Magallanes Basin

Magallanes or Austral Basin
Magallanes or Austral Basin
Cuenca de Magallanes, Cuenca Austral
Coordinates	53°00′S 69°30′W
Etymology	Strait of Magellan; Austral = "south"
Location	Southern South America
Region	Patagonia
Country	Argentina; Chile
State(s)	Santa Cruz Province; Aysén & Magallanes Regions
Cities	Punta Arenas; Ushuaia
Characteristics
On/Offshore	Both
Boundaries	Andes, Río Chico-Dungeness High
Part of	Andean foreland basins
Area	170,000–200,000 km2 (66,000–77,000 sq mi)
Hydrology
Sea(s)	Southern Atlantic Ocean
River(s)	Shehuén River
Lake(s)	Viedma, Cardiel, Argentino, Pueyrredón, Fontana
Geology
Basin type	Foreland basin
Orogeny	Andean
Age	Jurassic-Holocene
Stratigraphy	Stratigraphy
Field(s)	Chilean coal

The Magallanes Basin^[A] or Austral Basin^[B] is a major sedimentary basin in southern Patagonia. The basin covers a surface of about 170,000 to 200,000 square kilometres (66,000 to 77,000 sq mi) and has a NNW-SSE oriented shape.^[1]^[2] The basin is bounded to the west by the Andes mountains and is separated from the Malvinas Basin to the east by the Río Chico-Dungeness High.^[1] The basin evolved from being an extensional back-arc basin in the Mesozoic to being a compressional foreland basin in the Cenozoic.^[3] Rocks within the basin are Jurassic in age and include the Cerro Toro Formation.^[4] Three ages of the SALMA classification are defined in the basin; the Early Miocene Santacrucian from the Santa Cruz Formation and Friasian from the Río Frías Formation and the Pleistocene Ensenadan from the La Ensenada Formation.

Quick facts Coordinates, Etymology ...

The Magallanes Basin contains most of Chile's coal reserves dwarfing those found in the Arauco Basin or around Valdivia (e.g. Catamutún, Mulpún). Its coals are lignitic to sub-bituminous.^[5]

Stratigraphy