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 The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...

(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 natural sa ...

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, whi ...

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 undergro ...

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-silic ...

(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 o ...

'').

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 solid ...

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–T ...

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 s ...

, 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 are ...

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 letter ...

god of the underworld

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

). 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'' be ...

. 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 fo ...

, 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 primarily ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. 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 P ...

, 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 Columbia ...

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 tot ...

; 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 distin ...

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 crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric pat ...

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 Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), ...

). 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 smooth ...

Yosemite Valley Yosemite Valley ( ; ''Yosemite'', Miwok for "killer") is a U-shaped valley, glacial valley in Yosemite National Park in the western Sierra Nevada (U.S.), Sierra Nevada mountains of Central California. The valley is about long and deep, surroun ...

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 The Angara-Vitim batholith is group of plutons in the eastern Siberia, just east of Lake Baikal. The batholith formed in the Devonian–Early Carboniferous likely in connection to a mantle plume. It formed about the same time and by the same process ...

, 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 Authorit ...

Fort Batholith,

Telangana Telangana (; , ) is a States and union territories of India, state in India situated on the south-central stretch of the Indian subcontinent, Indian peninsula on the high Deccan Plateau. It is the List of states and union territories of India b ...

, India * Chibagalakh batholith, 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, 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, England * Ljusdal Batholith, 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 lithology, lithological units of the Baltic Shield. It consists of a series of batholiths in Sweden and Norway forming a ca. 140 ...

, 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. Conveni ...

- Plana,

Sofia Sofia ( ; bg, София, Sofiya, ) is the capital and 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. The city is built west of the Iskar river, and ha ...

, Bulgaria

North America

* Bald Rock Batholith *

Boulder Batholith The Boulder Batholith is a relatively small batholith in southwestern Montana, United States, exposed at the surface as granite (more specifically quartz monzonite) and serving as the host rock for rich mineralized deposits at Butte and other loc ...

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 = Brit ...

Chambers-Strathy Batholith The Chambers-Strathy Batholith, also called the Strathy-Chambers Batholith, is a large granitoid batholith complex in the Temagami, Ontario, Temagami region of Northeastern Ontario, Canada. Named for the Chambers Township, Ontario, Chambers and Str ...

Chilliwack batholith The Chilliwack Batholith is a large batholith that forms much of the North Cascades in southwestern British Columbia, Canada and the U.S. state of Washington. The geological structure is named after the Chilliwack River Valley, where it outcrops ...

*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 geo ...

*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 t ...

* 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 on ...

* Wallowa Batholith,

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

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, which ...

, Baja and

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, 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 po ...

* 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 reache ...

*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

Oceania

*Cullen Batholith, Australia * Kosciuszko Batholith, Australia *

Moruya Moruya is a town located on the far south coast of New South Wales, Australia, situated on the Moruya River. The Princes Highway runs through the town that is about south of Sydney and from Canberra. At the , Moruya had a population of 4 ...

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 The Achala Batholith ( es, batolito de Achala) is a group of plutons in the Sierras de Córdoba in central Argentina. With a mapped surface of over 2500 km2 it constitutes the largest group of intrusions exposed in the Sierras Pampeanas. The ol ...

, Argentina * Antioquia Batholith, Colombia *Guanambi Batholith,

Bahia Bahia ( , , ; meaning "bay") is one of the 26 Federative units of Brazil, states of Brazil, located in the Northeast Region, Brazil, Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo (sta ...

, Brazil * Parguaza rapakivi granite Batholith, Venezuela and Colombia *

Cerro Aspero Batholith Cerro Aspero Batholith ( es, batolito de Cerro Aspero) is a group of plutons in southern Sierras Pampeanas in central Argentina. The batholith covers an approximate area of 440 km2 and lies about 50 km south of the larger Achala Batholith. The bath ...

, Argentina *

Coastal Batholith of Peru The Coastal Batholith of Peru ( es, Batolito costero peruano) is a group of hundreds, if not thousands, of individual plutons that crop out near or at the coast of Peru. The batholith runs a length of ca. 1600 km. Most of the plutons of the bat ...

* Colangüil Batholith, Argentina *

Cordillera Blanca Batholith The Cordillera Blanca Batholith ( es, Batolito de la Cordillera Blanca) is an extensive group of individual plutons that crop out near or at Cordillera Blanca, Peru. The batholith intrudes the Jurassic Chicama Formation. To the west the Cordiller ...

, Peru *

Vicuña Mackenna Batholith The Vicuña Mackenna Batholith ( es, Batolito Vicuña Mackenna) is a group of plutons in the Chilean Coast Range of northern Chile. The plutons of the batholith formed (cooled from magma to rock) between the Early Jurassic and the Late Cretaceous ...

, Chile *

Elqui-Limarí Batholith The Elqui-Limarí Batholith is a group of plutons in the Andes of Chile and Argentina between the latitudes of 28 and 30° S. The plutons of the batholith were Methods of pluton emplacement, emplaced and cooled in the Paleozoic, Late Paleozoic and t ...

, Chile and Argentina * Futrono-Riñihue Batholith, Chile * Illescas Batholith, 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 The Panguipulli Batholith is a granitic batholith of Jurassic age located in the Andes around Panguipulli Lake in southern Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southern ...

, Chile *Patagonian Batholith, Chile and Argentina **

North Patagonian Batholith The North Patagonian Batholith ( es, Batolito Nor-Patagónico) is a series of igneous plutons in the Patagonian Andes of Argentina and Chile. Geology The Northern Patagonian Batholith was formed in the Mesozoic Era and Cenozoic Era. It is made u ...

South Patagonian Batholith The South Patagonian Batholith ( es, Batolito Sur-Patagónico) is group of plutons in southwestern Patagonia. The rocks of batholith include granite, leucogranite, tonalite, granodiorite, diorite, gabbro and mafic dykes. The earliest plutons of the ...

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