Interdisciplinary studies in the Critical Zone, Boulder Creek catchment, Front Range, Colorado
Keck Colorado group in the Green Lakes basin, highest of the three study catchments.
What: The Keck Colorado 2011 project will work with a large interdisciplinary study (Boulder Creek Critical Zone Observatory: Weathered profile development in a rocky environment and its influence on watershed hydrology and biogeochemistry-NSF 0724960) directed by Suzanne Anderson, Institute for Arctic and Alpine Studies (INSTAAR), University of Colorado. The Keck Project focus is measurement and sampling of geologic deposits and processes in the critical zone, “the heterogeneous carapace of rock in various stages of decay, overlying soil, and the ecosystems they support… fundamental characteristics of the critical zone, such as its thickness, the character of the weathered rock and soil layers and the biological activity within them, together control the passage of water, the chemical processes operating, the material strength, and the function of subsurface ecosystems.” The “observatory” consists of 3 small, instrumented sites in the Boulder Creek basin: (1) Green Lakes Valley-a steep, glaciated alpine area in the Boulder watershed where “fresh” materials are exposed at the surface; (2) Gordon Gulch-a forested, mid-elevation catchment developed in weathered materials, and (3) Betasso-a steep, lower-elevation basin where surficial deposits are of variable thickness.
When: July 13-August 10
Where: Middle Boulder Creek catchment, Colorado Front Range
Who: David Dethier (Williams College) and 3 students with assistance from Matthias Leopold (Technical University of Munich)
Project overview and goals
General goals of the Keck Colorado Project include making field measurements and collecting samples to help characterize the critical zone and its development, geochemistry and hydrology, and gaining hands-on experience with field geophysical techniques used to investigate the shallow subsurface down to fresh bedrock. Broader research questions include:
- “How does soil development and chemistry vary across erosional and ecological regimes in the study area?”
- “How does the distribution of critical zone development control the hydrologic response of the catchments to both snow and rainfall?”
- “How do weathering and nutrient fluxes vary across the study catchments?”
- “How does land-use history, including mining and deforestation, impact critical-zone processes in the two lower-elevation sites?”
- “How fast is sediment transported on hillslopes and in the channels of the study catchments
Student Projects
Students and project faculty will collect data and/or solid or liquid samples at field sites. We will work on laboratory preparation and initial sample treatment at MRS or at the extensive analytical facilities at INSTAAR in Boulder. I expect that participants will return to their home schools with field data, initial results of some laboratory measurements and samples ready for additional analysis. Data from geophysical (after post-processing) and geochemical analyses (as necessary) will probably return sometime in the fall semester. Analysis and interpretation of field and laboratory results at the home institution will be supervised by the student’s advisor and aided by the Project Director. Potential student projects include:
- Characterizing the chemistry of shallow groundwater and meltwater near late-lying snowfields in Green Lakes basin and/or from baseflow in deeply weathered areas.
- Using synoptic sampling of stream chemistry to help study weathering rates in Gordon Gulch.
- Measuring local variations in rock strength and erodibility using Schmidt hammer techniques.
- Mapping the depth to bedrock and the structure of the shallow subsurface in Gordon Gulch using resistivity and ground-penetrating radar techniques.
- Measuring variations in soil morphology, chemistry, sediment generation and transport processes along slope transects from ridge crest to channel using field, geochemical and cosmogenic radionuclide (CRN) techniques.
- Comparing the coupling between hillslope erosional processes, channel morphology and sediment transport in Betasso and Gordon Gulch using cosmogenic radionuclide (CRN) techniques.
Field Conditions
Collecting a core for studies of Holocene climate change and mercury deposition, N. Boulder Creek, Colorado
We’ll be at elevations ranging from 5,000 to 12,500 feet and working in environments from the hot semidesert to late-lying snowfields and summer hailstorms! Participants will stay at an elevation of 9500 ft at the University of Colorado’s Mountain Research Station on the shoulder of Niwot Ridge and within hiking distance of the Green Lakes site. Cabin accommodations are rustic but they’ll serve us well! Nederland, the nearest town, is about 20 minutes to the south. The Boulder urban area is about an hour away. The Lab has a research building with a library, a few computers and wireless connections. We’ll have breakfast and dinner 5 days a week at the dining hall and we’ll make bag lunches to take to the field. We’ll make other arrangements for Saturdays and Sundays!
Course Preparation
Important for the fourth year of this interdisciplinary project is a strong interest in surface and near-surface processes and in interdisciplinary science, a record of hard work and the ability to follow through. We would prefer gregarious, “can-do” students with a background in geology or physical geography and coursework in:
- Mineralogy and/or geochemistry
- Geomorphology or Quaternary geology or hydrology
- Sedimentology and/or soils (valuable)
- Field mapping, structural geology, geophysics or (valuable)
- GIS or a strong background in supporting science (useful)
