EGU2020-21589
https://doi.org/10.5194/egusphere-egu2020-21589
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Detection of High-Organic-Carbon Features in Sediments by Direct-Push Color Logging

Stefan Klingler1, Ulrike Werban2, Carsten Leven1, Peter Dietrich1,2, and Olaf A. Cirpka1
Stefan Klingler et al.
  • 1University of Tübingen, Center for Applied Geoscience, Hölderlinstr. 12, 72074 Tübingen, Germany
  • 2Helmholtz Centre for Environmental Research – UFZ, Department of Monitoring and Exploration Technologies, Permoserstr. 15, 04318 Leipzig, Germany

A biogeochemical site characterization aims at delineating zones of reducing and oxidizing conditions in the subsurface to infer their influence on solute and contaminant turnover processes along groundwater flow paths. Hereby, large values of the total organic carbon (TOC) content mark reducing conditions in soils and sediments. Dark sediment colors are good predictors for high-TOC zones and thus indicate hotspots of biogeochemical turnover and microbial activity. Traditionally, obtaining the sediment color requires costly sampling, resulting in poor horizontal resolution and related uncertainty caused by interpolation. We suggest using a direct-push soil color optical screening tool to acquire multiple high-resolution vertical color profiles and demonstrate its applicability in floodplain sediments down to 12 m depth. We use Gaussian mixture models for a cluster analysis of the color logs in the CIE L*a*b* color space to identify color-facies, determine facies-specific relationships between the L*a*b* color-values and the TOC content of the sediments, and to construct the 3-D distributions of three distinct facies and organic matter. Direct-push color-logging may also be used for in-situ mapping of redox-zonation, iron content, or sedimentary structures.

How to cite: Klingler, S., Werban, U., Leven, C., Dietrich, P., and Cirpka, O. A.: Detection of High-Organic-Carbon Features in Sediments by Direct-Push Color Logging, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21589, https://doi.org/10.5194/egusphere-egu2020-21589, 2020

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