South Island is sliding obliquely towards the Alpine Fault, relative to
Westland Westland or Westlands may refer to: Places *Westlands, an affluent neighbourhood in the city of Nairobi, Kenya * Westlands, Staffordshire, a suburban area and ward in Newcastle-under-Lyme *Westland, a peninsula of the Shetland Mainland near Vaila ...
, causing the Southern Alps to rise about 10 mm/yr (although they are also worn down at a similar rate). The
Hauraki Plains The Hauraki Plains are a geographical feature and non-administrative area (though Hauraki Plains County Council existed from 1920 to 1989 and a statistical Area Unit remains) located in the northern North Island of New Zealand, at the lower ( ...
,
Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...
, Bay of Plenty,
Marlborough Sounds The Marlborough Sounds are an extensive network of sea-drowned valleys at the northern end of the South Island of New Zealand. The Marlborough Sounds were created by a combination of land subsidence and rising sea levels. According to Māori m ...
, and
Christchurch Christchurch ( ; mi, Ōtautahi) is the largest city in the South Island of New Zealand and the seat of the Canterbury Region. Christchurch lies on the South Island's east coast, just north of Banks Peninsula on Pegasus Bay. The Avon River / ...
are sinking. The Marlborough Sounds are known for their sunken mountain ranges. As
Wellington Wellington ( mi, Te Whanganui-a-Tara or ) is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the second-largest city in New Zealand by me ...
rises, and Marlborough sinks,
Cook Strait Cook Strait ( mi, Te Moana-o-Raukawa) separates the North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is wide at its narrowest point,McLintock, A H, ...
is being shifted further south. Great
stress Stress may refer to: Science and medicine * Stress (biology), an organism's response to a stressor such as an environmental condition * Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
is built up in the earth's crust due to the constant movement of the tectonic plates. This stress is released by
earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
s, which can occur on the plate boundary or on any of thousands of smaller faults throughout New Zealand. Because the Pacific Plate is subducting under the eastern side of the North Island, there are frequent deep earthquakes east of a line from the Bay of Plenty to Nelson (the approximate edge of the subducted plate), with the earthquakes being deeper to the west, and shallower to the east. Because the Australian Plate is subducting under the Pacific Plate in
Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, ...
, there are frequent deep earthquakes near Fiordland, with the earthquakes being deeper to the east and shallower near the west. Shallow earthquakes are more widespread, occurring almost everywhere throughout New Zealand (especially the Bay of Plenty,
East Cape East Cape is the easternmost point of the main islands of New Zealand. It is located at the northern end of the Gisborne District of New Zealand's North Island. It can also refer to the broader Gisborne cape. East Cape was originally named "C ...
to Marlborough, and Alpine Fault). However, Northland,
Waikato Waikato () is a Regions of New Zealand, local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton, New Zealand, Hamilton City ...
, and
Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...
are relatively stable.
Canterbury Canterbury (, ) is a City status in the United Kingdom, cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour, Kent, River Stour. ...
had been without a major earthquake in recorded history until the 7.1 Canterbury earthquake on 4 September 2010. The volcanic activity in the central North island also creates many shallow earthquakes.


Paleoclimate of New Zealand

Since Zealandia separated from Gondwana (80 mya) in the Cretaceous the climate has typically been far warmer than today. However, since the
Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago) and is ongoing. Although geologists describe ...
(2.9 mya) Zealandia has experienced climate either cooler or only slightly warmer than today. In the Cretaceous, New Zealand was positioned at 80 degrees south at the boundary between Antarctica and Australia. But it was covered in trees as the climate of 90 million years ago was much warmer and wetter than today. During the warm Eocene Period vast swamps covered New Zealand which became coal seams in Southland and
Waikato Waikato () is a Regions of New Zealand, local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton, New Zealand, Hamilton City ...
. In the Miocene there are
paleontological Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of foss ...
records of warm lakes in Central Otago with palm trees and small land mammals. Over the past 30,000 years three major climate events are recorded in New Zealand, the last glacial maximum's coldest period from 28 to 18,000 years ago, a transitional period from 18 to 11,000 years ago and the Holocene Inter Glacial which has been occurring for the past 11,000 years. Throughout the last glacial maximum, global sea levels were about lower than present levels. When this happened the North Island, South Island, and
Stewart Island Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...
were joined. Temperatures dropped by about 4–5 °C. Much of the
Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...
and
Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lakes, ...
were glaciated, but the rest of New Zealand was largely ice-free. The land to the North of
Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...
was forested, but much of the rest of New Zealand was covered in grass or shrubs, due to the cold and dry climate. This lack of vegetation cover lead to greater wind erosion and the deposition of
loess Loess (, ; from german: Löss ) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loess or similar deposits. Loess is a periglacial or aeolian ...
(windblown dust). The study of New Zealand's paleoclimate has settled some of the debate regarding links between the Little Ice Age (LIA) in the Northern Hemisphere and the climate in New Zealand at the same time. The key facts to emerge are that New Zealand did experience a noticeable cooler climate, but at a slightly later date than in the
Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
.


Geological hazards

New Zealand suffers from many natural hazards, including
earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
and
tsunamis A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater expl ...
, volcanic and hydrothermal eruptions and
landslides Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, ...
. The largest earthquake in New Zealand was an M8.2 event in the
Wairarapa The Wairarapa (; ), a geographical region of New Zealand, lies in the south-eastern corner of the North Island, east of metropolitan Wellington and south-west of the Hawke's Bay Region. It is lightly populated, having several rural service ...
, in 1855, and the most deaths (261) occurred in a M7.8 earthquake in
Hawkes Bay Hawke's Bay ( mi, Te Matau-a-Māui) is a local government region on the east coast of New Zealand's North Island. The region's name derives from Hawke Bay, which was named by Captain James Cook in honour of Admiral Edward Hawke. The region is ...
in 1931. Widespread property damage was caused by the
2010 Canterbury earthquake The 2010 Canterbury earthquake (also known as the Darfield earthquake) struck the South Island of New Zealand with a moment magnitude of 7.1 at on , and had a maximum perceived intensity of X (''Extreme'') on the Mercalli intensity scale. Som ...
, which measured 7.1; The M6.3 aftershock of 22 February 2011 ( 2011 Canterbury earthquake) resulted in 185 fatalities. Most recently, the M7.8 Kaikōura earthquake struck just after midnight on November 14, 2016, killing two people in the remote Kaikoura area northeast of Christchurch. Numerous aftershocks of M5.0 or greater are spread over a large area between Wellington and Culverden. New Zealand is at risk from tsunamis that are generated from both local and international faults. The eastern coast of New Zealand is most at risk as the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
is more tectonically active than the
Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...
. Locally the faults along the North Island's east coast provide the greatest risk. Minor tsunamis have occurred in New Zealand from earthquakes in Chile, Alaska and Japan. There are many potentially dangerous volcanoes in the Taupō Volcanic Zone. The most severe volcanic eruption since the arrival of Europeans is the Tarawera eruption in 1886. A
lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extreme ...
from Mount Ruapehu destroyed a bridge and derailed a train in December 1953, killing 151 people. Even a minor eruption at Ruapehu could cause the loss of electricity for Auckland, due to ash on the power lines, and in the
Waikato River The Waikato River is the longest river in New Zealand, running for through the North Island. It rises on the eastern slopes of Mount Ruapehu, joining the Tongariro River system and flowing through Lake Taupō, New Zealand's largest lake. It th ...
(stopping the generation of hydroelectric power). Many parts of New Zealand are susceptible to landslides, particularly due to deforestation and the high earthquake risk. Much of the North Island is steep, and composed of soft mudstone known as papa, that easily generates landslides.


Geological resources

New Zealand main geological resources are coal, gold, oil, and natural gas.
Coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
has been mined in Northland, the
Waikato Waikato () is a Regions of New Zealand, local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton, New Zealand, Hamilton City ...
, Taranaki, Nelson and Westland, Canterbury, Otago, and Southland. The
West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...
contains some of New Zealand's best
bituminous coal Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It ...
. The largest coal deposits occur in Southland.
Gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
has been mined in the
Coromandel Coromandel may refer to: Places India *Coromandel Coast, India **Presidency of Coromandel and Bengal Settlements ** Dutch Coromandel *Coromandel, KGF, Karnataka, India New Zealand *Coromandel, New Zealand, a town on the Coromandel Peninsula *Coro ...
and
Kaimai Range The Kaimai Range (sometimes referred to as the ''Kaimai Ranges'') is a mountain range in the North Island of New Zealand. It is part of a series of ranges, with the Coromandel Range to the north and the Mamaku Ranges to the south. The Kaimai Ra ...
s (especially the
Martha Mine The Martha Mine is a gold mine in the New Zealand town of Waihi. Since July 2015 it has been owned by Australian-based OceanaGold. History William Nicholl marked out a claim, calling it "Martha" after a family member. Several smaller claims wer ...
at
Waihi Waihi is a town in Hauraki District in the North Island of New Zealand, especially notable for its history as a gold mine town. The town is at the foot of the Coromandel Peninsula, close to the western end of the Bay of Plenty. The nearby res ...
),
Westland Westland or Westlands may refer to: Places *Westlands, an affluent neighbourhood in the city of Nairobi, Kenya * Westlands, Staffordshire, a suburban area and ward in Newcastle-under-Lyme *Westland, a peninsula of the Shetland Mainland near Vaila ...
,
Central Otago Central Otago is located in the inland part of the Otago region in the South Island of New Zealand. The motto for the area is "A World of Difference". The area is dominated by mountain ranges and the upper reaches of the Clutha River and tributa ...
, and Eastern Otago (especially
Macraes Mine Macraes Mine in East Otago is New Zealand's largest gold mine, and consists of a large scale opencast mine opened in 1990, and a newer underground mine, opened in 2008.Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth Dist ...
area, but many other offshore areas have the potential for deposits.
Iron sand Ironsand, also known as iron-sand or iron sand, is a type of sand with heavy concentrations of iron. It is typically dark grey or blackish in colour. It is composed mainly of magnetite, Fe3O4, and also contains small amounts of titanium, silic ...
is also plentiful on the west coast from Taranaki to
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 po ...
.
Jade Jade is a mineral used as jewellery or for ornaments. It is typically green, although may be yellow or white. Jade can refer to either of two different silicate minerals: nephrite (a silicate of calcium and magnesium in the amphibole group of ...
(
Pounamu Pounamu is a term for several types of hard and durable stone found in southern 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 , also used ...
in
Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...
) from South Island
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 i ...
s continues to be extracted, mostly from
alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...
, and worked for sale.
Groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...
reservoirs are extracted throughout the country, but are particularly valuable in the dryer eastern regions of both the North and South Islands.


History of New Zealand geology

The detailed study of New Zealand's geology began with
Julius von Haast Sir Johann Franz Julius von Haast (1 May 1822 – 16 August 1887) was a German-born New Zealand explorer, geologist, and founder of the Canterbury Museum in Christchurch. Early life Johann Franz Julius Haast was born on 1 May 1822 in Bo ...
and
Ferdinand von Hochstetter Christian Gottlieb Ferdinand Ritter von Hochstetter (30 April 1829 – 18 July 1884) was a German-Austrian geologist. Career Having received his early education at the evangelical seminary at Maulbronn, Ferdinand proceeded to the University o ...
who created numerous regional
geological map A geologic map or geological map is a special-purpose map made to show various geological features. Rock (geology), Rock units or stratum, geologic strata are shown by color or symbols. Bed (geology), Bedding planes and structural features such ...
s of the country during resource exploration in the mid-late 1800s. In 1865
James Hector Sir James Hector (16 March 1834 – 6 November 1907) was a Scottish-New Zealand geologist, naturalist, and surgeon who accompanied the Palliser Expedition as a surgeon and geologist. He went on to have a lengthy career as a government employe ...
was appointed to found the
Geological Survey of New Zealand GNS Science ( mi, Te Pū Ao), officially registered as the Institute of Geological and Nuclear Sciences Limited, is a New Zealand Crown Research Institute. It focuses on geology, geophysics (including seismology and volcanology), and nuclear sc ...
. Patrick Marshall coined the terms '' andesite line'' and ''
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 surrou ...
'' in the early 1900s while working in the Taupō Volcanic Zone. Harold Wellman discovered the Alpine Fault and its 480 km offset in 1941. Even though Wellman proved that large blocks of land could move considerable distances, the New Zealand geological survey was largely a late adopter of plate tectonics. Charles Cotton became an international authority on
geomorphology Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or n ...
using New Zealand active tectonics and variable climate to create universally applicably rules. His major works becoming standard text books in New Zealand and overseas. Charles Fleming established the Wanganui Basin as a classic site for studying past sea levels and climates. In 1975 the
palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
Joan Wiffen Joan Wiffen (née Pederson, 4 February 1922 – 30 June 2009) was a self-taught New Zealand paleontologist known for discovering the first dinosaur fossils in New Zealand. Early life Wiffen was born in 1922 and was brought up in Havelock No ...
discovered the first dinosaur fossils in New Zealand. The Geological Survey of New Zealand now known as
GNS Science GNS Science ( mi, Te Pū Ao), officially registered as the Institute of Geological and Nuclear Sciences Limited, is a New Zealand Crown Research Institute. It focuses on geology, geophysics (including seismology and volcanology), and nuclear sc ...
has done extensive mapping through New Zealand at 1:250,000 and 1:50:000 scales. The most modern map series are the "QMAPs" at 1:250,000. New Zealand's geological research is published by GNS Science, in the New Zealand Journal of Geology and Geophysics, and internationally. A Map showing the distribution of earthquakes in New Zealand can be obtained from Te Ara: The Encyclopedia of New Zealand. Current earthquake and volcanic activity can be obtained from the GeoNet website.Geonet
– Current New Zealand Earthquake and Volcanic Activity.
The universities of
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 po ...
,
Canterbury Canterbury (, ) is a City status in the United Kingdom, cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour, Kent, River Stour. ...
,
Massey Massey may refer to: Places Canada * Massey, Ontario * Massey Island, Nunavut New Zealand * Massey, New Zealand, an Auckland suburb United States * Massey, Alabama * Massey, Iowa * Massey, Maryland People * Massey (surname) Educati ...
,
Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...
,
Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...
and
Waikato Waikato () is a Regions of New Zealand, local government region of the upper North Island of New Zealand. It covers the Waikato District, Waipa District, Matamata-Piako District, South Waikato District and Hamilton, New Zealand, Hamilton City ...
are activity engaged in geological research in New Zealand,
Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
, the wider South Pacific and elsewhere.


See also

*
Alpine Fault The Alpine Fault is a geological fault that runs almost the entire length of New Zealand's South Island (c. 480 km) and forms the boundary between the Pacific Plate and the Indo-Australian Plate. The Southern Alps have been uplifted on the f ...
*
Geography of New Zealand New Zealand ( mi, Aotearoa) is an island country located in the south-western Pacific Ocean, near the centre of the water hemisphere. It consists of a large number of islands, estimated around 700, mainly remnants of a larger land mass now b ...
*
Hikurangi Trench The Hikurangi Trench, also called the Hikurangi Trough, is an oceanic trench in the bed of the Pacific Ocean off the east coast of the North Island of New Zealand, lying between the southern end of the Cook Strait and the Chatham Rise. It is the ...
*
Indo-Australian Plate The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
* Kaikōura Canyon * List of dinosaurs of New Zealand *
List of earthquakes in New Zealand This is a list of large earthquakes that have occurred in New Zealand. Only earthquakes with a magnitude of 6.0 or greater are listed, except for a few that had a moderate impact. Aftershocks are not included, unless they were of great signifi ...
* List of rock formations in New Zealand *
Marlborough Fault System The Marlborough Fault System is a set of four large dextral strike-slip faults and other related structures in the northern part of South Island, New Zealand, which transfer displacement between the mainly transform plate boundary of the Alpine ...
*
Natural history of New Zealand The natural history of New Zealand began when the landmass Zealandia broke away from the supercontinent Gondwana in the Cretaceous period. Before this time, Zealandia shared its past with Australia and Antarctica. Since this separation, the New Z ...
*
New Zealand geologic time scale While also using the international geologic time scale, many nations–especially those with isolated and therefore non-standard prehistories–use their own systems of dividing geologic time into epochs and faunal stages. In New Zealand, these epo ...
*
North Island Fault System The North Island Fault System (also known as North Island Dextral Fault Belt or NIFS) is a set of southwest–northeast trending seismically-active faults in the North Island of New Zealand that carry most of the dextral (right lateral) strike- ...
*
Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Iza ...
*
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 unive ...
*
Zealandia (continent) Zealandia (pronounced ), also known as ( Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago.Gurnis, M., Hall, C.E., and Lavier, L.L. ...


Regional geology

*
Geology of the Northland Region New Zealand's Northland Region is built upon a basement consisting mainly of greywacke rocks, which are exposed on the eastern side of the peninsula. In-place Eocene coal measures crop out at Kamo, near Whangarei, and Oligocene limestone crops ...
*
Geology of the Auckland Region The Auckland Region of New Zealand is built on a basement of greywacke rocks that form many of the islands in the Hauraki Gulf, the Hunua Ranges, and land south of Port Waikato. The Waitākere Ranges in the west are the remains of a large andesi ...
**
Auckland volcanic field The Auckland volcanic field is an area of monogenetic volcanoes covered by much of the metropolitan area of Auckland, New Zealand's largest city, located in the North Island. The approximately 53 volcanoes in the field have produced a diverse a ...
* Geology of the Waikato-King Country Region *
Taupō Volcanic Zone The Taupō Volcanic Zone (TVZ) is a volcanic area in the North Island of New Zealand that has been active for the past two million years and is still highly active. Mount Ruapehu marks its south-western end and the zone runs north-eastward thro ...
**
Whakaari / White Island Whakaari / White Island (, mi, Te Puia Whakaari, lit. "the dramatic volcano"), also known as White Island or Whakaari, is an active andesite stratovolcano situated from the east coast of the North Island of New Zealand, in the Bay of Plent ...
**
Rotorua Caldera The Rotorua Caldera, now in filled with Lake Rotorua, is a large rhyolitic caldera. It is one of several large volcanoes located in the Taupō Volcanic Zone on the North Island of New Zealand. Geography The major regional settlement of Rotor ...
**
Mount Tarawera Mount Tarawera is a volcano on the North Island of New Zealand within the older but volcanically productive Ōkataina Caldera. Located 24 kilometres southeast of Rotorua, it consists of a series of rhyolitic lava domes that were fissu ...
**
Taupō Volcano Lake Taupō, in the centre of New Zealand's North Island, is the caldera of the Taupō Volcano, a large rhyolitic supervolcano. This huge volcano has produced two of the world's most violent eruptions in geologically recent times. ImageSize ...
**
Mount Tongariro Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of th ...
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Mount Ngauruhoe Mount Ngāuruhoe (also spelled Ngauruhoe; Māori: ''Ngāuruhoe'') is a volcanic cone in New Zealand. It is the youngest vent in the Tongariro stratovolcano complex on the Central Plateau of the North Island and first erupted about 2,500 y ...
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Mount Ruapehu Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tongari ...
* Geology of the Raukumara Region *
Geology of Taranaki The Taranaki Region of New Zealand is built upon the Median Batholith in the West, and Greywacke Rocks in the East. However, no rocks older than Miocene times are visible at the surface. The dominant feature of the Taranaki Region is the andesitic ...
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Mount Taranaki Mount Taranaki (), also known as Mount Egmont, is a dormant stratovolcano in the Taranaki region on the west coast of New Zealand's North Island. It is the second highest point in the North Island, after Mount Ruapehu. The mountain has a seco ...
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Geology of the Wellington Region The Wellington Region of New Zealand has a foundation of Torlesse Greywacke rocks, that make up the Tararua and Rimutaka Ranges, that go from Wellington in the south to the Manawatū Gorge, where they are renamed as the Ruahine Ranges, and contin ...
* Geology of the Tasman District * Geology of Canterbury, New Zealand *
Geology of the West Coast Region The geology of the West Coast of New Zealand's South Island is divided in two by the Alpine Fault, which runs through West Coast, New Zealand, the Region in a North-East direction. To the West of the fault Paleozoic basement rocks are interluded b ...


References


Further reading

*Graham, Ian J. et al.;''A continent on the move : New Zealand geoscience into the 21st century'' – The Geological Society of New Zealand in association with GNS Science, 2008. *Campbell, Hamish; Hutching, Gerard; ''In Search of Ancient New Zealand'', Penguin Books in association with GNS Science, 2007, *Te Ara: The Encyclopedia of New Zealan
An Overview of New Zealand Geology
*''Hot Stuff to Cold Stone'' – Aitken, Jefley; GNS Science, 1997. . *''Rocked and Ruptured'' – Aitken, Jefley; Reed Books, in association with GNS Science, 1999. . *''The Rise and Fall of the Southern Alps'' – Coates, Glenn; Canterbury University Press, 2002. . *''Plate Tectonics for Curious Kiwis'' – Aitken, Jefley; GNS Science, 1996. . *''Lava and Strata: A guide to the volcanoes and rock formations of Auckland'' – Homer, Lloyd; Moore, Phil & Kermode, Les; Landscape Publications and the Institute of Geological and Nuclear Sciences, 2000. . *''Vanishing volcanoes : a guide to the landforms and rock formations of Coromandel Peninsula'' – Homer, Lloyd; Moore, Phil; Landscape Publications and the Institute of Geological and Nuclear Sciences, 1992. . *''Reading the rocks : a guide to geological features of the Wairarapa Coast'' – Homer, Lloyd; Moore, Phil & Kermode, Les; Landscape Publications and the Institute of Geological and Nuclear Sciences, 1989.


External links



from GNS Science
Geological Society of New ZealandNew Zealand Journal of Geology and Geophysics

A simple geological map of New Zealand
from Te Ara: The Encyclopedia of New Zealand {{Oceania topic, Geology of