Interdisciplinary studies in the Critical Zone, Boulder Creek catchment, Front Range, Colorado
What: The Keck Colorado 09 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; (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 14-August 11
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 Description and Goals
General goals of the Keck Colorado Project include characterizing the critical zone and its development, geochemistry and hydrology, and hands-on experience with field geophysical techniques used to investigate the shallow subsurface down to fresh bedrock. Broader research questions include:
- “How does critical zone development vary across erosional and ecological regimes?”
- “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 with critical zone development?”
- “How does land-use history, including mining and deforestation, impact critical-zone processes in the two lower-elevation sites?”
Student Projects
Students and project faculty will collect data and/or solid or liquid samples at field sites and will work on laboratory preparation and initial sample treatment at the Mountain Research Station or at the University of Colorado. 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. Potential student projects for 2009 include, but are not limited to:
- Characterizing the chemistry of shallow groundwater and meltwater near late-lying snowfields in the alpine zone and/or from baseflow in deeply weathered areas.
- Field mapping and measurement of the volume and chemistry of sediment disturbed by historic prospecting in Gordon Gulch and comparison to LiDAR data.
- Mapping the depth to bedrock and the structure of the shallow subsurface in Gordon Gulch and the Betasso area using seismic refraction and ground-penetrating radar techniques.
- Measuring variations in soil morphology and chemistry along a slope transect from ridge crest to channel.
- Measurement of fracture spacing, width and orientation in surface and adjacent subsurface (mine portal or drill hole) exposures. Fracture density has a strong influence on long-term rates of weathering and erosion.
- Assessing the contribution of eolian material to soils in the Green Lakes (alpine) catchment.
Field Conditions
We’ll work 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 (http://www.colorado.edu/mrs/fac.html) 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 second 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)
- Structural geology, geophysics or field mapping (valuable)
- GIS or a strong background in supporting science (useful)
