Linking orography, climate, and exhumation across the central Andes
2012-09-19

Research Article| December 01, 2012 Linking orography, climate, and exhumation across the central Andes Jason B. Barnes; Jason B. Barnes 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA Search for other works by this author on: GSW Google Scholar Todd A. Ehlers; Todd A. Ehlers 2Department of Geosciences, University of Tübingen, Tübingen 72076, Germany Search for other works by this author on: GSW Google Scholar Nadja Insel; Nadja Insel 3Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637, USA Search for other works by this author on: GSW Google Scholar Nadine McQuarrie; Nadine McQuarrie 4Department of Geology and Planetary Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA Search for other works by this author on: GSW Google Scholar Christopher J. Poulsen Christopher J. Poulsen 5Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Jason B. Barnes 1Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA Todd A. Ehlers 2Department of Geosciences, University of Tübingen, Tübingen 72076, Germany Nadja Insel 3Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637, USA Nadine McQuarrie 4Department of Geology and Planetary Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA Christopher J. Poulsen 5Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005, USA Publisher: Geological Society of America Received: 23 Jan 2012 Revision Received: 25 May 2012 Accepted: 14 Jun 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (12): 1135–1138. https://doi.org/10.1130/G33229.1 Article history Received: 23 Jan 2012 Revision Received: 25 May 2012 Accepted: 14 Jun 2012 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jason B. Barnes, Todd A. Ehlers, Nadja Insel, Nadine McQuarrie, Christopher J. Poulsen; Linking orography, climate, and exhumation across the central Andes. Geology 2012;; 40 (12): 1135–1138. doi: https://doi.org/10.1130/G33229.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Quantifying interactions between uplift, climate, deformation, and exhumation remains difficult, in many cases due to a paucity of data relevant to all processes. We synthesize new and existing data to understand the orogen-scale orographic changes across the central Andes, Bolivia. We use a regional climate model and geo-thermochronologic data to identify the correlations between changes in precipitation due to surface uplift and spatiotemporal patterns of deformation and erosional exhumation. Mean orographic rainfall patterns do not reach near present-day gradients and values until the topography grows to >75% modern elevations. New fission-track data near the orocline apex indicate that rapid exhumation moved eastward, beginning in the Eastern Cordillera ca. 50–15 Ma, the Interandean zone ca. 18–6 Ma, and in the Subandes ca. 7–3 Ma. Throughout Bolivia, exhumation is consistent with deformation until ca. 15–11 Ma, after which the pattern corresponds better with the increased rainfall toward modern values. These linked observations suggest that ca. 15–11 Ma, regional elevations reached threshold values (>75% modern) necessary to generate near present-day, enhanced rainfall gradients. These gradients have resulted in variable exhumation implied by the structural level of rocks exposed across the thrust belt and confirmed by fission tracks in apatite. The main insight is that the climate-induced Middle Miocene–recent exhumation varies over scales of a few hundred kilometers across Bolivia and implies that high mean rainfall (>∼3 m/yr) and long time scales (∼10 m.y.) may be necessary for climate to induce orographically driven exhumation patterns recorded by fission tracks. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.