Kinematic evolution of the Patagonian retroarc fold-and-thrust belt and Magallanes foreland basin, Chile and Argentina, 51 30'S

Abstract

Magallanes foreland basin, Chile and Argentina, 51°30 Kinematic evolution of the Patagonian retroarc fold-and-thrust belt and Email alerting services articles cite this article to receive free e-mail alerts when new www.gsapubs.org/cgi/alerts click Subscribe America Bulletin to subscribe to Geological Society of www.gsapubs.org/subscriptions/ click Permission request to contact GSA http://www.geosociety.org/pubs/copyrt.htm#gsa click official positions of the Society. citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect presentation of diverse opinions and positions by scientists worldwide, regardless of their race, includes a reference to the article's full citation. GSA provides this and other forums for the the abstracts only of their articles on their own or their organization's Web site providing the posting to further education and science. This file may not be posted to any Web site, but authors may post works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent their employment. Individual scientists are hereby granted permission, without fees or further

U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: its relationship with the evolution of the Austral Basin

“…The depocentre of the basin is located in the Última Esperanza Province in Chile, to the southwest of the study area. In this region, the presence of the deep-marine sediments of the Punta Barrosa Formation over the shelf-marine sediments of the Zapata Formation indicates the occurrence of a well-developed subaerial fold-and-thrust belt (Wilson, 1991;Fildani et al, 2003;Fildani and Hessler, 2005;Romans et al, 2010;2011;Fosdick et al, 2011). The Punta Barrosa Formation was dated on the basis of detrital zircon analysis, suggesting an age not older than 92±1 Ma (Fildani et al, 2003).…”

“…Likewise, Hervé et al (2007a) Basin. Stratigraphy and data on the Rocas Verdes Marginal Basin-Magallanes Basin taken from Fildani et al (2003) and Fosdick et al (2011). less probably, in the Eastern Metamorphic Complex (Hervé et al, 2007a, b), or else to the Subcordilleran Batholith (Rapela et al, 2005). The youngest inherited age event is approximately 157 Ma (Upper Jurassic), which is contemporary with the final stage of V3 volcanism (157-153 Ma) in Pankhurst et al (2000).…”

“…A change from regional extension to compression occurred in the mid-Cretaceous and produced a retroarc fold-thrust belt and linked foreland basin, known in Chile as Magallanes Basin (Biddle et al, 1986;Wilson, 1991;Fildani et al, 2003;Fildani and Hessler, 2005;Fosdick et al, 2011). The geological history of the Austral Basin in the study area is characterized by three main tectonic stages (Biddle et al, 1986;Robbiano et al, 1996;Ramos, 2002;Kraemer et al, 2002;Peroni et al, 2002;Rodríguez and Miller, 2005).…”

“…This fold-and-thrust belt is associated along its eastern margin with a foreland basin (Austral Foreland Basin). This compression process extended from the Upper Cretaceous to the Neogene (Ramos et al, 1982;Biddle et al, 1986;Wilson, 1991;Spalletti and Franzese, 2007;Fosdick et al, 2011).…”

“…The transition was dated by means of detrital zircons, and the age was estimated as being no older than 92±1 Ma (Fildani et al, 2003). Recently, Fosdick et al (2011) obtained new zircon U-Pb ages from an interbedded volcanic ash in the Zapata-Punta Barrosa transition, suggesting an age of 101±1 Ma. They indicated that the deformation at 51º30'S began ~100 Ma and progressed during six main stages .…”