Evaluation of geophysical techniques for the detection of paleochannels in the Oakland area of eastern Nebraska as part of the Eastern Nebraska Water Resource Assessment

Abstract

Maps of the Oakland, Nebraska, study area showing the elevation of A, base of till (or top of sand) and B, base of sand (or bedrock surface) as estimated from lithologic data from Eastern Nebraska Water Resource Assessment drilled wells using minimum-curvature gridding; C, sand thickness (isopach) is estimated using the till and sand bases ..

Three‐dimensional architecture and hydrostratigraphy of cross‐cutting buried valleys using airborne electromagnetics, glaciated Central Lowlands, Nebraska, USA

“…The ability to resolve targets is controlled by many factors: bandwidth of the measurement; power of the transmitter; height of the sensor; electrical conductivity of the earth materials; and the presence of man‐made infrastructure (power lines, pipelines and train tracks). Highly conductive materials typically impact FDEM systems, which limit the effective depth of investigation (Abraham et al ., ). The process of numerical inversion also introduces a level of non‐uniqueness in the results.…”

“…Boyce & Eyles, ) or, in some cases, ground‐based, two‐dimensional geophysical profiles supplemented by boreholes (e.g. Denne et al ., ; Jørgensen et al ., ; Abraham et al ., ). Resolving the intricate geometries and internal heterogeneities of buried valley deposits requires spatially dense data suitable for three‐dimensional reconstruction of sedimentary bodies.…”

Lithologic influences on groundwater recharge through incised glacial till from profile to regional scales: Evidence from glaciated Eastern Nebraska

“…This investigation is organized around three study areas, referred to below as the Oakland (OAK), Ashland (ASH), and Firth (FIR) study areas, the positions of which were selected to be broadly representative of the region's hydrogeologic conditions (Figure ). The Oakland study area is located within an area of stream‐dissected glacial hills where rolling topography and a stream valley has been eroded out of thick glacial deposits overlain by loess units [ Abraham et al ., ; Gosselin et al ., ; Nasta and Gates , ]. The Ashland study area is within an area of loess‐capped till that has been dissected by a large alluvial system (the Platte River).…”

“…The paleovalleys are incised into underlying Cretaceous, Permian, and Pennsylvanian bedrock units along an overall east to west slope, and are thought to predate at least one advance of the Laurentide ice sheet prior to 640 ka. The paleovalleys have been the focus of recent characterization studies using airborne geophysics [ Abraham et al ., ; Korus et al ., ]. However, the age of the coarse‐grained paleovalley fills are not well constrained and may be preglacial, synglacial, or interglacial in origin.…”