112-3 Ground-Based and Airborne Geophysics Reveal New Insights Into Local Bedrock Topography

Session: Geophysics in Investigating and Exploring for Mineral, Energy and Groundwater Resources (Posters)

Poster Booth No.: 237

Presenting Author:

Aiden Fanning

Authors:

Fanning, Aiden¹, Drager, Lillian Rose², Ortman, Caleb³, Kiene, Lani⁴, Thomason, Jason F.⁵, Young, Steven⁶, Balikian, Riley⁷, Malone, David H.⁸, Mwakanyamale-Gilkie, Kisa⁹

(1) Illinois State University, Normal, IL, USA, (2) Illinois State University, Normal, IL, USA, (3) Illinois State University, Normal, Illinois, USA, (4) Illinois State University, Normal, Illinois, USA, (5) Illinois State Geological Survey, Champaign, IL, USA, (6) Illinois State Geological Survey, Champaign, Illinois, USA, (7) Illinois State Geological Survey | Hydrogeology and Geophysics, Champaign, IL, USA, (8) Illinois State University, Normal, IL, USA, (9) Illinois State Geological Survey, Champaign, Illinois, USA,

Abstract:

We used 2-dimensional electrical resistivity tomography (ERT)  and passive-seismic data processed using the horizontal-to-vertical spectral ratio (HVSR) technique to support a helicopter time-domain electromagnetic (HTEM) project in northern Illinois.  The HTEM campaign is the first geophysical dataset to cover this study area with high resolution subsurface data.  This region includes a deeply incised bedrock valley that plays an important role in groundwater resources in the region.  HTEM data have revealed new topographic features that suggest changes to previous interpretations of bedrock topography.  To corroborate features found in HTEM data, we collected 16 HVSR soundings and around 2800 meters of ERT data along a single profile across a new bedrock tributary reflected in the HTEM data.  These surface-based geophysical datasets help us to better assess the utility and impact of airborne geophysical methods in near-surface geologic and hydrogeologic characterization of glacial environments.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9305

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