Skip to Main Content
Book Chapter

The Miocene Arizaro Basin, central Andean hinterland: Response to partial lithosphere removal?

By
P.G. DeCelles
P.G. DeCelles
Department of Geosciences, University of Arizona, Tucson, Arizona 85716, USA
Search for other works by this author on:
B. Carrapa
B. Carrapa
Department of Geosciences, University of Arizona, Tucson, Arizona 85716, USA
Search for other works by this author on:
B.K. Horton
B.K. Horton
Institute for Geophysics and Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78712, USA
Search for other works by this author on:
J. McNabb
J. McNabb
Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA
Search for other works by this author on:
G.E. Gehrels
G.E. Gehrels
Department of Geosciences, University of Arizona, Tucson, Arizona 85716, USA
Search for other works by this author on:
J. Boyd
J. Boyd
Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82070, USA
Search for other works by this author on:
Published:
January 01, 2015

The Arizaro Basin in northwestern Argentina sits today in the western Puna Plateau at elevations of 3800–4200 m along the eastern flank of the Miocene to modern magmatic arc. The basin is roughly circular in plan view and ~100 km in diameter, and it was filled during Miocene time (ca. 21–9 Ma) by >3.5 km of eolian, alluvial, fluvial, and lacustrine sediment in addition to ash-fall tuffs from the Andean magmatic arc. The basin fill was subsequently shortened in its central part, and it has been uplifted and topographically inverted. The Arizaro Basin is not obviously related to known faults, nor does it exhibit a peripheral belt of coarse-grained sedimentary rocks derived from flanking topographically higher regions. Sandstone modal framework compositions are arkosic, but not as rich in volcanic lithic fragments as typical intra-arc basins. Detrital zircon U-Pb age spectra implicate source terranes in locally exposed Ordovician granitoid rocks, more distal Upper Paleozoic–Mesozoic arc terranes in western Argentina and possibly northern Chile, and the local Miocene magmatic arc. Depositional-age zircons are present in most of the sandstones analyzed for detrital zircon U-Pb geochronology, and zircon U-Pb ages from volcanic tuff layers provide independent chronological control. The tectonic component of subsidence initiated at low rates, accelerated to ~0.6 mm/yr during the medial stage of basin development, and tapered off to zero as the basin began to shorten internally and experience topographic inversion after ca. 10 Ma. Together, the data presented here suggest that the Arizaro Basin could have developed in response to the formation and gravitational foundering of a dense Rayleigh-Taylor–type instability in the lower crust and/or mantle lithosphere. Insofar as hinterland basins of uncertain tectonic affinity are widespread in the high central Andes, the model developed here may be relevant for other regions of enigmatic subsidence and sediment accumulation in the Andes and other cordilleran hinterland settings.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

GSA Memoirs

Geodynamics of a Cordilleran Orogenic System: The Central Andes of Argentina and Northern Chile

Peter G. DeCelles
Peter G. DeCelles
Department of Geosciences, University of Arizona, Tucson, Arizona, USA
Search for other works by this author on:
Mihai N. Ducea
Mihai N. Ducea
Department of Geosciences, University of Arizona, Tucson, Arizona, USA, and Universitatea Bucuresti, Facultatea de Geologie Geofizica, Strada N. Balcescu Nr 1, Bucuresti, Romania
Search for other works by this author on:
Barbara Carrapa
Barbara Carrapa
Department of Geosciences, University of Arizona, Tucson, Arizona, USA
Search for other works by this author on:
Paul A. Kapp
Paul A. Kapp
Department of Geosciences, University of Arizona, Tucson, Arizona, USA
Search for other works by this author on:
Geological Society of America
Volume
212
ISBN print:
9780813712123
Publication date:
January 01, 2015

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

Related Articles
Related Book Content
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal