The Magallanes–Fagnano Fault () is a continental

transform fault A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subductio ...

. The fault marks a

transform boundary A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal. It ends abruptly where it connects to another plate boundary, either another transform, a spreading ridge, or a subductio ...

between the

Scotia Plate The Scotia Plate () is a tectonic plate on the edge of the South Atlantic and Southern oceans. Thought to have formed during the early Eocene with the opening of the Drake Passage that separates South America from Antarctica, it is a minor pla ...

and the

South American Plate The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mid-A ...

, cutting across

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called ''sial'' be ...

. It runs under the

Strait of Magellan The Strait of Magellan (), also called the Straits of Magellan, is a navigable sea route in southern Chile separating mainland South America to the north and Tierra del Fuego to the south. The strait is considered the most important natural pass ...

's western arm,

Almirantazgo Sound Almirantazgo Fjord ( es, Fiordo Almirantazgo), also known as Almirantazgo Sound ( es, Seno Almirantazgo) or Admiralty Sound, is a Chilean fjord located in the far south of the country at .Earth Info, ''earth-info.nga.mil'' webpage: . The fjor ...

and

Fagnano Lake Fagnano Lake ( es, Lago Fagnano), also called ''Lake Cami'' (), is a lake located on the main island of the Tierra del Fuego archipelago, and shared by Argentina and Chile. The 645 km2 lake runs east–west for about 98 kilometres, of which ...

. It has been suggested that the Magallanes-Fagnano Fault is a reactivated suture of pre-

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

age separating the

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

of two

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own ...

References

Seismic faults of Argentina Seismic faults of Chile Geology of Magallanes Region Strike-slip faults Suture zones Geology of Tierra del Fuego {{MagellanAntarctic-geo-stub