Stratigraphic and geomorphic framework of uppermost Cenozoic deposits in the southern Delmarva Peninsula, Virginia and Maryland

Influence of stream‐groundwater interactions in the streambed sediments on NO3− flux to a low‐relief coastal stream

“…The model domain in the region of the stream represents half the channel width, with the vertical boundary at the center of the stream channel specified as a no-flow boundary. The aquifer is about 10 m thick [Hubbard et al, 2001;Mixon, 1985]; a no-flow boundary is assumed at the base of the domain. Hydraulic head recorded at a hilltop well showed that the upland water table is fairly stable during transient rainfall events.…”

Water quality in the surficial aquifer near agricultural areas in the Delaware Coastal Plain, 2014

“…and Lynch Heights Fm., which occur on the eastern side and updip section of the Omar Fm. north of Indian River Bay (Ator and others, 2005;Mixon, 1985;Owens and Denny, 1979;Ramsey, 1997). These formations are of Quaternary through late Miocene age.…”

Heterogeneity of Sedimentary Aquifers: effect on microbial dynamics at successive spatial scales as revealed by geophysical imaging: Final report to the Department of Energy on Award DE-FG02-9ER62478

“…A statistical approach General,--The closely-spaced data collected in the course of the North Oyster, Virginia, study reveal a more complex stratigraphy than does the regionally oriented study of Mixon (1985). Comparison of cores collected along the centerlines of the flow cells with ground-penetrating radar profiles reveals a succession of high-frequency sequences, apparently the consequence of sea level oscillations during late Pleistocene time.…”

“…A very fine micaceous sand with lenses of silt and clay occupies the lower half of the core. The sediments of the Narrow Channel Area correspond to the upper unit of the Wachapreague Formation as defined by Mixon (1985), while in those of South Oyster area both of Mixon's (1985) units are present. In terms of grain size, permeability distributions, amount of fine-grained material (clay and silt), and organic matter present, the South Oyster Area possesses greater heterogeneity than does the Narrow Channel Area Defining lithofacies.--Earlier investigations of the Oyster aquifer (Parsons et al, in press; Swift et al, in press; Mueller et al, in review) have focused on the more heterogeneous Butlers Bluff Member of the Nassawadox Formation.…”

“…The Poorly Sorted Gravelly Sand is probably deposit of the alongshore trough (surf zone), with the Poorly sorted Medium Sand, and the Moderately sorted Medium Sand deposited in beach or near-beach settings, and the Well sorted Fine Sand deposited a little further offshore. These lithofacies comprise Mixon's Upper Unit of the Wachapreague Formation (Mixon, 1985).…”