A batholith () is a large mass of intrusive

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or l ...

(also called

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 ...

rock), larger than in area, that forms from cooled

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 natura ...

deep in

Earth's crust Earth's crust is Earth's thin outer shell of rock, referring to less than 1% of Earth's radius and volume. It is the top component of the lithosphere, a division of Earth's layers that includes the crust and the upper part of the mantle. The ...

. Batholiths are almost always made mostly of

felsic In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, wh ...

or intermediate rock types, such as

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 und ...

quartz monzonite Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclase ...

, or

diorite Diorite ( ) is an intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is intermediate in composition between low-sil ...

(see also ''

granite dome Granite domes are domical hills composed of granite with bare rock exposed over most of the surface. Generally, domical features such as these are known as bornhardts. Bornhardts can form in any type of plutonic rock but are typically composed ...

'').

Formation

Although they may appear uniform, batholiths are in fact structures with complex histories and compositions. They are composed of multiple masses, or ''

pluton In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s'', bodies of igneous rock of irregular dimensions (typically at least several kilometers) that can be distinguished from adjacent igneous rock by some combination of criteria including age, composition, texture, or mappable structures. Individual plutons are solidified from magma that traveled toward the surface from a zone of

partial melting Partial melting occurs when only a portion of a solid is melted. For mixed substances, such as a rock containing several different minerals or a mineral that displays solid solution, this melt can be different from the bulk composition of the soli ...

near the base of the Earth's crust. Vitosha platoto

Traditionally, these plutons have been considered to form by ascent of relatively

buoyant Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pr ...

magma in large masses called ''plutonic

diapir A diapir (; , ) is a type of igneous intrusion in which a more mobile and ductily deformable material is forced into brittle overlying rocks. Depending on the tectonic environment, diapirs can range from idealized mushroom-shaped Rayleigh– ...

s''. Because the diapirs are liquified and very hot, they tend to rise through the surrounding native

country rock Country rock is a genre of music which fuses rock and country. It was developed by rock musicians who began to record country-flavored records in the late 1960s and early 1970s. These musicians recorded rock records using country themes, vocal ...

, pushing it aside and partially melting it. Most diapirs do not reach the surface to form

volcano 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 ...

es, but instead they slow down, cool, and usually solidify 5 to 30 kilometers underground as plutons (hence the use of the word ''pluton''; in reference to the

Roman Roman or Romans most often refers to: *Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD * Roman people, the people of ancient Rome *'' Epistle to the Romans'', shortened to ''Romans'', a lett ...

god of the underworld

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest k ...

). An alternate view is that plutons commonly are formed not by ascent of large magma diapirs, but rather by aggregation of smaller volumes of magma that ascend as

dikes Dyke (UK) or dike (US) may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), a subvertical sheet-like intrusion of magma or sediment * Dike (mythology), ''Dikē'', the Greek goddess of moral justice * Dikes, ...

. A batholith is formed when many plutons converge to form a huge expanse of granitic rock. Some batholiths are mammoth, paralleling past and present

subduction zones 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 other heat sources for hundreds of kilometers in

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called '' sial' ...

. One such batholith is the

Sierra Nevada Batholith The Sierra Nevada Batholith is a large batholith which forms the core of the Sierra Nevada mountain range in California, exposed at the surface as granite. The batholith is composed of many individual masses of rock called '' plutons'', which f ...

, which is a continuous granitic formation that makes up much of the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

. An even larger batholith, the

Coast Plutonic Complex The Coast Range Arc was a large volcanic arc system, extending from northern Washington through British Columbia and the Alaska Panhandle to southwestern Yukon. The Coast Range Arc lies along the western margin of the North American Plate in the ...

, is found predominantly in the

Coast Mountains The Coast Mountains (french: La chaîne Côtière) are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Colum ...

of western

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

; it extends for 1,800 kilometers and reaches into southeastern

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

Surface expression and erosion

A batholith is an exposed area of (mostly) continuous plutonic rock that covers an area larger than 100 square kilometers (40 square miles). Areas smaller than 100 square kilometers are called ''

stocks Stocks are feet restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law describing ...

''. However, the majority of batholiths visible at the surface (via outcroppings) have areas far greater than 100 square kilometers. These areas are exposed to the surface through the process of

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 di ...

accelerated by continental uplift acting over many tens of millions to hundreds of millions of years. This process has removed several tens of square kilometers of overlying rock in many areas, exposing the once deeply buried batholiths. Batholiths exposed at the surface are subjected to huge pressure differences between their former location deep in the earth and their new location at or near the surface. As a result, their

crystal structure In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns t ...

expands slightly over time. This manifests itself by a form of

mass wasting Mass wasting, also known as mass movement, is a general term for the movement of rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is not entrained in ...

called exfoliation. This form of weathering causes convex and relatively thin sheets of rock to slough off the exposed surfaces of batholiths (a process accelerated by frost wedging). The result is fairly clean and rounded rock faces. A well-known result of this process is

Half Dome Half Dome is a granite dome at the eastern end of Yosemite Valley in Yosemite National Park, California. It is a well-known rock formation in the park, named for its distinct shape. One side is a sheer face while the other three sides are smoot ...

Yosemite Valley Yosemite Valley ( ; ''Yosemite'', Miwok for "killer") is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of Central California. The valley is about long and deep, surrounded by high granite summits such as ...

Examples

Africa

*Aswan Granite Batholith *Cape Coast Batholith, Ghana *Heerenveen Batholith, South Africa *Paarl Rock, South Africa *Darling Batholith, South Africa *

Hook granite massif The Hook granite massif is a large formation in central Zambia formed around 550 million years ago during the Pan-African orogeny. It lies in the inner part of the Lufilian arc. Today, the south-western extension of the massif lies under the Kafue ...

, Zambia *Mubende Batholith, Uganda

Antarctica

*Antarctic Peninsula Batholith *Queen Maud Batholith

Asia

* Angara-Vitim batholith, Siberia *

Bhongir Bhongir, officially known as, Bhuvanagiri is a district headquarters of the Yadadri Bhuvanagiri district and part of the Hyderabad Metropolitan Region of the Indian state of Telangana. Falling under Hyderabad Metropolitan Development Authority ...

Fort Batholith,

Telangana Telangana (; , ) is a state in India situated on the south-central stretch of the Indian peninsula on the high Deccan Plateau. It is the eleventh-largest state and the twelfth-most populated state in India with a geographical area of and ...

, India *

Chibagalakh batholith The Chibagalakh Range ( rus, Чибагала̀хский хребет; sah, Чыбаҕалаах) is a mountain range in the Sakha Republic (Yakutia), Far Eastern Federal District, Russia. Despite the beauty of its landscapes the range is rare ...

, Siberia *Mount Abu, India *

Gangdese batholith The Gangdese batholith or Gangdese volcanic arc is a major geological structure in the south of the Lhasa terrane in Tibet, to the north of the Himalayas. The batholith formed around 100 million years ago, and was volcanically active for about 2 ...

, Himalaya *Trans-Himalayan Batholith, Himalaya *

Kalba-Narym batholith The Kalba-Narym batholith or Kalba-Narym granitic batholith is group of plutons and intrusions in the northeastern half of Kazakhstan. The batholith formed in the Early Permian and is part of the Central Asian Orogenic Belt. It formed in connection ...

, Kazakhstan *Karakorum Batholith, Himalaya *Tak batholith, Thailand *Tien Shan batholith, Central Asia *Ranchi batholith, India

Europe

*Bindal Batholith, Norway *

Cornubian batholith The Cornubian batholith is a large mass of granite rock, formed about 280 million years ago, which lies beneath much of Devon and Cornwall, the south-western peninsula of Great Britain. The main exposed masses of granite are seen at Dartmoor, Bo ...

, England *Corsica-Sardinia Batholith *

Donegal batholith The Donegal batholith is a large granitic igneous intrusion of early Devonian age that outcrops in County Donegal in Ireland. It consists of at least eight separate plutons, the largest of which is the Main Donegal Granite. It was intruded at a la ...

, Ireland *Leinster Batholith, Ireland *Mancellian batholith, France *

North Pennine Batholith The North Pennine Batholith, also known as the Weardale Granite is a granitic batholith lying under northeast England, emplaced around 400 million years ago in the early Devonian.Kimbell, G.S., B. Young, D. Millward and Q. G. Crowley (2010). 'The ...

, England *

Ljusdal Batholith The Ljusdal Batholith is a group of plutons in central Sweden formed during the Svecofennian orogeny. The batholith occupies a NW-SE elongated area of c. 130 x 100 km covering most of Hälsingland. The Ljusdal Bathoilith is mostly made up of granito ...

, Sweden * Mt-Louis-Andorra Batholith *Riga Batholith, Latvia *Salmi Batholith, Republic of Karelia, Russia *Sunnhordaland Batholith, Norway *

Transscandinavian Igneous Belt The Transscandinavian Igneous Belt ( sv, Transskandinaviska magmatiska bältet), abbreviated TIB, is one of the major lithological units of the Baltic Shield. It consists of a series of batholiths in Sweden and Norway forming a ca. 1400 km l ...

, Sweden and Norway :*Revsund Massif :*Rätan Batholith :*Småland–Värmland Belt *

Vitosha Vitosha ( bg, Витоша ), the ancient ''Scomius'' or ''Scombrus'', is a mountain massif, on the outskirts of Sofia, the capital of Bulgaria. Vitosha is one of the symbols of Sofia and the closest site for hiking, alpinism and skiing. Conve ...

- Plana,

Sofia Sofia ( ; bg, София, Sofiya, ) is the Capital city, capital and List of cities and towns in Bulgaria, largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain in the western parts of the country. ...

, Bulgaria

North America

* Bald Rock Batholith * Boulder Batholith *

British Virgin Islands ) , anthem = " God Save the King" , song_type = Territorial song , song = "Oh, Beautiful Virgin Islands" , image_map = File:British Virgin Islands on the globe (Americas centered).svg , map_caption = , mapsize = 290px , image_map2 = Bri ...

* Chambers-Strathy Batholith *

Chilliwack batholith The Chilliwack Batholith is a large batholith A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mo ...

*Golden Horn Batholith *

Idaho Batholith The Idaho Batholith is a granitic and granodioritic batholith of Cretaceous-Paleogene age that covers approximately of central Idaho and adjacent Montana. The batholith has two lobes that are separate from each other geographically and geologi ...

*Ilimaussaq Batholith,

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is ...

* Kenosha Batholith * Mount Stewart Batholith,

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

* Wallowa Batholith,

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...

Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, whic ...

, Baja and

Southern California Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most populous urban ...

* Pike's Peak Granite Batholith *

Ruby Mountains The Ruby Mountains are a mountain range, primarily located within Elko County with a small extension into White Pine County, in Nevada, United States. Most of the range is included within the Humboldt-Toiyabe National Forest. The range reaches ...

*Rio Verde Batholith, Mexico * San Lorenzo Batholith,

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

* South Mountain Batholith, Nova Scotia * Town Mountain Granite batholith, Texas *

Wyoming batholith The Wyoming batholith is a granite batholith of Neoarchean origin —which forms the eroded core of the Granite and Laramie Mountains in central Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion ...

Oceania

*Cullen Batholith, Australia * Kosciuszko Batholith, Australia * Moruya Batholith, Australia * Scottsdale Batholith, Australia Stratigraphic revision and remapping of the Mathinna Supergroup between the River Tamar and the Scottsdale Batholith, northeast Tasmania
Department of Infrastructure, Energy and Resources. Mineral Resources Tasmania. June 2011 *Median Batholith, New Zealand *New England Batholith, Australia

South America

* Achala Batholith, Argentina *

Antioquia Batholith The Antioquia Batholith ( es, Batolito Antioqueño, Ksta, Kqd, K2ba) is a cluster of plutons located in and named after Antioquia, Colombia. The plutons stretch over an area of about , and intruded and cooled in Late Cretaceous times. Much of the ...

, Colombia *Guanambi Batholith,

Bahia Bahia ( , , ; meaning "bay") is one of the 26 states of Brazil, located in the Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo, Minas Gerais, and Rio de Janeiro) and the 5th-largest ...

, Brazil * Parguaza rapakivi granite Batholith, Venezuela and Colombia * Cerro Aspero Batholith, Argentina * Coastal Batholith of Peru *

Colangüil Batholith The Colangüil Batholith is a group of plutons in western Argentina between the latitudes of 29 and 31° S. The plutons of the batholith were emplaced and cooled in the Late Paleozoic and the Triassic. Runs in a north-south direction. The plutons o ...

, Argentina * Cordillera Blanca Batholith, Peru * Vicuña Mackenna Batholith, Chile * Elqui-Limarí Batholith, Chile and Argentina *

Futrono-Riñihue Batholith The Futrono-Riñihue Batholith ( es, Batolito Futrono-Riñihue) is a group of plutons in the Andes of Los Ríos Region, Zona Sur, southern Chile. The plutons date to the Permian.Campos C., Alberto; Moreno R., Hugo; Muñoz B., Jorge; Antinao R., Jo ...

, Chile *

Illescas Batholith Illescas Batholith is a geological complex located in Uruguay made up of various plutons including rapakivi granite Rapakivi granite is a hornblende-biotite granite containing large round crystals of orthoclase each with a rim of oligoclase (a ...

, Uruguay *

Coastal Batholith of central Chile The Coastal Batholith of central Chile is a group of plutons in the Chilean Coast Range of Central Chile appearing contiguously from 33° S to 38° S. At a latitude of 40° S an outlying group of plutons of the batholith appear in a more eastward ...

* Panguipulli Batholith, Chile *Patagonian Batholith, Chile and Argentina ** North Patagonian Batholith ** South Patagonian Batholith

References

* Plummer, McGeary, Carlson, ''Physical Geology'', Eighth Edition (McGraw-Hill: Boston, 1999) pages 61–63 * Glazner, Bartley, Coleman, Gray, Taylor
Are plutons assembled over millions of years by amalgamation from small magma chambers?
GSA Today: Vol. 14, No. 4, pp. 4–11

External links

{{Authority control Volcanism