Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ghiglione, M. C. Articles by Cristallini, E. O. Search for Related Content GeoRef GeoRef Citation

Have the southernmost Andes been curved since Late Cretaceous time? An analog test for the Patagonian Orocline

¹ Laboratorio de Tectónica Andina, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina, and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avda. Rivadavia 1917, CP C1033AAJ, Ciudad. de Buenos Aires, Argentina
² Laboratorio de Modelado Geológico (LaMoGe), Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina, and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avda. Rivadavia 1917, CP C1033AAJ , Ciudad. de Buenos Aires, Argentina

The kinematic evolution of the enigmatic arc-shaped southernmost Andes of Patagonia and Tierra del Fuego has been a subject of debate for most of the past century. We compared the results from analog sandbox experiments with the tectonic evolution and actual configuration of the mountain chain in order to elucidate whether oroclinal bending took place during the Tertiary, or if the southernmost Andes have been a curved orogen since at least Late Cretaceous time. Experiments simulating oroclinal rotation produced strong along-strike variations in shortening and failed to account for structural data compiled from the Fuegian Andes. Results from experiments simulating an L-shaped, concave-to-foreland indenter were in agreement with the known Tertiary structural evolution of the southernmost Andes. The diachronicity of principal shortening events previously recognized in Patagonia and Tierra del Fuego could only be reproduced by moving the indenter in two successive orthogonal directions: first approximately northward to form the Fuegian fold-and-thrust belt, and then approximately eastward to propagate thrusting in the Patagonian Andes. This two-phase evolution is consistent with a recorded change in the convergence direction of the Farallon-Nazca plate that occurred at ca. 27 Ma.

Key Words: oroclines • sand analog experiments • arcuate structures • Patagonian Andes • Tierra del Fuego

This article has been cited by other articles:

				M. C. Ghiglione, D. Yagupsky, M. Ghidella, and V. A. Ramos Continental stretching preceding the opening of the Drake Passage: Evidence from Tierra del Fuego Geology, August 1, 2008; 36(8): 643 - 646. [Abstract] [Full Text] [PDF]