Osorno–Llanquihue Basin
| Osorno–Llanquihue Basin | |
|---|---|
| Cuenca de Osorno-Llanquihue | |
SRTM map of the topography of the northern part of Osorno–Llanquihue Basin. The basin does largely correspond with the topographic low of the Chilean Central Valley. | |
| Coordinates | 40°42′44″S 73°06′33″W / 40.712124°S 73.109218°W |
| Etymology | Osorno and Llanquihue Lake |
| Location | Southwestern South America |
| Country | Chile |
| State(s) | Los Ríos Region Los Lagos Region |
| Characteristics | |
| On/Offshore | Southern tip is offshore |
| Boundaries | Chilean Coast Range (W) Andes (E) |
| Hydrology | |
| Sea(s) | Eastern Pacific Ocean |
| River(s) | Bueno, Negro, Pilmaiquén, Rahue, Damas |
| Lake(s) | Llanquihue, Laguna Las Ortigas and the westernmost portions of Rupanco, Puyehue and Ranco |
| Geology | |
| Basin type | Forearc basin |
| Orogeny | Andean |
| Age | Oligocene-Pleistocene |
| Field(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). The deepest part of the basin lie to the east. 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. The uppermost levels are made of sediments of Quaternary age of glacial, glaci-fluvial, glaci-lacustrine and volcanic character. The thickness of Quaternary sediments is greater to the south reaching almost 1,300 m (4,300 ft) in Puerto Montt. Sediments in the western part of the basin are roughly estimated to have reached 70 °C (158 °F) during burial and diagenesis.