document_title: Mount Rushmore

question_text: what is the american indian name for mount rushmore

text: Mount Rushmore

text: History[edit]

text:
Southwestern South Dakota

Sculpture

Mount Rushmore (National Memorial)
Crazy Horse

Geologic formations

Badlands (National Park)
Bear Butte (National Historic Landmark)
Needles
Black Hills
Spearfish Canyon

Mountains

Black Elk Peak
Iron Mountain

Caves

Wind Cave (National Park)
Jewel Cave (National Monument)

Forests and wildernesses

Custer (State Park)
Black Hills (National Forest)
Black Elk (Wilderness)
Buffalo Gap (National Grassland)

Lakes

Sylvan
Pactola

v
t
e

text: Originally known to the Lakota Sioux as "The Six Grandfathers",[11] the mountain was renamed after Charles E. Rushmore, a prominent New York lawyer, during an expedition in 1885.[12] At first, the project of carving Rushmore was undertaken to increase tourism in the Black Hills region of South Dakota. After long negotiations involving a Congressional delegation and President Calvin Coolidge, the project received Congressional approval. The carving started in 1927 and ended in 1941 with no fatalities.[13]

text: As Six Grandfathers, the mountain was part of the route that Lakota leader Black Elk took in a spiritual journey that culminated at Black Elk Peak. Following a series of military campaigns from 1876 to 1878, the United States asserted control over the area, a claim that is still disputed on the basis of the 1868 Treaty of Fort Laramie (see section "Controversy" below). Among American settlers, the peak was known variously as Cougar Mountain, Sugarloaf Mountain, Slaughterhouse Mountain, and Keystone Cliffs. It was named Mount Rushmore during a prospecting expedition by Charles Rushmore, David Swanzey (husband of Carrie Ingalls), and Bill Challis.[14]

text: Historian Doane Robinson conceived the idea for Mount Rushmore in 1923 to promote tourism in South Dakota. In 1924, Robinson persuaded sculptor Gutzon Borglum to travel to the Black Hills region to ensure the carving could be accomplished. Borglum had been involved in sculpting the Confederate Memorial Carving, a massive bas-relief memorial to Confederate leaders on Stone Mountain in Georgia, but was in disagreement with the officials there.[15]

text: The original plan was to make the carvings in granite pillars known as the Needles. However, Borglum realized that the eroded Needles were too thin to support sculpting. He chose Mount Rushmore, a grander location, partly because it faced southeast and enjoyed maximum exposure to the sun. Borglum said upon seeing Mount Rushmore, "America will march along that skyline."[16] Congress authorized the Mount Rushmore National Memorial Commission on March 3, 1925.[16]

text: Between October 4, 1927, and October 31, 1941, Gutzon Borglum and 400 workers[17] sculpted the colossal 60 foot (18 m) high carvings of U.S. presidents George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln to represent the first 130 years of American history. These presidents were selected by Borglum because of their role in preserving the Republic and expanding its territory.[16][18] The carving of Mount Rushmore involved the use of dynamite, followed by the process of "honeycombing", a process where workers drill holes close together, allowing small pieces to be removed by hand.[19] In total, about 450,000 short tons (410,000 t) of rock were blasted off the mountainside.[20] The image of Thomas Jefferson was originally intended to appear in the area at Washington's right, but after the work there was begun, the rock was found to be unsuitable, so the work on the Jefferson figure was dynamited, and a new figure was sculpted to Washington's left.[16]

text: The Chief Carver of the mountain was Luigi del Bianco, artisan and headstone carver in Port Chester, NY. Del Bianco emigrated to the U.S. from Friuli in Italy, and was chosen to work on this project because of his remarkable skill at etching emotions and personality into his carved portraits.[2][3]

text: In 1933, the National Park Service took Mount Rushmore under its jurisdiction. Julian Spotts helped with the project by improving its infrastructure. For example, he had the tram upgraded so it could reach the top of Mount Rushmore for the ease of workers. By July 4, 1934, Washington's face had been completed and was dedicated. The face of Thomas Jefferson was dedicated in 1936, and the face of Abraham Lincoln was dedicated on September 17, 1937. In 1937, a bill was introduced in Congress to add the head of civil-rights leader Susan B. Anthony, but a rider was passed on an appropriations bill requiring federal funds be used to finish only those heads that had already been started at that time.[21] In 1939, the face of Theodore Roosevelt was dedicated.

text: The Sculptor's Studio – a display of unique plaster models and tools related to the sculpting – was built in 1939 under the direction of Borglum. Borglum had planned to make a secret room behind the hairline of Abraham Lincoln which was supposed to be a doorway to a chamber originally intended to hold some of America's most treasured documents but was left unfinished due to his death.[22] Borglum died from an embolism in March 1941. His son, Lincoln Borglum, continued the project. Originally, it was planned that the figures would be carved from head to waist,[23] but insufficient funding forced the carving to end. Borglum had also planned a massive panel in the shape of the Louisiana Purchase commemorating in eight-foot-tall gilded letters the Declaration of Independence, U.S. Constitution, Louisiana Purchase, and seven other territorial acquisitions from Alaska to Texas to the Panama Canal Zone.[18] In total, the entire project cost US$989,992.32.[24] Unusually for a project of such size, no workers died during the carving.[25]

text: On October 15, 1966, Mount Rushmore was listed on the National Register of Historic Places. A 500-word essay giving the history of the United States by Nebraska student William Andrew Burkett was selected as the college-age group winner in a 1934 competition, and that essay was placed on the Entablature on a bronze plate in 1973.[21][26] In 1991, President George H. W. Bush officially dedicated Mount Rushmore.[27]

text: In a canyon behind the carved faces is a chamber, cut only 70 feet (21 m) into the rock, containing a vault with sixteen porcelain enamel panels. The panels include the text of the Declaration of Independence and the Constitution, biographies of the four presidents and Borglum, and the history of the U.S. The chamber was created as the entrance-way to a planned "Hall of Records"; the vault was installed in 1998.[28]

text: Ten years of redevelopment work culminated with the completion of extensive visitor facilities and sidewalks in 1998, such as a Visitor Center, the Lincoln Borglum Museum, and the Presidential Trail. Maintenance of the memorial requires mountain climbers to monitor and seal cracks annually. Due to budget constraints, the memorial is not regularly cleaned to remove lichens. However, on July 8, 2005, Alfred Kärcher GmbH, a German manufacturer of pressure washing and steam cleaning machines, conducted a free cleanup operation which lasted several weeks, using pressurized water at over 200 °F (93 °C).[29]

text: Ecology[edit]

text: The flora and fauna of Mount Rushmore are similar to those of the rest of the Black Hills region of South Dakota. Birds including the turkey vulture, bald eagle, hawk, and meadowlark fly around Mount Rushmore, occasionally making nesting spots in the ledges of the mountain. Smaller birds, including songbirds, nuthatches, and woodpeckers, inhabit the surrounding pine forests.[30] Terrestrial mammals include the mouse, least chipmunk, red squirrel, skunk, porcupine, raccoon, beaver, badger, coyote, bighorn sheep, bobcat, elk, mule deer, yellow-bellied marmot, and American bison.[30][31] The striped chorus frog, western chorus frog, and northern leopard frog also inhabit the area,[32] along with several species of snake. Grizzly Bear Brook and Starling Basin Brook, the two streams in the memorial, support fish such as the longnose dace and the brook trout.[citation needed] Mountain goats are not indigenous to the region. Those living near Mount Rushmore are descendents of a tribe that Canada gifted to Custer State Park in 1924, which later escaped.[30][33][34]

text: At lower elevations, coniferous trees, mainly the ponderosa pine, surround most of the monument, providing shade from the sun. Other trees include the bur oak, the Black Hills spruce, and the cottonwood. Nine species of shrubs grow near Mount Rushmore. There is also a wide variety of wildflowers, including especially the snapdragon, sunflower, and violet. Towards higher elevations, plant life becomes sparser.[34] However, only approximately five percent of the plant species found in the Black Hills are indigenous to the region.[35]

text: The area receives about 18 inches (460 mm) of precipitation on average per year, enough to support abundant animal and plant life. Trees and other plants help to control surface runoff. Dikes, seeps, and springs help to dam up water that is flowing downhill, providing watering spots for animals. In addition, stones like sandstone and limestone help to hold groundwater, creating aquifers.[36]

text: A study of the fire scars present in tree ring samples indicates that forest fires occur in the ponderosa forests surrounding Mount Rushmore around every 27 years. Large fires are not common. Most events have been ground fires that serve to clear forest debris.[37] The area is a climax community. Recent[when?] pine beetle infestations have threatened the forest.[31]

text: Geography[edit]

text: Geology[edit]

text: Mount Rushmore is largely composed of granite. The memorial is carved on the northwest margin of the Black Elk Peak granite batholith in the Black Hills of South Dakota, so the geologic formations of the heart of the Black Hills region are also evident at Mount Rushmore. The batholith magma intruded into the pre-existing mica schist rocks during the Proterozoic, 1.6 billion years ago.[38] Coarse grained pegmatite dikes are associated with the granite intrusion of Black Elk Peak and are visibly lighter in color, thus explaining the light-colored streaks on the foreheads of the presidents.

text: The Black Hills granites were exposed to erosion during the Neoproterozoic, but were later buried by sandstone and other sediments during the Cambrian. Remaining buried throughout the Paleozoic, they were re-exposed again during the Laramide orogeny around 70 million years ago.[38] The Black Hills area was uplifted as an elongated geologic dome.[39] Subsequent erosion stripped the granite of the overlying sediments and the softer adjacent schist. Some schist does remain and can be seen as the darker material just below the sculpture of Washington.

text: The tallest mountain in the region is Black Elk Peak (7,242 ft or 2,207 m). Borglum selected Mount Rushmore as the site for several reasons. The rock of the mountain is composed of smooth, fine-grained granite. The durable granite erodes only 1 inch (25 mm) every 10,000 years, thus was more than sturdy enough to support the sculpture and its long-term exposure.[16] The mountain's height of 5,725 feet (1,745 m) above sea level[6] made it suitable, and because it faces the southeast, the workers also had the advantage of sunlight for most of the day.

text: Soils[edit]

text: The Mount Rushmore area is underlain by well drained alfisol soils of very gravelly loam (Mocmount) to silt loam (Buska) texture, brown to dark grayish brown.[40]

text: Climate[edit]

text: Mount Rushmore has a humid continental climate (Dwb in the Köppen climate classification). It is inside a USDA Plant Hardiness Zone of 5a, meaning certain plant life in the area can withstand a low temperature of no less than −20 °F (−29 °C).[41]

text: The two wettest months of the year are May and June. Orographic lift causes brief but strong afternoon thunderstorms during the summer.[42]

text:
[hide]Climate data for Mount Rushmore National Memorial, 1981-2011 normals

Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year

Record high °F (°C)
68
(20)
68
(20)
78
(26)
85
(29)
93
(34)
99
(37)
100
(38)
99
(37)
97
(36)
86
(30)
75
(24)
67
(19)
100
(38)

Average high °F (°C)
36.3
(2.4)
36.7
(2.6)
43.2
(6.2)
50.7
(10.4)
60.7
(15.9)
71.0
(21.7)
79.1
(26.2)
78.1
(25.6)
67.8
(19.9)
54.9
(12.7)
42.9
(6.1)
35.3
(1.8)
54.7
(12.6)

Daily mean °F (°C)
27.5
(−2.5)
27.8
(−2.3)
33.9
(1.1)
41.4
(5.2)
51.1
(10.6)
61.1
(16.2)
69.0
(20.6)
67.9
(19.9)
58.0
(14.4)
45.7
(7.6)
34.5
(1.4)
26.7
(−2.9)
45.4
(7.4)

Average low °F (°C)
18.7
(−7.4)
19.0
(−7.2)
24.6
(−4.1)
32.0
(0)
41.6
(5.3)
51.3
(10.7)
58.9
(14.9)
57.7
(14.3)
48.2
(9)
36.5
(2.5)
26.0
(−3.3)
18.1
(−7.7)
36.0
(2.2)

Record low °F (°C)
−38
(−39)
−29
(−34)
−12
(−24)
1
(−17)
14
(−10)
27
(−3)
35
(2)
33
(1)
19
(−7)
1
(−17)
−12
(−24)
−31
(−35)
−38
(−39)

Average precipitation inches (mm)
0.38
(9.7)
0.70
(17.8)
1.19
(30.2)
2.23
(56.6)
4.22
(107.2)
3.41
(86.6)
2.90
(73.7)
1.99
(50.5)
1.81
(46)
1.68
(42.7)
0.62
(15.7)
0.43
(10.9)
21.56
(547.6)

Average snowfall inches (cm)
5.8
(14.7)
7.9
(20.1)
10.4
(26.4)
10.8
(27.4)
1.2
(3)
0.1
(0.3)
0.0
(0)
0.0
(0)
0.6
(1.5)
3.6
(9.1)
6.2
(15.7)
5.8
(14.7)
52.4
(132.9)

Average precipitation days (≥ 0.01)
4.3
4.7
6.3
8.2
11.9
12.6
11.4
9.3
7.4
6.8
4.4
4.2
91.5

Average snowy days (≥ 0.1)
3.9
3.8
3.9
3.1
0.6
0.0
0.0
0.0
0.3
1.4
2.7
3.4
23.1

Source #1: [43]

Source #2: [44]

text: Tourism[edit]

text:
Historical visitor count[1]

Year
Visitors

1941
393,000

1950
740,499

1960
1,067,000

1970
1,965,700

1980
1,284,888

1990
1,671,673

2000
1,868,876

2010
2,331,237

text: Tourism is South Dakota's second-largest industry, and Mount Rushmore is the state's top tourist attraction.[45] In 2012, 2,185,447 people visited the park.[1] In the 1950s and 1960s, Sioux Benjamin Black Elk (son of medicine man Black Elk) was the "Fifth Face of Mount Rushmore", posing for photographs with thousands of tourists. He became one of the most photographed people in the world.[46]

text: Conservation[edit]

text: The ongoing conservation of the site is overseen by the US National Park Service.[47] Physical efforts to conserve the monument have included replacement of the sealant applied originally by Gutzon Borglum, which had proved ineffective at providing water resistance (components include linseed oil, granite dust and white lead). A modern silicone replacement was used, disguised with granite dust.

text: In 1998, electronic monitoring devices were installed to track movement in the topology of the sculpture to an accuracy of 3 mm. The site has been subsequently digitally recorded using a terrestrial laser scanning methodology in 2009 as part of the international Scottish Ten project, providing a record of unprecedented resolution and accuracy to inform the conservation of the site. This data was made accessible online to be freely used by the wider community to aid further interpretation and public access.[48]

text: Controversy[edit]

text: The United States seized the area from the Lakota tribe after the Great Sioux War of 1876. The Treaty of Fort Laramie from 1868 had previously granted the Black Hills to the Lakota in perpetuity. Members of the American Indian Movement led an occupation of the monument in 1971, naming it "Mount Crazy Horse". Among the participants were young activists, grandparents, children and Lakota holy man John Fire Lame Deer, who planted a prayer staff atop the mountain. Lame Deer said the staff formed a symbolic shroud over the presidents' faces "which shall remain dirty until the treaties concerning the Black Hills are fulfilled."[49]

text: In 2004, the first Native American superintendent of the park, Gerard Baker, was appointed. Baker has stated that he will open up more "avenues of interpretation", and that the four presidents are "only one avenue and only one focus."[50]

text: The Crazy Horse Memorial is being constructed elsewhere in the Black Hills to commemorate the famous Native American leader as a response to Mount Rushmore. It is said to be larger than Mount Rushmore and has the support of Lakota chiefs; the Crazy Horse Memorial Foundation has rejected offers of federal funds. However, this memorial is likewise the subject of controversy, even within the Native American community.[51]

text: In popular culture[edit]

text: Because of its fame as a monument, Mount Rushmore has been depicted in multiple places in popular culture. It is often depicted as a cover for a secret location; shown with faces removed or modified (as in Superman II), or added; or parodied. Trey Parker and Matt Stone used the location as the headquarters for their movie Team America: World Police. The memorial was also famously used as the location of the climactic chase scene in Alfred Hitchcock's 1959 movie North by Northwest.[52]

text: Legacy and commemoration[edit]

text: On August 11, 1952, the U.S. Post Office issued the Mount Rushmore Memorial commemorative stamp on the 25th anniversary of the dedication of the Mt. Rushmore National Memorial in the Black Hills of South Dakota.[53] On January 2, 1974, a 26-cent airmail stamp depicting the monument was also issued.[54]


document_title: Igneous rock

question_text: what is an example of an intrusive igneous rock

root

text: Igneous rock

text: Geological significance

text: Igneous and metamorphic rocks make up 90–95% of the top 16 km of the Earth's crust by volume.[1] Igneous rocks form about 15% of the Earth's current land surface.[note 1] Most of the Earth's oceanic crust is made of igneous rock.

tag: p

text: Igneous rocks are also geologically important because:

text:
their minerals and global chemistry give information about the composition of the mantle, from which some igneous rocks are extracted, and the temperature and pressure conditions that allowed this extraction, and/or of other pre-existing rock that melted;
their absolute ages can be obtained from various forms of radiometric dating and thus can be compared to adjacent geological strata, allowing a time sequence of events;
their features are usually characteristic of a specific tectonic environment, allowing tectonic reconstitutions (see plate tectonics);
in some special circumstances they host important mineral deposits (ores): for example, tungsten, tin, and uranium are commonly associated with granites and diorites, whereas ores of chromium and platinum are commonly associated with gabbros.

tag: ul

text: Geological setting

text: In terms of modes of occurrence, igneous rocks can be either intrusive (plutonic and hypabyssal) or extrusive (volcanic).

text: Intrusive

text: Intrusive igneous rocks are formed from magma that cools and solidifies within the crust of a planet, surrounded by pre-existing rock (called country rock); the magma cools slowly and, as a result, these rocks are coarse-grained. The mineral grains in such rocks can generally be identified with the naked eye. Intrusive rocks can also be classified according to the shape and size of the intrusive body and its relation to the other formations into which it intrudes. Typical intrusive formations are batholiths, stocks, laccoliths, sills and dikes. When the magma solidifies within the earth's crust, it cools slowly forming coarse textured rocks, such as granite, gabbro, or diorite.

text: The central cores of major mountain ranges consist of intrusive igneous rocks, usually granite. When exposed by erosion, these cores (called batholiths) may occupy huge areas of the Earth's surface.

text: Intrusive igneous rocks that form at depth within the crust are termed plutonic (or abyssal) rocks and are usually coarse-grained. Intrusive igneous rocks that form near the surface are termed subvolcanic or hypabyssal rocks and they are usually medium-grained. Hypabyssal rocks are less common than plutonic or volcanic rocks and often form dikes, sills, laccoliths, lopoliths, or phacoliths.

text: Extrusive

text: Extrusive igneous rocks, also known as volcanic rocks, are formed at the crust's surface as a result of the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate. Hence such rocks are smooth, crystalline and fine-grained. Basalt is a common extrusive igneous rock and forms lava flows, lava sheets and lava plateaus. Some kinds of basalt solidify to form long polygonal columns. The Giant's Causeway in Antrim, Northern Ireland is an example.

text: The molten rock, with or without suspended crystals and gas bubbles, is called magma. It rises because it is less dense than the rock from which it was created. When magma reaches the surface from beneath water or air, it is called lava. Eruptions of volcanoes into air are termed subaerial, whereas those occurring underneath the ocean are termed submarine. Black smokers and mid-ocean ridge basalt are examples of submarine volcanic activity.

text: The volume of extrusive rock erupted annually by volcanoes varies with plate tectonic setting. Extrusive rock is produced in the following proportions:[3]

text:
divergent boundary: 73%
convergent boundary (subduction zone): 15%
hotspot: 12%.

text: Magma that erupts from a volcano behaves according to its viscosity, determined by temperature, composition, crystal content and the amount of silica. High-temperature magma, most of which is basaltic in composition, behaves in a manner similar to thick oil and, as it cools, treacle. Long, thin basalt flows with pahoehoe surfaces are common. Intermediate composition magma, such as andesite, tends to form cinder cones of intermingled ash, tuff and lava, and may have a viscosity similar to thick, cold molasses or even rubber when erupted. Felsic magma, such as rhyolite, is usually erupted at low temperature and is up to 10,000 times as viscous as basalt. Volcanoes with rhyolitic magma commonly erupt explosively, and rhyolitic lava flows are typically of limited extent and have steep margins, because the magma is so viscous.

text: Felsic and intermediate magmas that erupt often do so violently, with explosions driven by the release of dissolved gases—typically water vapour, but also carbon dioxide. Explosively erupted pyroclastic material is called tephra and includes tuff, agglomerate and ignimbrite. Fine volcanic ash is also erupted and forms ash tuff deposits, which can often cover vast areas.

text: Because lava usually cools and crystallizes rapidly, it is usually fine-grained. If the cooling has been so rapid as to prevent the formation of even small crystals after extrusion, the resulting rock may be mostly glass (such as the rock obsidian). If the cooling of the lava happened more slowly, the rock would be coarse-grained.

text: Because the minerals are mostly fine-grained, it is much more difficult to distinguish between the different types of extrusive igneous rocks than between different types of intrusive igneous rocks. Generally, the mineral constituents of fine-grained extrusive igneous rocks can only be determined by examination of thin sections of the rock under a microscope, so only an approximate classification can usually be made in the field.

text: Classification

text: Igneous rocks are classified according to mode of occurrence, texture, mineralogy, chemical composition, and the geometry of the igneous body.

text: The classification of the many types of different igneous rocks can provide us with important information about the conditions under which they formed. Two important variables used for the classification of igneous rocks are particle size, which largely depends on the cooling history, and the mineral composition of the rock. Feldspars, quartz or feldspathoids, olivines, pyroxenes, amphiboles, and micas are all important minerals in the formation of almost all igneous rocks, and they are basic to the classification of these rocks. All other minerals present are regarded as nonessential in almost all igneous rocks and are called accessory minerals. Types of igneous rocks with other essential minerals are very rare, and these rare rocks include those with essential carbonates.

text: In a simplified classification, igneous rock types are separated on the basis of the type of feldspar present, the presence or absence of quartz, and in rocks with no feldspar or quartz, the type of iron or magnesium minerals present. Rocks containing quartz (silica in composition) are silica-oversaturated. Rocks with feldspathoids are silica-undersaturated, because feldspathoids cannot coexist in a stable association with quartz.

text: Igneous rocks that have crystals large enough to be seen by the naked eye are called phaneritic; those with crystals too small to be seen are called aphanitic. Generally speaking, phaneritic implies an intrusive origin; aphanitic an extrusive one.

text: An igneous rock with larger, clearly discernible crystals embedded in a finer-grained matrix is termed porphyry. Porphyritic texture develops when some of the crystals grow to considerable size before the main mass of the magma crystallizes as finer-grained, uniform material.

text: Igneous rocks are classified on the basis of texture and composition. Texture refers to the size, shape, and arrangement of the mineral grains or crystals of which the rock is composed.

text: Texture

text: Texture is an important criterion for the naming of volcanic rocks. The texture of volcanic rocks, including the size, shape, orientation, and distribution of mineral grains and the intergrain relationships, will determine whether the rock is termed a tuff, a pyroclastic lava or a simple lava.

text: However, the texture is only a subordinate part of classifying volcanic rocks, as most often there needs to be chemical information gleaned from rocks with extremely fine-grained groundmass or from airfall tuffs, which may be formed from volcanic ash.

text: Textural criteria are less critical in classifying intrusive rocks where the majority of minerals will be visible to the naked eye or at least using a hand lens, magnifying glass or microscope. Plutonic rocks also tend to be less texturally varied and less prone to gaining structural fabrics. Textural terms can be used to differentiate different intrusive phases of large plutons, for instance porphyritic margins to large intrusive bodies, porphyry stocks and subvolcanic dikes (apophyses). Mineralogical classification is most often used to classify plutonic rocks. Chemical classifications are preferred to classify volcanic rocks, with phenocryst species used as a prefix, e.g. "olivine-bearing picrite" or "orthoclase-phyric rhyolite".

text: see also List of rock textures and Igneous textures

text: Chemical classification and petrology

text: Igneous rocks can be classified according to chemical or mineralogical parameters.

text: Chemical: total alkali-silica content (TAS diagram) for volcanic rock classification used when modal or mineralogic data is unavailable:

text:
felsic igneous rocks containing a high silica content, greater than 63% SiO2 (examples granite and rhyolite),
intermediate igneous rocks containing between 52–63% SiO2 (example andesite and dacite),
mafic igneous rocks have low silica 45–52% and typically high iron – magnesium content (example gabbro and basalt),
ultramafic rock igneous rocks with less than 45% silica (examples picrite, komatiite and peridotite),
alkalic igneous rocks with 5–15% alkali (K2O + Na2O) content or with a molar ratio of alkali to silica greater than 1:6 (examples phonolite and trachyte).

text: Chemical classification also extends to differentiating rocks that are chemically similar according to the TAS diagram, for instance:

text:
Ultrapotassic – rocks containing molar K2O/Na2O >3.
Peralkaline – rocks containing molar (K2O + Na2O)/Al2O3 >1.
Peraluminous – rocks containing molar (K2O + Na2O)/Al2O3 <1.

text: An idealized mineralogy (the normative mineralogy) can be calculated from the chemical composition, and the calculation is useful for rocks too fine-grained or too altered for identification of minerals that crystallized from the melt. For instance, normative quartz classifies a rock as silica-oversaturated; an example is rhyolite. In an older terminology, silica oversaturated rocks were called silicic or acidic where the SiO2 was greater than 66% and the family term quartzolite was applied to the most silicic. A normative feldspathoid classifies a rock as silica-undersaturated; an example is nephelinite.

text: History of classification

text: In 1902, a group of American petrographers proposed that all existing classifications of igneous rocks should be discarded and replaced by a "quantitative" classification based on chemical analysis. They showed how vague, and often unscientific, much of the existing terminology was and argued that as the chemical composition of an igneous rock was its most fundamental characteristic, it should be elevated to prime position.

text: Geological occurrence, structure, mineralogical constitution—the hitherto accepted criteria for the discrimination of rock species—were relegated to the background. The completed rock analysis is first to be interpreted in terms of the rock-forming minerals which might be expected to be formed when the magma crystallizes, e.g., quartz feldspars, olivine, akermannite, Feldspathoids, magnetite, corundum, and so on, and the rocks are divided into groups strictly according to the relative proportion of these minerals to one another.[5][6]

text: Mineralogical classification

text: For volcanic rocks, mineralogy is important in classifying and naming lavas. The most important criterion is the phenocryst species, followed by the groundmass mineralogy. Often, where the groundmass is aphanitic, chemical classification must be used to properly identify a volcanic rock.

text: Mineralogic contents – felsic versus mafic

text:
felsic rock, highest content of silicon, with predominance of quartz, alkali feldspar and/or feldspathoids: the felsic minerals; these rocks (e.g., granite, rhyolite) are usually light coloured, and have low density.
mafic rock, lesser content of silicon relative to felsic rocks, with predominance of mafic minerals pyroxenes, olivines and calcic plagioclase; these rocks (example, basalt, gabbro) are usually dark coloured, and have a higher density than felsic rocks.
ultramafic rock, lowest content of silicon, with more than 90% of mafic minerals (e.g., dunite).

text: For intrusive, plutonic and usually phaneritic igneous rocks (where all minerals are visible at least via microscope), the mineralogy is used to classify the rock. This usually occurs on ternary diagrams, where the relative proportions of three minerals are used to classify the rock.

text: The following table is a simple subdivision of igneous rocks according to both their composition and mode of occurrence.

text:
Composition

Mode of occurrence
Felsic
Intermediate
Mafic
Ultramafic

Intrusive
Granite
Diorite
Gabbro
Peridotite

Extrusive
Rhyolite
Andesite
Basalt
Komatiite

tag: table

text: For a more detailed classification see QAPF diagram.

text: Example of classification

text: Granite is an igneous intrusive rock (crystallized at depth), with felsic composition (rich in silica and predominately quartz plus potassium-rich feldspar plus sodium-rich plagioclase) and phaneritic, subeuhedral texture (minerals are visible to the unaided eye and commonly some of them retain original crystallographic shapes).

text: Magma origination

text: The Earth's crust averages about 35 kilometers thick under the continents, but averages only some 7–10 kilometers beneath the oceans. The continental crust is composed primarily of sedimentary rocks resting on a crystalline basement formed of a great variety of metamorphic and igneous rocks, including granulite and granite. Oceanic crust is composed primarily of basalt and gabbro. Both continental and oceanic crust rest on peridotite of the mantle.

text: Rocks may melt in response to a decrease in pressure, to a change in composition (such as an addition of water), to an increase in temperature, or to a combination of these processes.

text: Other mechanisms, such as melting from a meteorite impact, are less important today, but impacts during the accretion of the Earth led to extensive melting, and the outer several hundred kilometers of our early Earth was probably an ocean of magma. Impacts of large meteorites in the last few hundred million years have been proposed as one mechanism responsible for the extensive basalt magmatism of several large igneous provinces.

text: Decompression

text: Decompression melting occurs because of a decrease in pressure.[7]

text: The solidus temperatures of most rocks (the temperatures below which they are completely solid) increase with increasing pressure in the absence of water. Peridotite at depth in the Earth's mantle may be hotter than its solidus temperature at some shallower level. If such rock rises during the convection of solid mantle, it will cool slightly as it expands in an adiabatic process, but the cooling is only about 0.3 °C per kilometer. Experimental studies of appropriate peridotite samples document that the solidus temperatures increase by 3 °C to 4 °C per kilometer. If the rock rises far enough, it will begin to melt. Melt droplets can coalesce into larger volumes and be intruded upwards. This process of melting from the upward movement of solid mantle is critical in the evolution of the Earth.

text: Decompression melting creates the ocean crust at mid-ocean ridges. It also causes volcanism in intraplate regions, such as Europe, Africa and the Pacific sea floor. There, it is variously attributed either to the rise of mantle plumes (the "Plume hypothesis") or to intraplate extension (the "Plate hypothesis").[8]

text: Effects of water and carbon dioxide

text: The change of rock composition most responsible for the creation of magma is the addition of water. Water lowers the solidus temperature of rocks at a given pressure. For example, at a depth of about 100 kilometers, peridotite begins to melt near 800 °C in the presence of excess water, but near or above about 1,500 °C in the absence of water.[9] Water is driven out of the oceanic lithosphere in subduction zones, and it causes melting in the overlying mantle. Hydrous magmas composed of basalt and andesite are produced directly and indirectly as results of dehydration during the subduction process. Such magmas, and those derived from them, build up island arcs such as those in the Pacific Ring of Fire. These magmas form rocks of the calc-alkaline series, an important part of the continental crust.

text: The addition of carbon dioxide is relatively a much less important cause of magma formation than the addition of water, but genesis of some silica-undersaturated magmas has been attributed to the dominance of carbon dioxide over water in their mantle source regions. In the presence of carbon dioxide, experiments document that the peridotite solidus temperature decreases by about 200 °C in a narrow pressure interval at pressures corresponding to a depth of about 70 km. At greater depths, carbon dioxide can have more effect: at depths to about 200 km, the temperatures of initial melting of a carbonated peridotite composition were determined to be 450 °C to 600 °C lower than for the same composition with no carbon dioxide.[10] Magmas of rock types such as nephelinite, carbonatite, and kimberlite are among those that may be generated following an influx of carbon dioxide into mantle at depths greater than about 70 km.

text: Temperature increase

text: Increase in temperature is the most typical mechanism for formation of magma within continental crust. Such temperature increases can occur because of the upward intrusion of magma from the mantle. Temperatures can also exceed the solidus of a crustal rock in continental crust thickened by compression at a plate boundary. The plate boundary between the Indian and Asian continental masses provides a well-studied example, as the Tibetan Plateau just north of the boundary has crust about 80 kilometers thick, roughly twice the thickness of normal continental crust. Studies of electrical resistivity deduced from magnetotelluric data have detected a layer that appears to contain silicate melt and that stretches for at least 1,000 kilometers within the middle crust along the southern margin of the Tibetan Plateau.[11] Granite and rhyolite are types of igneous rock commonly interpreted as products of the melting of continental crust because of increases in temperature. Temperature increases also may contribute to the melting of lithosphere dragged down in a subduction zone.

text: Magma evolution

text: Most magmas only entirely melt for small parts of their histories. More typically, they are mixes of melt and crystals, and sometimes also of gas bubbles. Melt, crystals, and bubbles usually have different densities, and so they can separate as magmas evolve.

text: As magma cools, minerals typically crystallize from the melt at different temperatures (fractional crystallization). As minerals crystallize, the composition of the residual melt typically changes. If crystals separate from the melt, then the residual melt will differ in composition from the parent magma. For instance, a magma of gabbroic composition can produce a residual melt of granitic composition if early formed crystals are separated from the magma. Gabbro may have a liquidus temperature near 1,200 °C, and the derivative granite-composition melt may have a liquidus temperature as low as about 700 °C. Incompatible elements are concentrated in the last residues of magma during fractional crystallization and in the first melts produced during partial melting: either process can form the magma that crystallizes to pegmatite, a rock type commonly enriched in incompatible elements. Bowen's reaction series is important for understanding the idealised sequence of fractional crystallisation of a magma.

text: Magma composition can be determined by processes other than partial melting and fractional crystallization. For instance, magmas commonly interact with rocks they intrude, both by melting those rocks and by reacting with them. Magmas of different compositions can mix with one another. In rare cases, melts can separate into two immiscible melts of contrasting compositions.

text: There are relatively few minerals that are important in the formation of common igneous rocks, because the magma from which the minerals crystallize is rich in only certain elements: silicon, oxygen, aluminium, sodium, potassium, calcium, iron, and magnesium. These are the elements that combine to form the silicate minerals, which account for over ninety percent of all igneous rocks. The chemistry of igneous rocks is expressed differently for major and minor elements and for trace elements. Contents of major and minor elements are conventionally expressed as weight percent oxides (e.g., 51% SiO2, and 1.50% TiO2). Abundances of trace elements are conventionally expressed as parts per million by weight (e.g., 420 ppm Ni, and 5.1 ppm Sm). The term "trace element" is typically used for elements present in most rocks at abundances less than 100 ppm or so, but some trace elements may be present in some rocks at abundances exceeding 1,000 ppm. The diversity of rock compositions has been defined by a huge mass of analytical data—over 230,000 rock analyses can be accessed on the web through a site sponsored by the U. S. National Science Foundation (see the External Link to EarthChem).

text: Etymology

text: The word "igneous" is derived from the Latin ignis, meaning "of fire". Volcanic rocks are named after Vulcan, the Roman name for the god of fire. Intrusive rocks are also called "plutonic" rocks, named after Pluto, the Roman god of the underworld.


document_title: Swim bladder

question_text: where is the swim bladder located in a fish

text: Swim bladder

text: Structure and function[edit]

text: The swim bladder normally consists of two gas-filled sacs located in the dorsal portion of the fish, although in a few primitive species, there is only a single sac. It has flexible walls that contract or expand according to the ambient pressure. The walls of the bladder contain very few blood vessels and are lined with guanine crystals, which make them impermeable to gases. By adjusting the gas pressurising organ using the gas gland or oval window the fish can obtain neutral buoyancy and ascend and descend to a large range of depths. Due to the dorsal position it gives the fish lateral stability.

text: In physostomous swim bladders, a connection is retained between the swim bladder and the gut, the pneumatic duct, allowing the fish to fill up the swim bladder by "gulping" air. Excess gas can be removed in a similar manner.

text: In more derived varieties of fish (the physoclisti) the connection to the digestive tract is lost. In early life stages, these fish must rise to the surface to fill up their swim bladders; in later stages, the pneumatic duct disappears, and the gas gland has to introduce gas (usually oxygen) to the bladder to increase its volume and thus increase buoyancy. In order to introduce gas into the bladder, the gas gland excretes lactic acid and produces carbon dioxide. The resulting acidity causes the hemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. The blood flowing back to the body first enters a rete mirabile where virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea fish like the eel, requiring a pressure of hundreds of bars.[5] Elsewhere, at a similar structure known as the oval window, the bladder is in contact with blood and the oxygen can diffuse back out again. Together with oxygen, other gases are salted out[clarification needed] in the swim bladder which accounts for the high pressures of other gases as well.[6]

text: The combination of gases in the bladder varies. In shallow water fish, the ratios closely approximate that of the atmosphere, while deep sea fish tend to have higher percentages of oxygen. For instance, the eel Synaphobranchus has been observed to have 75.1% oxygen, 20.5% nitrogen, 3.1% carbon dioxide, and 0.4% argon in its swim bladder.

text: Physoclist swim bladders have one important disadvantage: they prohibit fast rising, as the bladder would burst. Physostomes can "burp" out gas, though this complicates the process of re-submergence.

text: The swim bladder in some species, mainly fresh water fishes (Common carp, catfish, bowfin) is interconnected with the inner ear of the fish. They are connected by four bones called the Weberian ossicles from the Weberian apparatus. These bones can carry the vibrations to the Saccule and the Lagena (anatomy). They are suited for detecting sound and vibrations due to its low density in comparison to the density of the fish's body tissues. This increases the ability of sound detection.[7] The swim bladder can radiate the pressure of sound which help increase its sensitivity and expand its hearing. In some deep sea fishes like the Antimora, the swim bladder maybe also connected to the Macula of saccule in order for the inner ear to receive a sensation from the sound pressure.[8] In red-bellied piranha, the swimbladder may play an important role in sound production as a resonator. The sounds created by piranhas are generated through rapid contractions of the sonic muscles and is associated with the swimbladder.[9]

text: Evolution[edit]

text:
The illustration of the swim bladder in fishes ... shows us clearly the highly important fact that an organ originally constructed for one purpose, namely, flotation, may be converted into one for a widely different purpose, namely, respiration. The swim bladder has, also, been worked in as an accessory to the auditory organs of certain fishes. All physiologists admit that the swimbladder is homologous, or “ideally similar” in position and structure with the lungs of the higher vertebrate animals: hence there is no reason to doubt that the swim bladder has actually been converted into lungs, or an organ used exclusively for respiration. According to this view it may be inferred that all vertebrate animals with true lungs are descended by ordinary generation from an ancient and unknown prototype, which was furnished with a floating apparatus or swim bladder.

Charles Darwin, 1859[3]

tag: div

text: Swim bladders are evolutionarily closely related (i.e., homologous) to lungs. Traditional wisdom has long held that the first lungs, simple sacs connected to the gut that allowed the organism to gulp air under oxygen-poor conditions, evolved into the lungs of today's terrestrial vertebrates and some fish (e.g., lungfish, gar, and bichir) and into the swim bladders of the ray-finned fish. In 1997, Farmer proposed that lungs evolved to supply the heart with oxygen. In fish, blood circulates from the gills to the skeletal muscle, and only then to the heart. During intense exercise, the oxygen in the blood gets used by the skeletal muscle before the blood reaches the heart. Primitive lungs gave an advantage by supplying the heart with oxygenated blood via the cardiac shunt. This theory is robustly supported by the fossil record, the ecology of extant air-breathing fishes, and the physiology of extant fishes.[10] In embryonal development, both lung and swim bladder originate as an outpocketing from the gut; in the case of swim bladders, this connection to the gut continues to exist as the pneumatic duct in the more "primitive" ray-finned fish, and is lost in some of the more derived teleost orders. There are no animals which have both lungs and a swim bladder.

text: The cartilaginous fish (e.g., sharks and rays) split from the other fishes about 420 million years ago, and lack both lungs and swim bladders, suggesting that these structures evolved after that split.[10] Correspondingly, these fish also have both heterocercal and stiff, wing-like pectoral fins which provide the necessary lift needed due to the lack of swim bladders. Teleost fish with swim bladders have neutral buoyancy, and have no need for this lift.[11]

text: Deep scattering layer[edit]

text: Sonar operators, using the newly developed sonar technology during World War II, were puzzled by what appeared to be a false sea floor 300–500 metres deep at day, and less deep at night. This turned out to be due to millions of marine organisms, most particularly small mesopelagic fish, with swimbladders that reflected the sonar. These organisms migrate up into shallower water at dusk to feed on plankton. The layer is deeper when the moon is out, and can become shallower when clouds obscure the moon.[12]

text: Most mesopelagic fish make daily vertical migrations, moving at night into the epipelagic zone, often following similar migrations of zooplankton, and returning to the depths for safety during the day.[13][14] These vertical migrations often occur over large vertical distances, and are undertaken with the assistance of a swim bladder. The swim bladder is inflated when the fish wants to move up, and, given the high pressures in the mesoplegic zone, this requires significant energy. As the fish ascends, the pressure in the swimbladder must adjust to prevent it from bursting. When the fish wants to return to the depths, the swimbladder is deflated.[15] Some mesopelagic fishes make daily migrations through the thermocline, where the temperature changes between 10 and 20 °C, thus displaying considerable tolerance for temperature change.

text: Sampling via deep trawling indicates that lanternfish account for as much as 65% of all deep sea fish biomass.[16] Indeed, lanternfish are among the most widely distributed, populous, and diverse of all vertebrates, playing an important ecological role as prey for larger organisms. The estimated global biomass of lanternfish is 550–660 million metric tonnes, several times the entire world fisheries catch. Lanternfish also account for much of the biomass responsible for the deep scattering layer of the world's oceans. Sonar reflects off the millions of lanternfish swim bladders, giving the appearance of a false bottom.[17]

text: Human uses[edit]

text: In some Asian cultures, the swim bladders of certain large fishes are considered a food delicacy. In China they are known as fish maw, 花膠/鱼鳔,[18] and are served in soups or stews.

text: The vanity price of a vanishing kind of maw is behind the imminent extinction of the vaquita, the world's smallest dolphin breed. Only found in Mexico's Gulf of California, the once numerous vaquita now number less than 60 in total. Vaquita die in gillnets[19] set to catch totoaba (the world's largest drum fish). Totoaba are being hunted to extinction for its maw, which can sell for as much $10,000 per kilogram.

text: Swim bladders are also used in the food industry as a source of collagen. They can be made into a strong, water-resistant glue, or used to make isinglass for the clarification of beer.[citation needed] In earlier times they were used to make condoms.[20]

text: Swim bladder disease[edit]

text: Swim bladder disease is a common ailment in aquarium fish. A fish with swim bladder disorder can float nose down tail up, or can float to the top or sink to the bottom of the aquarium.[21]

text: Risk of injury[edit]

text: Many anthropogenic activities, like pile driving or even Seismic wave, that could result from climate change or natural causes, can create high-intensity sound waves that cause a certain amount of damage to fish that possess a gas bladder. Physostomes can release air in order to decrease the tension in the gas bladder that may cause internal injuries to other vital organs. While physoclisti can't expel air fast enough, making it more difficult to avoid any major injuries.[22] Some of the commonly seen injuries included ruptured gas bladder and renal Haemorrhage. These mostly affect the overall health of the fish and didn't affect their mortality rate.[22] Investigators used the High-Intensity-Controlled Impedance Fluid Filled (HICI-FT), a stainless-steel wave tube with a electromagnetic shaker. It simulates high-energy sound waves in aquatic far-field, plane-wave acoustic conditions.[23][24]

text: Similar structures in other organisms[edit]

text: Siphonophores have a special swim bladder that allows the jellyfish-like colonies to float along the surface of the water while their tentacles trail below. This organ is unrelated to the one in fish.[25]

text: Gallery[edit]

text:
Swim bladder display in a Malacca shopping mall

Fish maw soup

Swim bladder disease has resulted in this female ryukin goldfish floating upside down


document_title: Types of marriages

question_text: in the united states the only legally sanctioned form of marriage is

text: Types of marriages

text: Americas and Europe[edit]

text: In the Americas and Europe, in the 21st century, legally recognized marriages are formally presumed to be monogamous (although some pockets of society accept polygamy socially, if not legally, and some couples choose to enter into open marriages). In these countries, divorce is relatively simple and socially accepted. In the West, the prevailing view toward marriage today is that it is based on a legal covenant recognizing emotional attachment between the partners and entered into voluntarily.

text: In the West, marriage has evolved from a life-time covenant that can only be broken by fault or death to a contract that can be broken by either party at will. Other shifts in Western marriage since World War I include:

text:
There emerged a preference for maternal custody of children after divorce, as custody was more often settled based on the best interests of the child, rather than strictly awarding custody to the parent of greater financial means.
Both spouses have a formal duty of spousal support in the event of divorce (no longer just the husband)[clarification needed]
Out of wedlock children have the same rights of support as legitimate children
In most countries, rape within marriage is illegal and can be punished
Spouses may no longer physically abuse their partners and women retain their legal rights upon marriage.
In some jurisdictions, property acquired since marriage is not owned by the title-holder. This property is considered marital and to be divided among the spouses by community property law or equitable distribution via the courts.
Marriages are more likely to be a product of mutual love, rather than economic necessity or a formal arrangement among families.
Remaining single by choice is increasingly viewed as socially acceptable and there is less pressure on young couples to marry. Marriage is no longer obligatory.
Interracial marriage is no longer forbidden.

text: Asia and Africa[edit]

text: Key facts concerning the marriage law in Africa and Asia:

text:
Marital rape is legal in most parts Africa and Asia alike.
Child marriage is legal in most parts of Africa and Asia alike.
Arranged marriage is prevalent in many parts of Africa and Asia alike, especially in rural regions.
Same-sex marriage is illegal in most parts of Africa and Asia alike.
Polygamy is legal in many parts of Africa and Asia, but tends to be illegal in most Communist countries and legal in most Muslim countries
Divorce is legal in all parts in Africa and Asia, but wives seeking divorce have fewer legal rights than husbands in Muslim countries than in Communist countries.
Dowries are a traditional aspect of marriage customs in most rural regions of Africa and Asia alike.

text: Some societies permit polygamy, in which a man could have multiple wives; even in such societies however, most men have only one. In such societies, having multiple wives is generally considered a sign of wealth and power. The status of multiple wives has varied from one society to another.

text: In Imperial China, formal marriage was sanctioned only between a man and a woman, although among the upper classes, the primary wife was an arranged marriage with an elaborate formal ceremony while concubines could be taken on later with minimal ceremony. After the rise of Communism, only strictly monogamous marital relationships are permitted, although divorce is a relatively simple process.

text: Monogamy, polyandry, and polygyny[edit]

text: Polyandry (a woman having multiple husbands) occurs very rarely in a few isolated tribal societies. These societies include some bands of the Canadian Inuit,[citation needed] although the practice has declined sharply in the 20th century due to their conversion from tribal religion to Christianity by Moravian missionaries. Additionally, the Spartans were notable for practicing polyandry.[1]

text: Societies which permit group marriage are extremely rare, but have existed in Utopian societies such as the Oneida Community.[citation needed]

text: Today, many married people practice various forms of consensual nonmonogamy, including polyamory and Swinging. These people have agreements with their spouses that permit other intimate relationships or sexual partners. Therefore, the concept of marriage need not necessarily hinge on sexual or emotional monogamy.

text: Christian acceptance of monogamy[edit]

text: In the Christian society, a "one man one woman" model for the Christian marriage was advocated by Saint Augustine (354-439 AD) with his published letter The Good of Marriage. To discourage polygamy, he wrote it "was lawful among the ancient fathers: whether it be lawful now also, I would not hastily pronounce. For there is not now necessity of begetting children, as there then was, when, even when wives bear children, it was allowed, in order to a more numerous posterity, to marry other wives in addition, which now is certainly not lawful." (chapter 15, paragraph 17) Sermons from St. Augustine's letters were popular and influential. In 534 AD Roman Emperor Justinian criminalized all but monogamous man/woman sex within the confines of marriage. The Codex Justinianus was the basis of European law for 1,000 years.

text: Several exceptions have existed for various Biblical figures, incestuous relationships such as Abraham and Sarah,[2] Nachor and Melcha,[3] Lot and his Daughters,[4] Amram and Jochabed[5] and more.[6][7][8]

text: Christianity for the past several years has continued to insist on monogamy as an essential of marriage.

text: Contemporary Western societies[edit]

text: In 21st century Western societies, bigamy is illegal and sexual relations outside marriage are generally frowned-upon, though there is a minority view accepting (or even advocating) open marriage.

text: However, divorce and remarriage are relatively easy to undertake in these societies. This has led to a practice called serial monogamy, which involves entering into successive marriages over time. Serial monogamy is also sometimes used to refer to cases where the couples cohabitate without getting married.

text: Unique practices[edit]

text: Some parts of India follow a custom in which the groom is required to marry with an auspicious plant called Tulsi before a second marriage to overcome inauspicious predictions about the health of the husband. This also applies if the prospective wife is considered to be 'bad luck' or a 'bad omen' astrologically. However, the relationship is not consummated and does not affect their ability to remarry later.[citation needed]

text: In the state of Kerala, India, the Nambudiri Brahmin caste traditionally practiced henogamy, in which only the eldest son in each family was permitted to marry. The younger children could have sambandha (temporary relationship) with Kshatriya or Nair women. This is no longer practiced, and in general the Nambudiri Brahmin men marry only from the Nambudiri caste and Nair women prefer to be married to Nair men. Tibetan fraternal polyandry (see Polyandry in Tibet) follows a similar pattern, in which multiple sons in a family all marry the same wife, so the family property is preserved; leftover daughters either become celibate Buddhist nuns or independent households. It was formerly practiced in Tibet and nearby Himalayan areas, and while it was discouraged by the Chinese after their conquest of the region, it is becoming more common again.[9]

text: In Mormonism, a couple may seal their marriage "for time and for all eternity" through a "sealing" ceremony conducted within LDS Temples. The couple is then believed to be bound to each other in marriage throughout eternity if they live according to their covenants made in the ceremony. Mormonism also allows living persons to act as proxies in the sealing ceremony to "seal" a marriage between ancestors who have been dead for at least one year and who were married during their lifetime. According to LDS theology, it is then up to the deceased individuals to accept or reject this sealing in the spirit world before their eventual resurrection. A living person can also be sealed to his or her deceased spouse, with another person (of the same sex as the deceased) acting as proxy for that deceased individual.[citation needed]

text: One society that traditionally did without marriage entirely was that of the Na of Yunnan province in southern China. According to anthropologist Cia Hua, sexual liaisons among the Na took place in the form of "visits" initiated by either men or women, each of whom might have two or three partners each at any given time (and as many as two hundred throughout a lifetime). The nonexistence of fathers in the Na family unit was consistent with their practice of matrilineality and matrilocality, in which siblings and their offspring lived with their maternal relatives. In recent years, the Chinese state has encouraged the Na to acculturate to the monogamous marriage norms of greater China. Such programs have included land grants to monogamous Na families, conscription (in the 1970s, couples were rounded up in villages ten or twenty at a time and issued marriage licenses), legislation declaring frequent sexual partners married and outlawing "visits", and the withholding of food rations from children who could not identify their fathers.[citation needed] Many of these measures were relaxed in favor of educational approaches after Deng Xiaoping came into power in 1981. See also the Mosuo ethnic minority of China and their practice of walking marriage.

text: Types of marriages[edit]

text:
Arranged marriage – A marriage that is at some level arranged by someone other than those being married. Cf Matchmaking.

Heqin – An arranged marriage for political alliance during Medieval China.
Shim-pua marriage – A Taiwanese tradition of arranged marriage, in which a poor family (burdened by too many children) would sell a young daughter to a richer family for labour, and in exchange, the poorer family would be married into the richer family, through the daughter.

Avunculate marriage – Marrying one's own uncle or aunt. Cf. inbreeding and incest.
Beena marriage – A form of marriage used in pre-Islamic Arabia, in which a wife would own a tent of her own, within which she retained complete independence from her husband, a form of matriarchy.
Boston marriage – A marriage-like relationship between two women, not necessarily sexual; also historic lesbian relationships.
Celestial marriage – A marriage performed in a Latter Day Saint (Mormon) temple.
Child marriage – A practice in which the one or both spouses are prepubescents, while not necessarily below the legal marriageable age. Cf. teen marriage.
Civil marriage – A marriage performed, recorded, and recognized by a government official; such a marriage may be performed by a religious body and recognized by the state, or entirely secular.
Common-law marriage – A form of interpersonal status that is legally recognized in some jurisdictions as a marriage even though no legally recognized marriage ceremony is performed, no contract is explicitly entered into, and no registry is made of the union. Cf customary law.
Cousin marriage – Marriage between first cousins. Cf. inbreeding and incest.
Covenant marriage – A marriage in which the couple agrees to obtain pre-marital counseling before marrying, and accept more limited grounds for divorce.
Customary marriage – A marriage according to the customary law of a particular social group, which may or may not be recognised by the state. Cf Common-law marriage.
Endogamy – A marriage within the boundaries of the domestic group, between members of the same group.
Exchange marriage – Two (or more) brothers and an equal number of sisters marry. An element of alliance theory much studied by anthropologists such as Claude Lévi-Strauss. Also known as sister exchange, bride exchange, etc. Cf Sororate marriage.

Watta satta – A form of marriage exchange in Pakistan and Afghanistan, involving two simultaneous marriages of a brother-sister pair from two households.

Exogamy or Intermarriage – Marriage between people belonging to different groups or backgrounds.

Inter-caste marriage – Marriage between persons from different castes. Cf Hypergamy.
Interracial marriage – Marriage between two people of differing races.
Interreligious marriage – Marriage (either religious or civil) between partners professing different religions.
Royal intermarriage – Marriage between members of different royal families, dynasties, or houses.
Transnational marriage – Marriage to persons from different countries.

Female husband marriage – A marriage in which a female takes a wife; see e.g. the Nandi people; also known in the anthropological literature as woman-to-woman or female-to-female marriage.
Female-led marriage – A monogamous, heterosexual marriage in which both partners agree that the woman will act as the leader, principal partner and ultimate authority of the relationship, commonly referred to as an FLR.
Flash marriage – the English translation of a recent Chinese expression, denoting a speedy marriage between couples who don't really know one another. Cf. Las Vegas wedding and Nikah 'urfi.
Fleet Marriage – The best-known example of an irregular or a clandestine marriage taking place in England before the Marriage Act 1753.
Forced marriage – A marriage in which one or more of the parties is married without his/her consent or against his/her will.

Marriage by abduction – Also known as marriage by capture or bride kidnapping. A form of forced marriage in which a woman who is kidnapped and raped by a man is thereafter regarded as his wife.
Raptio is a Latin term referring to the large scale abduction of women, usually in warfare, either for marriage or for rape

Group marriage – A form of polygamous marriage in which more than one man and more than one woman form a family unit, and all members of the marriage share parental responsibility for any children arising from the marriage.

Line marriage – A form of group marriage in which the family unit continues to add new spouses of both sexes over time so that the marriage does not end.

Handfasting – A traditional European ceremony of marriage or betrothal, commonly practiced by Neopagans today, which may or may not result in a legally recognized marriage. Cf Jumping the broom.
Hollywood marriage – A marriage between Hollywood celebrities or a marriage that is of short duration and quickly ends in separation or divorce.
Human-animal marriage – A marriage between a human and a non-human animal. A trope in fiction and mythology.
Hypergamy – Marriage for the purpose of upward mobility.
Lavender marriage – A marriage between a man and a woman in which one, or both, parties are, or are assumed to be, homosexual.
Love marriage – A marriage where the basis for the marriage is love. Cf. sham marriage and forced marriage.
Marriage of convenience – A marriage intended to serve some pragmatic purpose, not a love marriage. Cf. sham marriage.
Mixed-orientation marriage – A marriage where one spouse has a different sexual orientation than the other spouse.
Monogamy – Marriage with one spouse exclusively for life or for a period of time. Cf. serial monogamy
Morganatic marriage – A marriage which can be contracted in certain countries, usually between persons of unequal social rank, which prevents the passage of the husband's titles and privileges to the wife and any children born of the marriage.
Muslim marriage – One of several types. See Islamic marital jurisprudence
Naked marriage – the English translation of a recent Chinese slang term, denoting a marriage begun without many possessions or wealth.
Nikah 'urfi –a type of informal marriage in some Islamic traditions, see Islamic marital jurisprudence. Cf. Las Vegas wedding.
Open marriage – A marriage in which the partners agree that each is free to engage in extramarital sexual relationships, without regarding this as sexual infidelity.
Plaçage – A recognized extralegal system in which white French and Spanish and later Creole men entered into the equivalent of common-law marriages with women of African, Indian and white (European) Creole descent. Cf. concubinage
Polygamy – Plural marriage:

Bigamy – One person having two spouses. In English, the word usually denotes a crime, i.e. a sham marriage.
Polyandry – The marriage of one wife to several husbands. Fraternal polyandry is a variant in which the husbands are brothers (see Polyandry in Tibet.)
Polygyny – The marriage of one husband to several wives.

Posthumous marriage – A marriage which occurs after one or both parties is deceased.

Ghost marriage in Sudan – The marriage of a woman to a man who died before he could marry, using the man's brother as a stand-in. Cf Proxy marriage
Ghost marriage in China

Proxy marriage – Marriage ceremony during which the wedding couple is not in the same physical location.
Putative marriage – An apparently valid marriage, entered into in good faith on part of at least one of the partners, which is invalid because of an impediment. Cf. void marriage.
Remarriage – Entering into a new marriage, after the end of the previous one, e.g. by death or divorce. Cf. serial monogamy.
Same-sex marriage – A marriage between spouses of the same sex.
Self-marriage – A marriage by a person to himself or herself.
Self-uniting marriage – A marriage in which the two partners dispense with the presence of a third-party officiant.
Sexless marriage or mariage blanc – A marriage in which there is no sex (and, in the latter case, perhaps never was) between the two partners. Cf. marriage of convenience.
Sham marriage – Marriage as a pretext to commit fraud. Cf. green card marriage and voidable marriage.
Shared Earning/Shared Parenting Marriage – A type of marriage popular in various countries where the partners choose at the outset of the marriage to share the work of childraising, earning money, housework and recreation time in nearly equal fashion across all four domains. Also known as peer marriage.
Shotgun marriage – A marriage hastily arranged, often with the implication of the bride's unintended pregnancy.
Sororate marriage – A marriage in which a man marries his wife's sister, usually after the wife is dead or has proved infertile.
Teen marriage – A practice in which the one or both spouses are teenagers below age of majority, while not necessarily below the legal marriageable age. Cf. child marriage.
Trial marriage – A situation were the couples agree to stay together without formalising or legalising the relationship as they wait to see whether it is going to work out.
Walking marriage – A practice of a matrifocal group in which the husband spends the nights with his wife, but he departs in the morning to work in his mother's household.
Widow inheritance – Also known as bride inheritance. A cultural and social practice whereby a widow is required to marry a male relative of her late husband, often his brother.

Levirate marriage – is a type of marriage in which the brother of a deceased man is obliged to marry his brother's widow, and the widow is obliged to marry her deceased husband's brother.
Sudanese ghost marriage
Yibbum, according to Jewish Torah law, the brother of a man who died without children has an obligation to marry the widow.
Widow conservation – an obsolete form of marriage in early Protestant Europe, when the widow of a parish vicar was remarried to her husband's successor to ensure her economic support.

Wedlease/Temporary marriage – A contract entailing a brief, fixed-term marital status:

Nikah mut‘ah
Nikah Misyar

Yogic marriage – A tradition of Hindu marriage done within Shavite Sadhus and Sadhvis, to enable them to get positive energy


document_title: List of countries by proven oil reserves

question_text: who has more oil saudi arabia or usa

question_tokens: who has more oil saudi arabia or usa

text: Countries[edit]

text: Reserves amounts are listed in millions of barrels (MMbbl). The column "Years until exhaustion" uses the daily production figures as of 2016 [1] (multiplied with 365).

text:
Proven reserves (millions of barrels)

U.S. EIA (start of 2017)[2]

OPEC (end of 2015)[3]

BP (end of 2015)[4]

Other

Years until exhaustion

Country

Rank

Reserves

Rank

Reserves

Rank

Reserves

Source/Date

Reserves

Production per year(MMbbl/year, 2016)[1]

Years

 Venezuela (see: Oil reserves in Venezuela)
1
300,878
1
300,878
1
300,900

831.1
362

 Saudi Arabia (see: Oil reserves in Saudi Arabia)
2
266,455
2
266,455
2
266,600

3818.1
69

 Canada (see: Oil reserves in Canada)
3
169,709
26
4,118[5]
3
172,200
Natural Resources Canada, end 2014[6]
171,000
1336.8
126

 Iran (see: Oil reserves in Iran)

4

158,400

3

158,400

4

157,800

1452.9
109

 Iraq (see: Oil reserves in Iraq)
5
142,503
4
142,503
5
143,100

1624.8
88

 Kuwait (see: Oil reserves in Kuwait)
6
101,500
5
101,500
7
101,500

1067.2
95

 UAE (see: Oil reserves in the United Arab Emirates)
7
97,800
6
97,800
8
97,800

1133.7
86

 Russia (see: Oil reserves in Russia)
8
80,000
7
80,000
6
102,400

3851.3
21

 Libya (see: Oil reserves in Libya)
9
48,000
8
74,363
9
78,400

366.1
131

 Nigeria (see: Oil reserves in Nigeria)
10
37,062
9
37,062
11
37,100

730.0
51

 United States (see: Oil reserves in the United States)
11
35,000
10
36,685
10
55,000
ENI, end of 2015[7]
43,629
3239.7
10

 Kazakhstan
12
30,000
11
30,000
12
30,000

582.2
52

 China
13
25,620
13
25,132
14
18,500

1452.9
17

 Qatar
14
25,244
12
25,244
13
25,244

555.9
45

 Brazil
15
12,999
14
16,184
15
13,000
ENI, end of 2015[7]
16,848
918.1
14

 Algeria
16
12,200
15
12,200
17
12,200

492.1
25

 Angola
17 / 18
8,273
17
9,524
16
12,700

645.9
22

 Ecuador
17 / 18
8,273
18
8,273
19 / 20
8,000

200.2
41

 Mexico (see: Oil reserves in Mexico)
19
7,300
16
9,711
18
10,800
PEMEX[8] Start of 2015
9.700
798.2
9

 Azerbaijan
20
7,000
19
7,000
21
7,000

304.2
23

 Norway
21
6,611
33
5,139
19 / 20
8,000

601.5
11

 Oman
22
5,373
21
5,306
23
5,300

367.5
23

 Sudan/South Sudan
23
5,000
32
5,000
24
Sudan 1,500 / S. Sudan 3,500

93.1
53

 India
24
4,600
20
5,680
22
5,680
ENI, end of 2015[7]
5,692
267
17

 Egypt
25 / 26
4,400
24 / 25
4,400
29
3,500

180.4
24

 Vietnam
25 / 26
4,400
24 / 25
4,400
25
4,000

110.2
40

 Indonesia
27 / 28
3,600
29
3,230
27 / 28
3,600
ENI, end of 2015[7]
3,497
304.2
11

 Malaysia
27 / 28
3,600
28
3,750
27 / 28
3,600
ENI, end of 2015[7]
5,542
241.3
15

 Yemen
29
3,000

30
3,000

 United Kingdom
30
2,564
30
2,755
31
2,800
UK Oil & Gas Authority, end 2015[9]
2,618
343.1
7.5

 Syria
31 / 32
2,500
31
2,500
32
2,500

 Uganda
31 / 32
2,500

 Argentina
33
2,185
32
2,380
33
2,400
Argentine Petroleum Institute[10]
2,330

 Colombia
34
2,002
33
2,308
34
2,300

 Gabon
35
2,000
34
2,000
35
2,000

 Australia
36
1,821
27
3,982
26
4,000
Geoscience Australia[11] end of 2014
4,002

 Congo, Republic of the (Brazzaville)
37
1,600

36
1,600

 Chad
38
1,500

37
1,500

 Brunei
39 / 40
1,100
35
1,100
39 / 40
1,100

 Equatorial Guinea
39 / 40
1,100

39 / 40
1,100

 Ghana (see: Oil reserves in Ghana)
41
660

 Romania
42 / 43
600

42 / 46
600

 Turkmenistan
42 / 43
600
36
600
42 / 46
600

 Uzbekistan
44
594
37
594
42 / 46
600

 Italy
45
557

42 / 46
600
ENI, end of 2015[7]
595

 Denmark
46
491
38
511
42 / 46
600
ENI, end of 2015[7]
550

 Peru
47
473

38
1,400
ENI, end of 2015[7]
1,489

 Tunisia
48
425

47 / 48
400

 Thailand
49
396

47 / 48
400

 Ukraine
50
395
39
395

 Pakistan
51
350

ENI, end of 2015[7]
236

 Turkey
52
300

ENI, end of 2015[7]
284

 Trinidad and Tobago
53
243

41
700
ENI, end of 2015[7]
830

 Bolivia
54
211

ENI, end of 2015[7]
210

 Cameroon
55
200

 Belarus
56
198
40
198

 Congo, Democratic Republic of the (Kinshasa)
57
180

 Albania
58
168

 Papua New Guinea
59
159

ENI, end of 2015[7]
158

 Chile
60 / 62
150

 Niger
60 / 62
150

 Spain
60 / 62
150

 Germany
63
145

ENI, end of 2015[7]
229

 Myanmar
64
139

 Philippines
65
139

 Poland
66
138

ENI, end of 2015[7]
151

 Bahrain
67
125

 Cuba (see: Oil reserves in Cuba)
68
124

ENI, end of 2015[7]
124

 Netherlands
69
113

ENI, end of 2015[7]
141

 Ivory Coast
70
100

 Suriname
70
83.9

 Guatemala
71
83.1

 France
72
72.4

 Serbia
73
77.5

 Croatia
74
71.0

 New Zealand
75
56.9

 Japan
76
44.1

 Austria
77
43.0

 Kyrgyzstan
78
40.0

 Georgia
79
35.0

 Bangladesh
80
28.0

 Hungary
81
25.1

ENI, end of 2015[7]
35

 Mauritania
82
20.0

 Bulgaria
83 / 85
15.0

 Czech Republic
83 / 85

15.0

 South Africa
83 / 85

15.0

 Israel
86
12.7

ENI, end of 2015[7]
12

 Lithuania
87 / 88
12.0

 Tajikistan
87 / 88
12.0

 Greece
89
10.0

 Slovakia
90
9.00

 Benin
91
8.00

 Belize
92
6.70

 Taiwan
93
2.38

 Barbados
94
2.08

 Jordan
95
1.00

ENI, end of 2015[7]
1

 Morocco
96
0.68

 Ethiopia
97
0.43

 Afghanistan

0

US Geological Survey[12]
80

World total

1,726,685

1,481,526

1,697,600

29427
59

text: Different sources[edit]

text: Sources sometimes differ on the volume of proven oil reserves. The differences sometimes result from different classes of oil included, and sometimes result from different definitions of proven.

text: Comparison of proven oil reserves from some widely used sources (billions of barrels, as of 31 Dec. 2014/1 Jan. 2015)

text:
Source

Canada

Iran

Russia

Saudi Arabia

United States

Venezuela

BP[13]

172.9

157.8

103.2

267.0

48.5

298.3

OPEC[14]

4.2[4]

157.5

80.0

266.6

36.5

300.0

US Central Intelligence Agency[15]

171.0

157.8

103.2

268.3

36.5

298.4

US Energy Information Administration[16]

172.5

157.8

80.0

268.3

39.9

298.4