structural:summarization, quality:corruption, structural:scholar_edition, information:filtering
Geology

The geology of the archipelago is influenced by the effects of the Andean orogeny and the repeated Pleistocene glaciations. The geology of the island can be divided into large east–west-oriented units. The southwestern islands of the archipelago, including Cape Horn, are part of the South Patagonian Batholith, while the Cordillera Darwin and the area around the Beagle Channel form the principal mountain range hosting the highest mountains. The Magallanes fold and thrust belt extends north of Almirantazgo Fjord and Fagnano Lake, and north of this lies the Magallanes foreland, an old sedimentary basin that hosts hydrocarbon reserves. Orthogneiss dated at 525 million years is known to underlie some of the oil wells in northern Tierra del Fuego.

The Magallanes–Fagnano Fault, a sinistral strike slip fault crosses the southern part of the main island from west to east. It is an active fault, located inside and parallel to the Fuegian fold and thrust belt, and marks the boundary between a southern belt of Paleozoic meta sediments and a northern Mesozoic belt of sedimentary sequences. Fagnano Lake occupies a glacier-carved depression in a pull-apart basin that has developed along the Magallanes-Fagnano Fault zone.

Podzols and inceptisols occur beneath Nothofagus betuloides forests in Tierra del Fuego.