Abstract

Geophysical techniques provide a relatively rapid and spatially extensive means to indirectly elucidate subsurface critical zone architecture. Moreover, geophysical measurements can help extrapolate discrete measurements from direct subsurface samples and help guide future research efforts. In the spring of 2018, a joint field campaign by Indiana University of Pennsylvania, Dickinson College, Penn State University, Temple University and Rutgers University was conducted to investigate the subsurface architecture of the Cole Farm site in the Susquehanna Shale Hills Critical Zone Observatory. Students enrolled in geophysics classes at their respective institutions conducted seismic refraction and electrical resistivity surveys across two 200-meter transects. Survey locations were chosen to exploit existing infrastructure and measurements at Cole Farm (i.e., GroundHOG, groundwater wells and auger transects). The goals of these surveys were to (1) determine the subsurface geologic and hydrogeologic structure (e.g., depth to bedrock and depth to water table) and (2) identify features that may serve as a preferential flowpaths. We present preliminary results from these surveys including seismic and resistivity tomograms. Our initial results constrain depth to bedrock across the survey transects and highlight architectural features across the valley. These results provide another endmember for comparison of hydrogeophysical structure between the three bedrock lithologies (i.e., shale, meta-sandstone, and limestone) of the SSHCZO. The integrated geophysical approach presented here further supports findings of other geophysical research within the CZO that demonstrates the ability to quickly and efficiently develop critical zone structure models that can reveal the linkage between potential surface and subsurface controls on landscape evolution.

Citation

Gregory Mount*, Jorden Hayes, Perri Silverhart, Callum Richard Wayman, Joanmarie Del Vecchio, Roman A DiBiase, Susan L Brantley (2018): Near-surface Geophysical Characterization of Cole Farms in the Susquehanna Shale Hills Critical Zone Observatory, Pennsylvania, USA. Abstract NS41B-0820 presented at 2018 AGU Fall Meeting, Washington, D.C., 10-14 Dec.

This Paper/Book acknowledges NSF CZO grant support.