Maar

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Maar

A maar is a broad, low-relief

Relief

A relief is a sculptured artwork where a modelled form is raised, or in sunken-relief lowered, from a flatish background plane without being disconnected from it....
volcanic crater

Volcanic crater

A volcanic crater is a circular depression in the ground caused by volcanic activity. It is typically a basin, circular in form within which occurs a vent from which magma erupts as gases, lava, and ejecta....
that is caused by a phreatomagmatic eruption

Phreatomagmatic eruption

Phreatomagmatic eruptions are defined as juvenile forming eruptions as a result of interaction between water and magma. They are different from magmatic and phreatic eruptions....
, an explosion

Explosion

An explosion is a sudden increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases....
caused by groundwater

Groundwater

Groundwater is water located beneath the ground surface in soil porosity spaces and in the fractures of lithologic formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water....
coming into contact with hot lava

Lava

Lava is molten Rock expelled by a volcano during an eruption. When first expelled from a volcanic vent, it is a liquid at temperatures from 700 ?C to 1,200 ?C ....
or magma

Magma

Magma is molten Rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles....
. A maar characteristically fills with water

Water

Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or States of matter, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam....
to form a relatively shallow crater lake

Crater Lake

Crater Lake is a caldera lake located in the U.S. state of Oregon. It is the main feature of Crater Lake National Park and famous for its deep blue color and water clarity....
. The name comes from a local Palatinate German

Palatinate German

Palatine German is a West Franconian dialect of German language which is spoken in the Rhine Valley between the cities of Zweibr?cken, Kaiserslautern, and Mannheim, and the border to the Alsace region and the Rhine River....
dialect

Dialect

A dialect is a variety of a language that is characteristic of a particular group of the language's speakers. The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors, such as social class....
of Daun, which is in turn derived from Latin

Latin

Latin is an Italic language, historically spoken in Latium and Ancient Rome. Through the Military history of the Roman Empire, Latin spread throughout the Mediterranean and a large part of Europe....
mare (sea

SEA

See also: Sea and seasThe three-letter acronym SEA may refer to:People/organizations/businesses*Scientists and Engineers for America, a pro-science political advocacy group....
). Maars are shallow, flat-floored craters that scientist

Scientist

A scientist, in the broadest sense, refers to any person that engages in a system activity to acquire knowledge or an individual that engages in such practices and traditions that are linked to schools of thought or philosophy....
s interpret as having formed above diatreme

Diatreme

A diatreme is a Breccia filled volcanic pipe that was formed by a gaseous explosion. Diatremes often breach the surface and produce a tuff cone or a filled relatively shallow crater known as a maar or other volcanic pipes....
s as a result of a violent expansion of magmatic gas

Gas

In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion....
or steam

Steam

In physical chemistry, and in engineering, steam refers to vaporized water. It is a pure, completely invisible gaseous phase . At standard temperature and pressure, pure steam occupies about 1,600 times the volume of an equal mass of liquid water....
; deep erosion

Erosion

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Encyclopedia

A maar is a broad, low-relief

Relief

A relief is a sculptured artwork where a modelled form is raised, or in sunken-relief lowered, from a flatish background plane without being disconnected from it....
volcanic crater

Volcanic crater

Phreatomagmatic eruption

Phreatomagmatic eruptions are defined as juvenile forming eruptions as a result of interaction between water and magma. They are different from magmatic and phreatic eruptions....
, an explosion

Explosion

An explosion is a sudden increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases....
caused by groundwater

Groundwater

Lava

Lava is molten Rock expelled by a volcano during an eruption. When first expelled from a volcanic vent, it is a liquid at temperatures from 700 ?C to 1,200 ?C ....
or magma

Magma

Water

Crater Lake

Palatinate German

Dialect

Latin

SEA

Scientist

Diatreme

Gas

In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion....
or steam

Steam

Erosion

For morphological image processing operations, see Erosion 'For use of in dermatopathology, see Erosion Erosion is the removal of solids in the natural environment....
of a maar presumably would expose a diatreme. Maars range in size from across and from deep, and most are commonly filled with water to form natural lake

Lake

A lake is a terrain feature , a body of liquid on the surface of a world that is localized to the bottom of basin and moves slowly if it moves at all....
s. Most maars have low rims composed of a mixture of loose fragments of volcanic rock

Volcanic rock

Volcanic rock is an igneous rock of Volcano origin.Texture Volcanic rocks are usually fine-grained or aphanitic to glassy in texture....
s and rocks torn from the walls of the diatreme.

Examples

The largest known maars are found on the Seward Peninsula

Seward Peninsula

The Seward Peninsula is a large peninsula on the western coast of the U.S. state of Alaska. It projects about into the Bering Sea between Norton Sound, the Bering Strait, the Chukchi Sea, and Kotzebue Sound, just below the Arctic Circle....
in northwest Alaska. These maars range in size from 4,000 m (13,100 ft) to 8,000 m (26,200 ft) in diameter and a depth up to 300 m (980 ft). Their large size is due to the explosive reaction that occurs when magma

Magma

Permafrost

In geology, permafrost or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of the ground material....
. Examples of the Seward Peninsula maars include North Killeak Maar, South Killeak Maar, Devil Mountain Maar and Whitefish Maar.

Maars occur in western North America

North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
, Patagonia

Patagonia

Patagonia is a geographic region containing the southernmost portion of South America. Located in Argentina and Chile, it comprises the Andes mountains to the west and south, and plateaux and low plains to the east....
in South America

South America

South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere....
, the Eifel

Eifel

The Eifel is a low mountain range in western Germany. It occupies parts of southwestern North Rhine-Westphalia and northwestern Rhineland-Palatinate....
region of Germany

Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
(where they were originally described), and in other geologically young volcanic regions of Earth

Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
. Kilbourne Hole

Kilbourne Hole

Kilbourne Hole is a maar volcanic crater, located west of the Franklin mountains of El Paso, Texas, in the Potrillo volcanic field of Do?a Ana County, New Mexico....
and Hunt's Hole, near El Paso, Texas

El Paso, Texas

El Paso is a city in and the county seat of El Paso County, Texas, Texas, United States, and part of the . According to the United States Census Bureau 2006 population estimates, the city had a population of 606,913....
, are maars. The notorious, carbon dioxide

Carbon dioxide

Carbon dioxide is a chemical compound composed of two oxygen atoms covalent bond to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state....
-saturated Lake Nyos

Lake Nyos

Lake Nyos is a crater lake in the Northwest Province, Cameroon of Cameroon, located about northwest of Yaound?. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity....
in Africa

Africa

Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km? including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area....
is another example. An excellent example of a maar is Zuni Salt Lake

Zuni Salt Lake

Zuni Salt Lake, also Zu?i Salt Lake or Fence Lake , is a rare high desert lake, and a classic maar. It is located in Catron County, New Mexico, about 60 miles south of the Zuni Pueblo, New Mexico, USA....
in New Mexico

New Mexico

New Mexico is a U. S. State located in the Southwestern United States of the United States. Inhabited by Native Americans in the United States populations for many centuries, it has also has been part of the Spanish Empire viceroyalty of New Spain, part of Mexico, and a U.S....
, a shallow saline lake that occupies a flat-floored crater about across and deep. Its low rim is composed of loose pieces of basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually gray to black and fine-grained due to rapid cooling of lava at the surface of a planet....
ic lava and wallrocks (sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock Particle size . Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust ....
, shale

Shale

Shale is a fine-grained sedimentary rock whose original constituents were clay minerals or muds. It is characterized by thin laminae breaking with an irregular curving fracture, often splintery and usually parallel to the often-indistinguishable bedding plane....
, limestone

Limestone

File:Limestone Formation In Waitomo.jpgLimestone is a sedimentary rock composed largely of the mineral calcite . The deposition of limestone strata is often a by-product and indicator of biological activity in the geology record....
) of the underlying diatreme

Diatreme

A diatreme is a Breccia filled volcanic pipe that was formed by a gaseous explosion. Diatremes often breach the surface and produce a tuff cone or a filled relatively shallow crater known as a maar or other volcanic pipes....
, as well as random chunks of ancient crystalline rocks blasted upward from great depths. Maars in Canada

Canada

Canada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean....
are found in the Wells Gray-Clearwater volcanic field

Wells Gray-Clearwater volcanic field

The Wells Gray-Clearwater volcanic field, also called the Clearwater Cone Group, is a potentially active monogenetic volcanic field in east-central British Columbia, Canada, located approximately north of Kamloops, British Columbia....
of east-central British Columbia

British Columbia

British Columbia is the westernmost of Canada's Provinces and territories of Canada and is famed for its natural beauty, as reflected in its Latin motto, Splendor sine occasu ....
and in kimberlite

Kimberlite

Kimberlite is a type of potassic volcanic rock best known for sometimes containing diamonds. It is named after the town of Kimberley, Northern Cape in South Africa, where the discovery of an diamond in 1871 spawned a diamond rush, eventually creating the Big Hole....
fields throughout Canada. A notable field of maars is found in the Pali Aike Volcanic Field in Patagonia

Patagonia

Arizona

The State of Arizona is a U.S. state located in the Southwestern United States of the United States. The capital and largest city is Phoenix, Arizona....
's Meteor Crater

Meteor Crater

Meteor Crater is a meteorite impact crater located approximately east of Flagstaff, Arizona, near Winslow, Arizona in the northern Arizona desert of the United States....
; for many years this was thought to be of of volcanic rather than meteoric origin.

Maar

Examples

Gallery

External links