The Colangüil Batholith is a group of

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 in western

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

between the latitudes of 29 and 31° S. The plutons of the batholith were emplaced and cooled in the Late Paleozoic and the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

. Runs in a north–south direction. The plutons of the batholith are intruded into

volcanic rock Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...

s produced by the same plutons plus some earlier deformed basement. The most common rocks in the batholith are

granodiorite Granodiorite ( ) is a coarse-grained (phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. The term banatite is sometimes used informally for various rocks ranging from gra ...

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, 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 coo ...

and

leucogranite Leucogranite is a light-colored, granitic, igneous rock containing almost no dark minerals. Leucogranites have been reported from a variety of orogenies involving continental collisions. Examples include the Black Hills (Trans-Hudson orogeny ...

. The batholith contains also a

dyke swarm A dike swarm (American spelling) or dyke swarm ( British spelling) is a large geological structure consisting of a major group of parallel, linear, or radially oriented magmatic dikes intruded within continental crust or central volcano ...

of north–south trending dykes. Compared to other subduction-related batholiths around the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

Colangüil Batholith is more

felsic In geology, felsic is a grammatical modifier, 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 ...

. Together with the Chilean Coastal Batholith and the

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 emplaced and cooled in the Late Paleozoic and the earliest Mesozoic. Some of the plut ...

the Colangüil Batholith is a remnant of the

volcanic arc A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc ...

s that erupted the volcanic material of the

Choiyoi Group Choiyoi Group () is a Permian and Triassic-aged group of volcano-sedimentary formations in Argentina and Chile. The group bears evidence of bimodal-style volcanism related to an ancient subduction zone that existed along the western margin of ...

. The batholith is made up six major units: *Granodiorita Las Piedritas (made up by five plutons) *Granito Los Puentes (made up by three plutons) *Granito Las Opeñas (made up by a single pluton) *Granito Agua Blanca (made up by two plutons) *Granito Los Lavaderos (made up by a single pluton) *Riolita Tres Quebradas (

subvolcanic A subvolcanic rock, also known as a hypabyssal rock, is an intrusive rock, intrusive igneous rock that is emplaced at depths less than within the crust (geology), crust, and has intermediate crystallite, grain size and often porphyritic texture be ...

intrusions) Part of the batholith is thought to be covered by thick sedimentary deposits such as those of

Iglesia Basin Iglesia Basin () is a sedimentary basin located in northern San Juan Province, western Argentina. It is thought to be a piggyback basin. Its sedimentary fill is of Neogene to Pleistocene age and has an estimated maximum thickness of 3.5 km. ...

References

Geology of San Juan Province, Argentina Batholiths of South America Lithodemic units of Argentina Permian geology of South America {{SanJuanAR-geo-stub