Sebastián J. Cao

• Dr
• Centro Austral de Investigaciones Científicas

New mapping, detailed petrographic analyses and isotopic ages of the Jurassic21 Lower Cretaceous rocks of the Argentine Fuegian Andes allow us to organize the stratigraphic framework of the Rocas Verdes basin. Accordingly, we confirm a vast lithological heterogeneity associated with the Jurassic rifting that initiated this back-arc basin, including...

We report the field geology, petrography, geochemistry and geochronology data for two dyke swarms in the Fuegian Andes, with the aim of correlating them with known suites and of improving the knowledge on the magmatism of the Late Cretaceous rear-arc and its relation with ductile deformation. We also provide keys for correlation based on amphibole...

New structural data from the central belt of the Fuegian Andes (Argentina), allowed us to constrain the geometry of a previously interpreted Cenozoic duplex thrust system that connects forelandwards with the frontal thrustfold belt. This duplex developed between two main detachment horizons: a basal detachment between Jurassic rocks and pre-Jurassi...

Los Andes Fueguinos entre el lago Fagnano y el canal Beagle en el sector argentino de Tierra del Fuego (Fig. 1A) comprenden rocas metamórficas de muy bajo a bajo grado del Jurásico al Cretácico Inferior, con una amplia variedad de protolitos ígneos y sedimentarios pertenecientes a la cuenca Rocas Verdes (CRV). El cierre de la CRV inició durante el...

En el cinturón central de los Andes Fueguinos afloran zonas de cizalla dúctil, compuestas de milonitas, que constituyen una característica conspicua de las unidades más antiguas de este sector del orógeno. Estas milonitas han sido descritas con variado detalle por estructuralistas como Kranck (1932) y Bruhn (1979). Este último autor propuso un mode...

Although being one of the most efficient tools to constrain the stratigraphy of sedimentary basins, detrital zircon geochronology may present limitations under certain conditions, and isotopic ages should be treated with caution before assigning a depositional age. This is the case of depositional environments that lack coeval volcanism, where ther...

Tierra del Fuego is an island located at the southern tip of South America. It is one of the southernmost emerged lands on Earth, except for Antarctica. Its position is significant in terms of geologic environments both in the past and present times. During the Middle Jurassic, southern South America was exposed to regional extension and volcanism,...

New detailed structural data from the Fuegian Andes including new ages and cross-cutting relationships with intrusive rocks, as well as an appraisal of published structural data, support that this orogen evolved as a basement-involved thrust-fold belt after initial formation in an arc-continent collision scenario. New structural data from a deforme...

The structure of the Fuegian Andes central belt is characterized by a first phase of peak metamorphism and ductile deformation, followed by a brittle-ductile thrusting phase including juxtaposition of different (first phase) structural levels; both related to the closure and inversion of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The se...

Timing and structural relation between magmatic arc intrusives and the Fuegian thrust-fold belt at sierra Beauvoir. Intrusive rocks in the cretaceous slates of the internal Fuegian thrust-fold belt, allow us to constrain the age of deformation in the orogen. By studying cross-cut relationships between dikes and tectonic structures, we defined prede...

Structure and petrography of the Lapataia Formation, with implications for its stratigraphy. Fuegian Andes, Argentina. Since the geological observations made in the fuegian foothills by Kranck in 1932, several authors have debated whether the rocks of the Lapataia Formation belong to the Paleozoic basement or the Mesozoic volcanic-sedimentary infil...

A teaching activity for geosciences, with an emphasis on geology, in a new University (UNTDF, after its initials in Spanish) is conceived as a viable and low-cost endeavor to produce relevant geological information of public use. A student-teacher team work, focused on professionally supervised geologic mapping of the urban area as an approach to t...

Superposed structural fabrics in the easternmost Fuegian Andes reveal two distinct, non-coaxial deformation phases across the transition from the orogenic core to the thrust-fold belt. Each phase is characterized by different metamorphic conditions and consistently different orientations, which allow the structural correlation between the orogenic...