Crustal Geophysics and Geochemistry Science Center

Integrated Methods Development Project

Geochemical Methods - Dissolved Organic Carbon Studies

Subtask Objectives

There is an increasing awareness that both the quantity and structure of natural organic matter (NOM) influence element mobility and toxicity within an ecosystem. Current methods for NOM characterization and quantification are time consuming and expensive. Recently UV spectrographic and adsorption-emission spectral mapping have shown promise for NOM characterization. Extending spectral methods to evaluate NOM concentration in difficult systems, such as alkaline systems, element/NOM interactions and to a field based system will allow for broad and cost effective characterization.

Objectives include:

  1. Determine if UV and/or emission spectroscopy can be used to characterize and quantify NOM present in alkaline sytems such as the the Mancos shale.
  2. Identify possible target structures within the NOM.
  3. Evaluate the suitability of currently available excitation sources and emissions detectors for the future development of a field based system.

Planned Work

  1. Characterize the composition and reactivity of dissolved organic carbon (DOC) in weathered Green River Formation extracts and prepare a report of the DOC and element chemical data on Green River Formation samples collected in 2010 (in collaboration with Wyoming Landscape Conservation Initiative and Oil Shale assessment projects). This report will include the "clean" technique developed to analyze for DOC in the extracts.
  2. The DOC flourcence data along with the total carbon and SUVA measurements taken on the samples from the Taylor Mountians region of Alaska will be summarized and interperated based on landscape features. These data will be integarted with the metals data from the region and published as part of a manuscript detailing metal distribtion and moblity in the Taylor Mountians region.
  3. Further development of a manual scanning excitation source with multi-wavelength emission detection as the basis for a portable field DOC instrument. Fluorescence signatures of DOC functional groups in standard compounds will be mapped and compared to fluorescence signatures and DOC concentrations from field samples.

Products

Presentations

  • Tuttle, M.L.W., Fahy, J., Grauch, R.I., Stillings, L., 2009, Salt and selenium in the upper Colorado River: processes of supply and transport from the Cretaceous Mancos Shale: Geological Society of America Abstracts with Programs, v. 41, p. 682.

Reports and Articles

  • Tuttle, M.L.W., and Breit, G.N., 2009, Weathering of the New Albany Shale, Kentucky, USA: I. Weathering zones defined by mineralogy and major-element composition: Applied Geochemistry, 24 (8), pp. 1549-1564, doi:10.1016/j.apgeochem.2009.04.021.
  • Tuttle, M.L.W., Breit, G.N., and Cozzarelli, I.M., 2009, Processes affecting δ34S and δ18O values of dissolved sulfate in alluvium along the Canadian River, central Oklahoma, USA: Chemical Geology, 265 (3-4), pp. 455-467.
  • Tuttle, M.L.W., Breit, G.N., and Goldhaber, M.B., 2009, Weathering of the New Albany Shale, Kentucky: II. Redistribution of minor and trace elements: Applied Geochemistry, 24 (8), pp. 1565-1578, doi:10.1016/j.apgeochem.2009.04.034.
  • Tuttle, M.L., and Grauch R.I., 2009, Salinization of the upper Colorado River—Fingerprinting geologic salt sources: U.S. Geological Scientific Investigations Report, 2009-5072, 62 p.

Contact Information

Thomas Chapin
Box 25046 MS 964 Denver Federal Center
Denver, CO 80225-0046
Phone: 303-236-5795
Email: Thomas Chapin

Michelle Tuttle
Box 25046 MS 964 Denver Federal Center
Denver, CO 80225-0046
Phone: 303-236-1944
Email: Michele Tuttle

Bronwen Wang
4210 University Drive
Anchorage, AK 99508-4626
Phone: 907-786-7110
Email: Bronwen Wang

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