Picture of Jean Dixon

Assistant Professor of Earth Science

Contact Information

Office:   Traphagen Hall #216
Phone:   (406) 994-3342
Email:  jean.dixon@montana.edu

Earth Surface Processes Lab

Office Hours:

Tu, Th, 9:30-10:30 am, or by appointment

Affiliations:

Montana Institute on Ecosystems (IOE)

Education:

Ph.D. Dartmouth College, Earth Science, 2009
B.A. Carleton College, Geology 2000

Research Interests:

I am a geomorphologist interested in the chemical, physical and biological processes at Earth’s Surface that form soil from rock, transport soil and sediment, and sculpt the landsurface. My research uses geochemical tools such as cosmogenic radionuclides to quantify the rates and patterns of Earth surface processes. I couple geochemical analysis with field observations, digital terrain analysis and simple numerical models to understand the primary controls on the evolution of diverse landscapes and the sensitivity of the Earth’s soils and surface to external forces such as tectonics and climate.

My research follows several broad themes:

  • Thresholds for soil formation and weathering
  • Topographic signatures and rates of geomorphic processes
  • The role of external forcings such as climate, tectonics and humans in landscape evolution
  • Geochemical tracing of sediment generation and transport

Courses Taught

4 credits. Fall term. The study of the chemical and physical processes that sculpt Earth's surface.

4 credits. Spring term. Application of geologic principles to environmental problems. Topics imclude analysis of environmental issues such as earthquake disaster preparedness, landslides, land use, floods and human occupation, ground water withdrawal and contamination issues, volcanic and coastal hazards, and the response of landscapes and people to resource development (minerals/air/water/energy). Laboratories will be used to analyze and debate data relevant to environmental problems from a geologic perspective.

3 credits. Spring term. This class builds on its prerequisite course, ERTH 307: Geomorphology, by providing in-depth examination into advanced topics and methods in the field of geomorphology. Specific course topics change yearly, and may include (but are not limited to):
  • Tectonic Geomorphology
  • Earth’s ‘Critical Zone’: Where rocks, soil, water, air and life meet
  • Isotopic and quantitative tools in Geomorphology
3 credits. Summer term. A summer field course with application of field procedures and mapping techniques to a variety of geologic problems and exercises.
2 Credits. Fall term. This course is designed to develop a shared knowledge base and professional toolkit among entering graduate students in the Department of Earth Sciences. The course provides an introduction to contemporary research methods, tools, and professional development necessary for graduate study in Earth Sciences.

Graduate Students

Kailey Adams, PhD

Colin Quinn, MSc 2018

Grace Parker, MSc 2018

Aaron Feldhaus, MSc 2017

Sarah Benjaram, MSc 2017

Rachel Jensen, MSc 2016

 

Publications:

     (* denotes student author)

Dixon, JL, Chadwick, OA, Pavich, MJ (2018) Climatically controlled delivery and retention of meteoric 10Be in soils. Geology: doi.org/10.1130/G45176.1

Holmes, D*, McEvoy, J, Dixon, JL, Payne, S (2017) A geospatial approach for identifying and exploring potential natural water storage sites. Water  special issue: Adaptation Strategies to Climate Change Impacts on Water Resources) 9(8) 585; doi: 10:3390/w9080585. Open Access.

Uhlig, D*, Schuessler, JA, Bouchez, J, Dixon, JL, von Blanckenburg, F (2017) Quantifying nutrient uptake as driver of rock weathering in forest ecosystems by magnesium stable isotopes. Biogeosciences: 14, 3111-3128. Open Access.

Dixon, JL, von Blanckenburg, F, Stüwe, K, and Christl, M (2016) Glaciation’s topographic control on Holocene erosion at the eastern edge of the Alps. Earth Surface Dynamics: doi:10.5194/esurf-2016-29. Open Access.

Vitousek, P, Dixon, JL, Chadwick, OA (2016) Parent material and pedogenic thresholds: Observations and a simple model. Biogeochemistry: doi:10.1007/s10533-016-0249-x. Open Access.

Dixon, JL, Chadwick, OA, Vitousek, P (2016) Climate-driven thresholds for chemical weathering in postglacial soils of New Zealand. Journal of Geophysical Research - Earth Surface: 10.1002/2016JF003864. Open Access.

Legrain, N*, J, Dixon, Stüwe, K, von Blanckenburg, F, Kubik, P  (2015) Post-Miocene landscape rejuvenation at the eastern end of the Alps. Lithosphere: L391.1.

Dixon, JL and Riebe, C (2014) Tracing and pacing soil across slopes. Elements: v. 10. P. 363-368.

Sugden, JC*, Hartshorn, AS, J, Dixon, Montagne, C (2014) A slice through time: A Hyalite Canyon soil lithosequence. GSA Field Guides: v. 37, p. 101-114.

Hewawasam, T, von Blanckenburg, F, Bouchez, J, Dixon, JL, Schuessler, JA (2013) Slow advance of the weathering front during deep, supply-limited saprolite formation in the tropical highlands of Sri Lanka. Geochimica et Cosmochimica Acta: v. 118, p. 202-230.

Dixon, JL and von Blanckenburg, F (2012) Soils as pacemakers and limiters of global silicate weathering. Comptes Rendus Geoscience: v. 344. P. 597-609.

Dixon, JL, Hartshorn, AS, Heimsath, AM, Dibiase, R, and Whipple, KX (2012) Chemical weathering response to tectonic forcing: A soils perspective from the San Gabriel Mountains, California. Earth and Planetary Science Letters: 10.1016/j.epsl.2012.01.010

Dixon, JL (2011) Deceptively old Alpine gorges. Nature-Geoscience: News and Views. v. 4, p. 8-9.

Rasmussen, C, Brantley, Richter, D, Blum, A, Dixon, J and White, AF (2010) Strong climate and tectonic control on plagioclase weathering in granitic terrain, Earth and Planetary Science Letters: v. 301, p. 521-530.

Dixon, JL, Heimsath, AM, Burke, BC and Amundson, R (2009) The critical role of climate and saprolite weathering in landscape evolution. Earth Surface Processes and Landforms: v. 34, p. 1507-1521.

Dixon, JL, Heimsath, AM, Kaste, J and Amundson, R (2009) Climate driven processes of hillslope weathering. Geology: v. 37, p. 975-978.

Burke, BC, Heimsath, AM, Dixon, JL, Chappell, J, Yoo, K (2009) Weathering the escarpment: chemical and physical rates and processes, south-eastern Australia. Earth Surface Processes and Landforms: 10.1002/esp.1764.

Conference Proceedings (Last 5 years):

Dixon, JL, Benjaram, SS*, Quinn, Q* and Adams, K*. (accepted 2018) Weathering thresholds and the resilience of soils in mountainous systems. 2018 American Geophysical Union, Fall Meeting, Washington DC USA. (Invited Talk)

Dixon, J and Jensen, R* (2018) A Quantitative framework for understanding past environmental change using meteoric 10Be in lake sediments. 2018 European Geophysical Union General Assembly, Vienna Austria. Geophysical Research Abstracts. (Invited Talk)

Dixon, JL and Chadwick, OA (2017) Insights into Meteoric 10Be Dynamics and Climate Stability along the Hawaiian Kohala Climosequence. 2017 American Geophysical Union, Fall Meeting, New Orleans, LA. Abstracts with Programs EP32C-07.

Quinn, C*, Dixon, JL and Wilcox, AC (2017) To Tree, or not to Tree: Sediment Storage in Forested and Non-forested Mountainous Hillslopes of the Bitterroot Mountains, MT. 2017 American Geophysical Union, Fall Meeting, New Orleans, LA. Abstracts with Programs EP33B-1943.

Benjaram, SS* and Dixon, JL (2017) Quantifying Heterogeneities in Soil Cover and Weathering in the Bitterroot and Sapphire Mountains, Montana: Implications for Glacial Legacies and their Morphologic Control on Soil Formation. 2017 American Geophysical Union, Fall Meeting, New Orleans, LA. Abstracts with Programs EP33B-1944.

Nicholas, G*, Dixon, JL, and Pierce, KL (2017) Deciphering the Preparatory and Triggering Factors Responsible for Post-Glacial Slope Failures: Insights from Landslide Age and Morphology in Yellowstone National Park. 2017 American Geophysical Union, Fall Meeting, New Orleans, LA. Abstracts with Programs EP51B-1648.

Dixon, J and Benjaram, S* (2017) Thresholds for soil cover and weathering in mountainous landscapes. 2017 European Geophysical Union General Assembly, Vienna Austria. Geophysical Research Abstracts: 19, EGU2017-10212. (Invited Talk)

Feldhaus, A* and Dixon, JL (2016) Short-term effects of variable snowpack on soil chemical and biophysical weathering. Paper 328-5. GSA Annual meeting in Denver, 2016.

Dixon, JL (2015) Unravelling heterogeneity in erosion-weathering feedbacks and critical zone architecture. 2015 American Geophysical Union, Fall Meeting, San Francisco CA. Abstracts with Programs.

Jensen, R* and Dixon, JL (2015) Meteoric 10Be in Lake Cores as a Measure of Climatic and Erosional Change. 2015 American Geophysical Union, Fall Meeting, San Francisco CA. Abstracts with Programs.

Benjaram, S* and Dixon, JL (2015) Soil chemical weathering under morphologic and climatic controls in the Northern Rockies, Montana. 2015 American Geophysical Union, Fall Meeting, San Francisco CA. Abstracts with Programs.

Ulizio, T*, Bilbrey, C*, Stoyanoff, N* and Dixon, JL (2015) Using confidence intervals and recurrence intervals to determine precipitation delivery mechanisms responsible for mass wasting events. 2015 American Geophysical Union, Fall Meeting, San Francisco CA. Abstracts with Programs.

Dixon, JL, Chadwick, OA, Vitousek, PM (2014) Climate control on soil age and weathering thresholds in young, post-glacial soils of New Zealand.  2014 American Geophysical Union, Fall Meeting, San Francisco, CA. (Invited Talk)

Vitousek, PM, Dixon, JL, Chadwick, OA (2014) Climate variability, soil fertility, and pedogenic thresholds. 2014 Ecological Society of America Meeting, Sacramento, CA.

Dixon, JL, Legrain, N, von Blanckenburg, F, Stuwe, K (2014) Post-Glacial Topographic vs. Tectonic Forcings on Erosion in the Eastern Austrian Alps. Goldschmidt 2014, Sacramento, CA. (Invited Talk)

Uhlig, D, Schuessler, JA, Bouchez, J, von Blanckenburg, F, Dixon, JL (2014) Mg isotopes as weathering tracer in the Critical Zone at Sierra Nevada, CA. Goldschmidt 2014, Sacramento, CA.

Dixon, JL (2013) Climate driven thresholds for post-glacial soil development. EP52A-03. Presented at 2013 American Geophysical Union, Fall Meeting, San Francisco CA. (Invited Talk)