Lanalhue Fault is a fault once active in the Paleozoic

Paleozoic

The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...

 located in south-central Chile that cuts through Cordillera de Nahuelbuta. The fault takes name from Lanalhue Lake

Lanalhue Lake

Lanalhue Lake is a Chilean lake located in the Arauco Province of Biobío Region. The lake is placed in the Nahuelbuta Range above the Lanalhue Fault....

 which overlies part of fault. The lanalhue fault makes up a major lithological

Lithology

The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples or with low magnification microscopy, such as colour, texture, grain size, or composition. It may be either a detailed description of these characteristics or be a summary of...

 boundary in the Chilean Coast Range

Chilean Coast Range

The Chilean Coastal Range is a mountain range that runs from north to south along the Pacific coast of South America parallel to the Andean Mountains, extending from Morro de Arica in the north to Taitao Peninsula, where it ends at the Chile Triple Junction, in the south. The range has a strong...

 to which Cordillera de Nahuelbuta belongs. From Valparaíso Region

Valparaíso Region

The V Valparaíso Region is one of Chile's 15 first order administrative divisions.Valparaíso Region, 2006 With the country's third highest population of 1,539,852 million in 2002 and third smallest area of , the region is Chile's second most densely populated after the Santiago Metropolitan Region...

 to Lanalhue Fault Carboniferous

Carboniferous

The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

-Permian

Permian

The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

 granitoid

Granitoid

A granitoid or granitic rock is a variety of coarse grained plutonic rock similar to granite which mineralogically are composed predominately of feldspar and quartz. Examples of granitoid rocks include granite, quartz monzonite, quartz diorite, syenite, granodiorite and trondhjemite. Many are...

s makes upp a large part of the bedrock

Bedrock

In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...

 of the Chilean Coast Range. These igneous rocks was once part of a proto-Andean magmatic belt. South of Lanalhue Fault most of the Chilean Coast Range is an accretionary wedge

Accretionary wedge

An accretionary wedge or accretionary prism is formed from sediments that are accreted onto the non-subducting tectonic plate at a convergent plate boundary...

 formed by at least since the Paleozoic

Paleozoic

The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...

 along the subduction zone at South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

s western margin.

It is speculated that the inferred Gastre Fault Zone

Gastre Fault Zone

The Gastre Fault Zone is a NW-SE trending fault responsible for the alignment of Villarrica, Quetrupillán and Lanín volcanoes. The fault is believed to be a continuation of Lanalhue Fault which was active in late Paleozoic Era....

, that aligns Villarrica

Villarrica (volcano)

Villarrica is one of Chile's most active volcanoes, rising above the lake and town of the same name. The volcano is also known as Rucapillán, a Mapuche word meaning "House of the Pillán". It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain along the...

, Quetrupillán

Quetrupillán

Quetrupillán Volcano is a stratovolcano located in the Araucanía Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and...

 and Lanín

Lanín

Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its flag and its anthem. Although the date of its last eruption...

volcanoes, is a continuation of the fault in the Andes. Lanalhue Fault has a northwest to southwest orientation.