Coastal Batholith of central Chile

{{Short description|Igneous rock formation in central Chile}}

{{Infobox rockunit

| name = Coastal Batholith of central Chile

| age = Pennsylvanian
{{fossil range|322.0|297.6}}

| period = Pennsylvanian

| image = Piedra del Aguila Angol, Chile.jpg

| imagesize =

| caption = Araucarias growing on top of rocks of the Coastal Batholith, Cordillera de Nahuelbuta

| type = Batholith

| prilithology = Calc-alkaline magma series

| otherlithology =

| unitof = Central Chile, Andes

| subunits =

| underlies =

| overlies =

| thickness =

| area =

| map = Geological sketch map of central Chile 33° and 40°S with the Coastal Batholith and rocks of the accretionary metamorphic prism - age data are U-Pb zircon crystallization ages.jpg

| map_caption = Geological sketch map of central Chile 33° and 40°S with the Coastal Batholith and rocks of the accretionary metamorphic prism - age data are U-Pb zircon crystallization ages

| location = Chilean Coast Range

| coordinates = {{coord|37|30|S|73|00|W|display=inline,title}}

| region = Araucanía, Biobío, Los Ríos, Maule, O'Higgins, Santiago Metropolitan & Valparaíso Regions

| country = Chile

| extent =

| namedfor =

| namedby =

| year_ts =

}}

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.{{cite journal |last1=Deckart |first1=Katja |last2=Hervé |first2=Francisco |last3=Fanning |first3=C. Mark |last5=Calderón |first5=Mauricio |last4=Ramírez |first4=Valeria |last6=Godoy |first6=Estanislao |author-link2=Francisco Hervé |date=2014 |title=U-Pb Geochronology and Hf-O Isotopes of zircons from the Pennsylvanian Coastal Batholith, South-Central Chile |url=http://www.andeangeology.cl/index.php/revista1/article/view/V41n1-a03/html |journal=Andean Geology |volume=41 |issue=1 |doi=10.5027/andgeoV41n1-a03 |access-date=5 January 2016|doi-access=free |hdl=1885/57884 |hdl-access=free }} At a latitude of 40° S an outlying group of plutons of the batholith appear in a more eastward position in the Andes.

Together with the Elqui-Limarí Batholith and the Colangüil Batholith, the Coastal Batholith of central Chile is a remnant of the volcanic arcs that erupted the volcanic material of the Choiyoi Group. During the Permian the zone of arc magmatism moved from the Coastal Batholith 350 km inland reaching San Rafael about 280 million years ago.{{cite journal |last1=Kleiman |first1=Laura E. |last2=Japas |first2=María S. |date=2009 |title=The Choiyoi volcanic province at 34°S–36°S (San Rafael, Mendoza, Argentina): Implications for the Late Palaeozoic evolution of the southwestern margin of Gondwana |url=https://www.researchgate.net/publication/241406241 |journal=Tectonophysics |volume=473 |issue= 3–4|pages=283–299 |doi= 10.1016/j.tecto.2009.02.046|bibcode=2009Tectp.473..283K |access-date=5 January 2016|hdl=11336/75328 |hdl-access=free }} The batholith is emplaced amidst metamorphic rocks belonging to a Paleozoic accretionary complex. The northern parts are of the batholith are themselves intruded by Jurassic gabbros.

Rocks of the batholith belong to the calc-alkaline magma series.{{cite book |last1=Hervé |first1=F.|last2=Faundez |first2=V. |last3=Calderón |first3=M. |last4=Massonne |first4=H.-J. |last5=Willner |first5=A.P. |author-link=Francisco Hervé |editor-last1=Moreno |editor-first1=Teresa|editor-last2=Gibbons |editor-first2=Wes |title=The Geology of Chile |publisher=Geological Society of London |date=2007 |pages=7–20 |chapter=Metamorphic and plutonic basement complexes }}