Articles | Volume 5, issue 3
Earth Surf. Dynam., 5, 479–492, 2017
https://doi.org/10.5194/esurf-5-479-2017
Earth Surf. Dynam., 5, 479–492, 2017
https://doi.org/10.5194/esurf-5-479-2017

Research article 24 Aug 2017

Research article | 24 Aug 2017

Quantifying the controls on potential soil production rates: a case study of the San Gabriel Mountains, California

Jon D. Pelletier Jon D. Pelletier
  • Department of Geosciences, University of Arizona, Gould-Simpson Building, 1040 East Fourth Street, Tucson, Arizona 85721-0077, USA

Abstract. The potential soil production rate, i.e., the upper limit at which bedrock can be converted into transportable material, limits how fast erosion can occur in mountain ranges in the absence of widespread landsliding in bedrock or intact regolith. Traditionally, the potential soil production rate has been considered to be solely dependent on climate and rock characteristics. Data from the San Gabriel Mountains of California, however, suggest that topographic steepness may also influence potential soil production rates. In this paper I test the hypothesis that topographically induced stress opening of preexisting fractures in the bedrock or intact regolith beneath hillslopes of the San Gabriel Mountains increases potential soil production rates in steep portions of the range. A mathematical model for this process predicts a relationship between potential soil production rates and average slope consistent with published data. Once the effects of average slope are accounted for, a small subset of the data suggests that cold temperatures may limit soil production rates at the highest elevations of the range due to the influence of temperature on vegetation growth. These results suggest that climate and rock characteristics may be the sole controls on potential soil production rates as traditionally assumed but that the porosity of bedrock or intact regolith may evolve with topographic steepness in a way that enhances the persistence of soil cover in compressive-stress environments. I develop an empirical equation that relates potential soil production rates in the San Gabriel Mountains to the average slope and a climatic index that accounts for temperature limitations on soil production rates at high elevations. Assuming a balance between soil production and erosion rates on the hillslope scale, I illustrate the interrelationships among potential soil production rates, soil thickness, erosion rates, and topographic steepness that result from the feedbacks among geomorphic, geophysical, and pedogenic processes in the San Gabriel Mountains.

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The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.
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Dynam., 5, 479&ndash;492, 2017</div>\n                    <div class=\"citation-doi\">https://doi.org/10.5194/esurf-5-479-2017</div>\n                    <div class=\"citation-copyright\">&copy; Author(s) 2017. Thi", "lass=\"citation-header\">\n                    <div class=\"citation\">Earth Surf. Dynam., 5, 479&ndash;492, 2017</div>\n                    <div class=\"citation-doi\">https://doi.org/10.5194/esurf-5-479-2017</div>\n                    <div class=\"citation-copyright\">&copy; Author(s) 2017. This work is distributed under <br class=\"hide-on-mobile hide-on-tablet\" />the Creative Commons Attribution 3.0 License.</div>\n                        <div class=\"citation-copyright-icon\">\n                            <a target=\"_blank\" href=\"https://creativecommons.org/licenses/by/3.0/\" rel=\"license\" class=\"licence-icon\"> <img src=\"https://www.earth-surface-dynamics.net/licenceIcon_12.png\"></a></div>\n                </div>\n            </div>        </div>\n        <div class=\"grid-55 hide-on-tablet hide-on-mobile grid-parent\">\n                <div class=\"text-right articleBackLink\">\n                    <a href=\"https://esurf.copernicus.org/\">Articles</a> | <a href=\"https://esurf.copernicus.org/articles/5/issue3.html\">Volume 5, issue 3</a>\n                </div>\n                <div class=\"tab co-angel-left hide-o"], "cc_re__cc_re__cc_by_4_0": ["g\" alt=\"\" style=\"width: 1784px; height: 330px;\" /></a></span>\r\n</div>\n\n                    </div>\n\n                </div>\n\n            </div>\n\n        </div>\n\n    </div>\n\n    <div class=\"links pb-4 pt-4\">\n\n        <div class=\"container\">\n\n            <div class=\"row align-items-center\">\n\n                <div class=\"col-12 col-xl-auto mt-3\">\n\n                    <div class=\"row align-items-start align-items-lg-center\">\n\n                        <div class=\"d-none d-md-block col-md-auto pr-2 pt-1\"><a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\"><img src=\"https://www.earth-surface-dynamics.net/ci_refresh_graphic_cc_by_footer_logo.jpg\" cofileid=\"14271\" alt=\"\"></a></div>\n\n                        <div class=\"col-12 col-md mb-3 mb-md-0 pl-md-0 text-center text-md-left\">All site content, except where otherwise noted, is licensed under the <a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\">Creative Commons Attribution 4.0 License</a>.</div>\n\n                        <div class=\"d-md-none col-12 text-center\"><a href=\"https:/", "div class=\"row align-items-start align-items-lg-center\">\n\n                        <div class=\"d-none d-md-block col-md-auto pr-2 pt-1\"><a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\"><img src=\"https://www.earth-surface-dynamics.net/ci_refresh_graphic_cc_by_footer_logo.jpg\" cofileid=\"14271\" alt=\"\"></a></div>\n\n                        <div class=\"col-12 col-md mb-3 mb-md-0 pl-md-0 text-center text-md-left\">All site content, except where otherwise noted, is licensed under the <a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\">Creative Commons Attribution 4.0 License</a>.</div>\n\n                        <div class=\"d-md-none col-12 text-center\"><a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\"><img src=\"https://www.earth-surface-dynamics.net/ci_refresh_graphic_cc_by_footer_logo.jpg\" cofileid=\"14271\" alt=\"\"></a></div>\n\n                    </div>\n\n                </div>\n\n                <div class=\"col-12 text-center text-md-left col-lg-auto mt-3\">\n\n                    <div class=\"row align-items-cen", "target=\"_blank\"><img src=\"https://www.earth-surface-dynamics.net/ci_refresh_graphic_cc_by_footer_logo.jpg\" cofileid=\"14271\" alt=\"\"></a></div>\n\n                        <div class=\"col-12 col-md mb-3 mb-md-0 pl-md-0 text-center text-md-left\">All site content, except where otherwise noted, is licensed under the <a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\">Creative Commons Attribution 4.0 License</a>.</div>\n\n                        <div class=\"d-md-none col-12 text-center\"><a href=\"https://creativecommons.org/licenses/by/4.0/\" target=\"_blank\"><img src=\"https://www.earth-surface-dynamics.net/ci_refresh_graphic_cc_by_footer_logo.jpg\" cofileid=\"14271\" alt=\"\"></a></div>\n\n                    </div>\n\n                </div>\n\n                <div class=\"col-12 text-center text-md-left col-lg-auto mt-3\">\n\n                    <div class=\"row align-items-center\">\n\n                        <div class=\"col d-md-none px-0\"></div>\n\n                        <div class=\"col-auto pr-1\"><a href=\"https://www.earth-surface-dynamics.net/about/contact.html\">"], "copyright__copyright__copyright": ["The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.", "The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.", "The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.", "The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.", "The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way.", "The rate at which bedrock can be converted into transportable material is a fundamental control on the topographic evolution of mountain ranges. Using the San Gabriel Mountains, California, as an example, in this paper I demonstrate that this rate depends on topographic slope in mountain ranges with large compressive stresses via the influence of topographically induced stresses on fractures. Bedrock and climate both control this rate, but topography influences bedrock in an interesting new way."]}