Lanalhue Fault

Lanalhue Fault is a fault once active in the Paleozoic located in south-central Chile that cuts through Cordillera de Nahuelbuta. The fault takes name from Lanalhue Lake which overlies part of fault. The lanalhue fault makes up a major lithological boundary in the Chilean Coast Range to which Cordillera de Nahuelbuta belongs. From Valparaíso Region to Lanalhue Fault Carboniferous-Permian granitoids makes upp a large part of the bedrock 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 formed by at least since the Paleozoic along the subduction zone at South Americas western margin.

It is speculated that the inferred Gastre Fault Zone, that aligns Villarrica, Quetrupillán and Lanín volcanoes, is a continuation of the fault in the Andes. Lanalhue Fault has a northwest to southwest orientation.