Tierra del Fuego

Research Objective

This project involves using unique exposures of the deep crust in the southernmost Andes to test the ways in which pre-orogenic conditions arising from extension and rifting can influence orogenic growth during subsequent contraction. It combines expertise in the fields of structural geology, metamorphic petrology, U-Pb geochronology (zircon, titanite, monazite), and thermochronology (40Ar-39Ar, K-Ar, fission track and (U-Th)/He) to determine the ages of deformation and the tectonic/thermal evolution of the southernmost Andes.

Collaborations

Stuart Thomson, University of Arizona

Francisco Hervé, University of Chile

Constantino Mpodozis, Antofagasta Minerals, Chile

Geoff Clarke, University of Sydney

Mark Fanning, ANU

Suzanne Baldwin, Syracuse University

Lisandro Rojas, SIPETROL, Chile

Student Researchers

Javier Álvarez (Univ. of Chile), Paul Betka (Univ. of Texas and Univ. of Vermont), Hernán Bobadilla (Univ. of Chile), Kayla Maloney, (Univ. of Sydney), Janelle McAtamney (Univ. of Vermont), Fernando Poblete (Univ. of Chile), Shane Snyder (Univ. of Vermont).

Selected Publications

(download by clicking on first author)

Klepeis, K., P. Betka, G. Clarke, M. Fanning, F. Hervé, L. Rojas, C. Mpodozis, and S. Thomson (2010), Continental underthrusting and obduction during the Cretaceous closure of the Rocas Verdes rift basin, Cordillera Darwin, Patagonian Andes, Tectonics, 29, TC3014, doi: 10.1029/2009TC002610.

Hervé, F., C.M. Fanning, R. J. Pankhurst, C. Mpodozis, K. Klepeis, M. Calderón, and S.N. Thomson (2010), Detrital zircon SHRIMP U-Pb age study of the Cordillera Darwin Metamorphic Complex of Tierra del Fuego: sedimentary sources and implications for the evolution of the Pacific margin of Gondwana, J. Geol. Soc., London, 167, 555-568.

McAtamney, J. (2010), Orogenesis reflected in a Late Cretaceous back arc basin inversion in the southernmost Andes (54.5ºS): new provenance data from Bahía Brookes and Seno Otway southern Patagonia, Chile, Masters of Science thesis, University of Vermont, Burlington, Vermont, 124 pp.

Maloney, K.T., G.L. Clarke, K.A. Klepeis, C.M. Fanning, and W. Wang (2011), Crustal growth during back-arc closure: Cretaceous exhumation history of Cordillera Darwin, southern Patagonia, J. Metamorphic Geology, 29(4), doi:10.1111/j.1525-1314.2011.00934.x.

McAtamney, J., K. Klepeis, C. Mehrtens, S. Thomson, P. Betka, L. Rojas, and S. Snyder (2011), Along-strike variability of back-arc basin collapse and the initiation of sedimentation in the Magallanes foreland basin, southernmost Andes (53–54.5°S), Tectonics, 30, TC5001, doi:10.1029/2010TC002826.

Supported by NSF