Osorno–Llanquihue Basin

40°42′44″S 73°06′33″W / 40.712124°S 73.109218°W / -40.712124; -73.109218EtymologyOsorno and Llanquihue LakeLocationSouthwestern South AmericaCountry ChileState(s)Los Ríos Region
Los Lagos RegionCharacteristicsOn/OffshoreSouthern tip is offshoreBoundariesChilean Coast Range (W)
Andes (E)HydrologySea(s)Eastern Pacific OceanRiver(s)Bueno, Negro, Pilmaiquén, Rahue, DamasLake(s)Llanquihue, Laguna Las Ortigas and the westernmost portions of Rupanco, Puyehue and RancoGeologyBasin typeForearc basinOrogenyAndeanAgeOligocene-PleistoceneField(s)Chilean coal

The Osorno–Llanquihue Basin (Spanish: Cuenca Osorno-Llanquihue) is a sedimentary basin located in south-central Chile in the forearc region of the Andes. From north to south the basin spans and area from Catamutún to Reloncaví Sound (40–42° S).^[1] The deepest part of the basin lie to the east.^[2] The lower levels of the basin are occupied by coal-bearing Cheuquemó Formation among other units while the Miocene-aged marine Santo Domingo Formation makes up much of the upper stratigraphy.^[2] The uppermost levels are made of sediments of Quaternary age of glacial, glaci-fluvial, glaci-lacustrine and volcanic character.^[3] The thickness of Quaternary sediments is greater to the south reaching almost 1,300 m (4,300 ft) in Puerto Montt.^[3] Sediments in the western part of the basin are roughly estimated to have reached 70 °C (158 °F) during burial and diagenesis.^[4]

Bibliography

• Elgueta, Sara; McDonough, Michael; Le Roux, Jacobus; Urqueta, Esteban & Duhart, Paul (2000), Estratigrafía y sedimentología de las cuencas Terciarias de la Región de Los Lagos (39-41°30'S) (in Spanish), Santiago, Chile: Servicio Nacional de Geología y Minería, ISSN 0020-3939