Constraining the Geometry of Subsurface Paleochannels beneath Delaware Bay and the Mid-Atlantic Inner Continental Shelf

Childers, D.P.; Madsen, J.A.; Krantz, D.E., and Deliberty, T.L., 2019. Constraining the geometry of subsurface paleochannels beneath Delaware Bay and the Mid-Atlantic inner continental shelf. Journal of Coastal Research, 35(3), 590–599. Coconut Creek (Florida), ISSN 0749-0208. This study improves the understanding of paleochannels underlying Delaware Bay and the Mid-Atlantic inner continental shelf. Major surfaces interpreted from analog seismic profiles were used in ArcGIS™ to create a three-dimensional (3D) model in ArcScene™ that constrains the geometry and relative age relationships of the paleochannels. Interpolation with kriging in the Geostatistical Analyst tool in ArcGIS was used to generate spatial models that were imported into ArcScene to create 3D perspective views of the primary subsurface features. The results better constrain the geometry of previously mapped paleochannels. These revisions enhance the understanding of the Quaternary geologic evolution of the region in response to sea-level fluctuations. A new nomenclature for previously named paleochannels is proposed based on their relative age relationships. The Central (renamed as Qc1) paleochannel in Delaware Bay is identified as the youngest and continues onto the inner shelf trending SE approximately 50 km across the shelf and then eastward toward Baltimore Canyon. The next oldest Delaware Bay paleochannel, the Southern (Qc2) paleochannel, correlates with the previously identified Orange (Qc2) paleochannel and also trends toward Baltimore Canyon. The oldest paleochannel in the Bay, the Northern (Qc3) paleochannel, is projected beneath the tip of Cape May, New Jersey, and continues on the inner shelf as the earlier defined Green (Qc3) paleochannel.