Sierra Baguales

The mountain range contains a series of cirques formed by glaciers.^[2] Many cirques developed in the Pleistocene Epoch from isolated glaciers that existed separedly from ice sheets further west.^[2] The rocks of Sierra Baguales belong to various formations of Magallanes Basin.^[3] These rocks contain fossils of plants, mammals and marine invertebrates.^[3]

From top to bottom the following formations make up Sierra Baguales:^[3]

• Santa Cruz Formation, sedimentary rocks belonging to a non-marine succession and hosting many vertebrate fossils^[4]
• Estancia 25 de Mayo Formation, a succession of fossil-bearing sedimentary rocks that date to the Early Miocene. Sediments were deposited in a marine environment.
• La Cumbre Formation, an olivine-bearing gabbro sill
• Río Leona Formation, a succession of non-marine fossils, some of which contain Nothofagus fossils
• Bandurrías Formation, an olivine-bearing gabbro sill
• Loreto Formation, sedimentary rocks variously assigned a Late Eocene to Early Miocene age. Contains fossil shark teeth.

On the eastern slopes of Sierra Baguales various lithic artifacts have been found.^[1] Human occupation of eastern foothills begun no later than 4,500 years before present.^[1]

• Bostelmann, J. Enrique; Le Roux, Jacobus P.; Vásquez, Ana; Gutiérrez, Néstor M.; Oyarzún, José Luis; Carreño, Catalina; Torres, Teresa; Otero, Rodrigo; Llanos, C. Mark Fanning, Francisco Hervé, Andrea (2013), "Burdigalian deposits of the Santa Cruz Formation in the Sierra Baguales, Austral (Magallanes) Basin: Age, depositional environment and vertebrate fossils" (PDF), Andean Geology, 40: 458–489, retrieved 2019-02-28{{citation}}: CS1 maint: multiple names: authors list (link)