Rocks containing upper amphibolite facies assemblages reflecting Mesozoic-Cenozoic metamorphism form the 5000 km2 core of the southernmost Andes in Cordillera Darwin (approximately 55¿S latitude). Results from mapping along a 50-km, continuous transect across the southernmost Andes on the main island of Tierra del Fuego show structural relationships between the Late Cretaceous to early Tertiary uplift of the metamorphic core in northern Cordillera Darwin and mid-Cretaceous to Paleogene shortening in the adjacent Magallanes foreland fold and thrust belt. New data indicate that pre-Late Jurassic basement schists exposed along the northeastern edge of Cordillera Darwin were uplifted along a discrete, brittle, continent-vergent thrust fault. This thrust overlies a series of thin-skinned thrusts and back thrusts that affect Mesozoic-Tertiary rocks of the Magallanes foreland basin. The thrust that uplifts basement schists is interpreted to have formed out of sequence with respect to the thin-skinned structures because it placed the schists over previously shortened Lower Cretaceous sedimentary strata of the Magallanes basin. The geometry of thrusts observed across the transect and their inferred sequence of deformation indicate a thick-skinned, contractional mechanism for uplift of the pre-Late Jurassic schists of northern Cordillera Darwin relative to the structural level of metamorphic basement in the Magallanes foreland. The relative time of out of sequence thrusting and basement uplift inferred from thrust geometries in this paper is consistent with the latest Cretaceous to early Tertiary episode of rapid exhumation and cooling of the metamorphic core of the southern Andean orogen determined in previous structural, metamorphic, and geochronological studies. ¿ American Geophysical Union 1994