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Stable isotope evidence for multiple pulses of rapid surface uplift in the Central Andes, Bolivia

Leier, Andrew and McQuarrie, Nadine and Garzione, Carmala and Eiler, John (2013) Stable isotope evidence for multiple pulses of rapid surface uplift in the Central Andes, Bolivia. Earth and Planetary Science Letters, 371 . pp. 49-58. ISSN 0012-821X. https://resolver.caltech.edu/CaltechAUTHORS:20130801-132321474

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Abstract

Paleoelevation histories from mountain belts like the Central Andes of Bolivia provide important constraints on the timing and geodynamic mechanisms associated with surface uplift. We present new oxygen and carbon isotope data (δ^(18)O, δ^(13)C, and Δ_(47)) from Oligocene–Miocene strata exposed in the Eastern Cordillera of the Bolivian Central Andes in order to reconstruct both the deformation and paleoelevation history of the region prior to late Miocene time. Paleosol carbonate in strata >24 Ma have δ^(18)O_c values between −5.7‰ and −9.7‰, and Δ_(47) values indicating paleotemperatures of 32–42 °C. Paleosol carbonate in strata ca. 17 Ma have δ^(18)O_c values between −11.6‰ and −13.8‰, and Δ47 values indicating paleotemperatures of 15–23 °C. These data, interpreted within the context of recent paleoclimate-topography models, suggest Oligocene–early Miocene (29–24 Ma) paleoelevations were between 0 and 1.5 km a.s.l., while middle Miocene (ca. 20–15 Ma) paleoelevations were ~2.5 km a.s.l. Oligocene and Miocene strata are relatively undeformed and overlap folded and faulted Paleozoic rocks in this portion of the Bolivian Eastern Cordillera, indicating much of the change in elevation occurred after upper crustal deformation. Collectively, data from the area record an initial period of upper crustal deformation and exhumation, a subsequent period of sediment deposition and overlap, and then an episode of surface uplift accompanied by negligible upper crustal deformation. The disconnect between the timing of upper crustal deformation and the timing of surface uplift requires geodynamic processes other than upper crustal thickening to explain the Oligocene–Miocene basin and elevation history in the Eastern Cordillera. We propose accommodation for Oligocene–Miocene strata was created in response to the formation and removal of negatively buoyant material in the lowermost crust and mantle lithosphere, and the subsequent increase in surface elevation between ca. 24 and 15 Ma resulted from its removal. Other locations in the Central Andes record similar geological histories over different time periods, suggesting spatial and temporal variation in the removal of lithospheric mantle. Documenting basin extent, age and elevation history provides important constraints on the size and timescale of the geodynamic processes that control surface uplift.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/j.epsl.2013.04.025DOIArticle
http://www.sciencedirect.com/science/article/pii/S0012821X13002136PublisherArticle
Additional Information:© 2013 Elsevier B.V. Received 7 September 2012. Received in revised form 3 April 2013. Accepted 19 April 2013. Editor: J. Lynch-Stieglitz. Available online 17 May 2013. Funding for this work has been provided by the National Science Foundation – Division of Earth Sciences, and the Natural Sciences and Engineering Research Council of Canada. We would like to thank P. Higgins and N. Kitchen, and M. Cosca. We would also like to thank S. Long, T. Cecil-Cockwell, and T. Dixon. Additional assistance was provided by S. Tawackoli, and C. Ossio. We thank B. McFadden for his guidance. Discussions with C. Poulson and J. Barnes and many others helped focus the manuscript. We thank three anonymous reviewers who edited a previous version. The manuscript was greatly improved by the comments and careful edits of two anonymous reviewers. We also thank editor J. Lynch-Stieglitz.
Funders:
Funding AgencyGrant Number
NSF Division of Earth SciencesUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Subject Keywords: oxygen isotope paleoaltimetry; clumped-isotope thermometry; paleoelevation; Andes; orogeny; surface uplift
Record Number:CaltechAUTHORS:20130801-132321474
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20130801-132321474
Official Citation:Andrew Leier, Nadine McQuarrie, Carmala Garzione, John Eiler, Stable isotope evidence for multiple pulses of rapid surface uplift in the Central Andes, Bolivia, Earth and Planetary Science Letters, Volumes 371–372, June 2013, Pages 49-58, ISSN 0012-821X, http://dx.doi.org/10.1016/j.epsl.2013.04.025. (http://www.sciencedirect.com/science/article/pii/S0012821X13002136)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:39711
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:01 Aug 2013 21:03
Last Modified:03 Oct 2019 05:10

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