info:eu-repo/semantics/publishedVersion
Tectonic Setting of the Tordillo Formation in the Aconcagua Fold-and-Thrust Belt
Fecha
2020Registro en:
Acevedo, Eliana Belén; Rosselot, Eduardo Agustín; Martos, Federico Exequiel; Fennell, Lucas Martín; Naipauer, Maximiliano; et al.; Tectonic Setting of the Tordillo Formation in the Aconcagua Fold-and-Thrust Belt; Springer; 2020; 159-174
978-3-030-29679-7
CONICET Digital
CONICET
Autor
Acevedo, Eliana Belén
Rosselot, Eduardo Agustín
Martos, Federico Exequiel
Fennell, Lucas Martín
Naipauer, Maximiliano
Folguera Telichevsky, Andres
Resumen
At the northwestern Mendoza province, the Mesozoic infill of the Neuquén Basin is tectonically repeated in the Aconcagua fold-and-thrust belt. Particularly, the Tordillo Formation (commonly associated with the Kimmeridgian) represents a local low stand period of sea level, with mainly alluvial and fluvial sediments. Toward the western sector of the belt, it interfingers with volcanic and volcaniclastic materials and presents a marked increase in the thickness. This unit was studied in two localities at the Blanco River valley, at the undeformed sector and over the second thrust that produces a second repetition of the Upper Jurassic and Lower Cretaceous sequences in the Aconcagua fold-and-thrust belt. This transect exposes facies variations and a significant increase in thickness to the west. Additionally, provenance analysis and paleocurrent directions indicate that the sediment supply was located to the E-SE, and that the underlying units were exhumed at the time of deposition of the Late Jurassic red beds. A consistent thickness increment of the Upper Jurassic deposits to the west through the Aconcagua fold-and-thrust belt suggests that sedimentation was controlled by NNW-directed structures. This is also supported by facies analyses that demonstrate high topographic breaks affecting a smooth westdipping fluvial ramp toward the volcanic arc. These features support an extensional setting for the deposition of the Tordillo Formation at the latitudes of the Aconcagua fold-and-thrust belt, as other authors have proposed for the Malargüe fold-and-thrust belt to the south. Plate tectonic reconstructions suggest trench rollback during this time previous to the westward migration of the South American plate, which is consistent with the back-arc extension proposed in the previous works.