Paleogene building of the Bolivian Orocline: Tectonic restoration of the central Andes in 2-D map viewReportar como inadecuado




Paleogene building of the Bolivian Orocline: Tectonic restoration of the central Andes in 2-D map view - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1 Departamento de Geologıa 2 GR - Géosciences Rennes 3 LMTG - Laboratoire des Mécanismes et Transfert en Géologie

Abstract : Using available information on the magnitude and age of tectonic shortening, as well as paleomagnetically determined tectonic rotations, we have run a series of 2-D map view restorations of the central Andes. Neogene shortening in the foreland belt induced only slight orogenic curvature of the central Andes. The constraints on the ages of the large observed fore-arc rotations average of 37° counterclockwise in southern Peru and 29° clockwise in northern Chile indicate that the Bolivian Orocline formed during the Eocene-Oligocene as a consequence of differential shortening focused in the Eastern Cordillera. To minimize local block rotations along the fore arc, the restoration that best fits the central Andean rotation pattern requires about 400 km of total Paleogene plus Neogene shortening near the Arica bend. This value corresponds to the upper bound of estimates of maximum horizontal shortening for the central Andes. Along-strike variations in horizontal shortening in the back arc induced bending of the continental margin, block rotations with fore-arc along-strike extension, and-or orogen-parallel transport of upper crustal material toward the symmetry axis of the orocline.

Keywords : Paleogene tectonics paleomagnetism central Andes Bolivian Orocline





Autor: César Arriagada - Pierrick Roperch - Constantino Mpodozis - Peter Cobbold -

Fuente: https://hal.archives-ouvertes.fr/



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