The Gastre Fault Zone (GFZ) is a NW-SE striking dextral Jurassic Gastre Fault System (cf. Rapela & Pankhurst, 1992) in Central Patagonia, Argentina.^[1]

From a tentative correlation of the fault zone with the similarly NW-SE trend, it was termed ‘Gastre Fault Zone’ or ‘Gastre-Purén Fault Zone’ to the Lanalhue Fault Zone in Chile by early works. However, in later works ^[2] it is shown that this correlation is incorrect. Since the lake ‘Lago Lanalhue’, is located on the fault trace and shows a NW-SE-elongated shape, ‘Lanalhue Fault Zone (LFZ)’ stands as appropriate name for the here discussed fault zone. The Mocha-Villarrica Fault Zone is the NW-SE trending fault responsible for the alignment of Villarrica, Quetrupillán and Lanín volcanoes.^[3]