Abstract

Electrical resistivity tomography data were collected in the Garner Run subcatchment of the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) from 19 May to 2 June 2018. Garner Run is a headwater subcatchment with a small stream parallel to a syncline fold axis of an erosionally resistant orthoquartzic sandstone with interbedded shale units. The surficial geology at Garner Run is largely controlled by periglacial processes, such as slumps and solifluction lobes that are associated with thawing permafrost soils. Electrical resistivity tomography data were collected to better understand the subsurface architecture and to identify variations in and delineate the depth of valley fill. The valley fill consists of poorly sorted sand to cobble size sediment that has been transported downslope. Understanding the depth and location of these deposits across the valley can be used to better constrain the geomorphological process that formed this region.

Nearly 1.6 km of electrical resistivity data with 3 m spacing were acquired with the IRIS Syscal Kid system using two array types: Wenner and Dipole-dipole. The inverted resistivity images show that there is a decrease in resistivity as surveys approach the centerline of the valley, which we hypothesize to indicate where the fill is the thickest. These data were collected as part of the 2018 Geopaths Near Surface Geophysics Field Experience, an NSF funded program aimed at introducing students typically underrepresented in STEM fields to the field of near-surface geophysics. For future studies, we will jointly interpret seismic refraction, electrical resistivity tomography, and ground penetrating radar datasets to get a complete understanding of this critical zone architecture at Garner Run.

Citation

Yonesha Y Donaldson*, Joaquin Cambeiro, Gina Pope, Paul O'Neill, Gregory Mount, Kristina Keating, Susan Brantley, Jonathan Nyquist (2018): Characterizing the subsurface of the Critical Zone in the Garner Run Catchment at the Susquehanna Shale Hills Critical Zone Observatory using Electrical Resistivity. Abstract NS41B-0819 presented at 2018 AGU Fall Meeting, Washington, D.C., 10-14 Dec .

This Paper/Book acknowledges NSF CZO grant support.