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 12 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 (Fig. 1): (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 11-August 8

Where: Middle Boulder Creek catchment, Colorado Front Range

Who: David Dethier (Williams College) and 6 students with assistance from Will Ouimet (University of Connecticut) and Matthias Leopold (Technical University of Munic

Project description 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 the 2010 4-Mile fire, impact stream sediment and geochemistry in the basin?”
  • “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 MSR, USGS or at the extensive analytical facilities at INSTAAR in Boulder. 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. Some potential student projects include:

  1. Characterizing the chemistry of shallow groundwater and meltwater near late-lying snowfields in Green Lakes basin and/or from baseflow in deeply weathered areas.
  2. Mapping the depth to bedrock and the structure of the shallow subsurface in Gordon Gulch using seismic refraction and ground-penetrating radar techniques.
  3. Measuring variations in soil chemistry, morphology, sediment generation and transport processes along slope transects from ridge crest to channel.
  4. Investigating the coupling between hillslope erosional processes, channel morphology and sediment transport in Betasso and Gordon Gulch
  5. Assessing the contribution of eolian material to soils in the Green Lakes (alpine) catchment.
  6. Characterizing the Boulder Creek ‘knickzone’ and its role in determining hillslope and channel processes throughout the CZO study area.

Working Conditions

Colorado2011_1We’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! Once in the field we’ll generally be hiking in rolling to steep terrain. 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 and include bunk beds with mattresses, so you need to bring your own sleeping gear. Nederland, the nearest town, is about 20 minutes to the south and we’ll generally eat dinner there on Friday nights. The Boulder urban area is about an hour away. The Research Station has a laboratory building with a library, a few computers and wireless connections. On a regular basis we’ll work about 6 days a week and take Sundays off for other field trips, relaxation or catching up on sleep and other activities. We’ll have breakfast and dinner 6 days a week at the dining hall and we’ll make bag lunches to take to the field. Breakfast is at 6:45 AM and dinner at 6 PM. We’ll do our best to adjust our field schedule to hit both those times. Once we are working on our projects we’ll usually meet after dinner to look at data, figure out where we’ll go and what we’ll do the next day. Most of the field studies will result in cooperative work where two or all of us help with one person’s project on one day and then move to another project the next day, etc. When the project is running geophysical lines, taking cores or doing other things that require “extra hands”, we’ll all help.

Course Preparation

Important for the fifth 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:

  • Earth materials and/or geochemistry
  • Geomorphology/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)