Dec 5, 2017 - prograding submarine slope system and consists dominantly ...... type quantification method (e.g., Pevear, 1992; ...... .1029 /JB091iB01p00471 .
Timing of Patagonian fold-and-thrust belt formation in southern Chile
Timing and thermal evolution of fold-and-thrust belt formation in the Ultima Esperanza District, 51°S Chile: Constraints from K-Ar dating and illite characterization Annette Süssenberger1,†, Susanne T. Schmidt1,†, Klaus Wemmer 2,†, Lukas P. Baumgartner 3,†, and Bernard Grobéty4,† Department of Earth Sciences, University of Geneva, 13 Rue des Maraîchers, 1205 Geneva, Switzerland Geoscience Center, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany 3 Institute of Earth Sciences, University of Lausanne, 1015 Lausanne, Switzerland 4 Department of Geosciences, University of Fribourg, Chemin du Musée, 1700 Fribourg, Switzerland 1 2
ABSTRACT K-Ar dating on synkinematically formed illite in low-grade metamorphic pelites was used to set new time constraints on the development of the Patagonian retroarc fold-andthrust belt caused by the subduction of the Antarctic plate beneath the South American plate. The combined use of illite crystallinity (Kübler index), polytype quantification, and K-Ar dating of illite fractions (
