Lynch Heights Formation

RI79 Simulation of Groundwater Flow and Contaminant Transport in Eastern Sussex County, Delaware With Emphasis on Impacts of Spray Irrigation of Treated Wastewater

This report presents a conceptual model of groundwater flow and the effects of nitrate (NO3-) loading and transport on shallow groundwater quality in a portion of the Indian River watershed, eastern Sussex County, Delaware. Three-dimensional, numerical simulations of groundwater flow, particle tracking, and contaminant transport were constructed and tested against data collected in previous hydrogeological and water-quality studies.

GM20 Geologic Map of the Millsboro and Whaleysville Quadrangles, Delaware

The geological history of the surficial units of the Millsboro Quadrangle and
Delaware portion of the Whaleysville Quadrangle was the result of deposition of the
Beaverdam Formation during the late Pliocene and its subsequent modification by
erosion and deposition related to sea-level fluctuations during the Pleistocene and late
Pleistocene upland swamp and bog deposition. The geology at the land surface was then
further modified by periglacial activity that produced dune deposits and Carolina Bays in

GM19 Geologic Map of the Frankford and Selbyville Quadrangles, Delaware

The geological history of the surficial units of the Frankford and Delaware
portion of the Selbyville Quadrangles was the result of deposition of the Beaverdam
Formation during the late Pliocene and its subsequent modification by erosion and
deposition related to sea-level fluctuations during the Pleistocene. The geology at the
land surface was then further modified by periglacial activity that produced dune deposits
in the map area. Surficial geologic mapping was conducted using field maps at a scale of

RI78 Subsurface Geology of the Area Between Wrangle Hill and Delaware City, Delaware

The geology and hydrology of the area between Wrangle Hill and Delaware City, Delaware, have been the focus of numerous studies since the 1950s because of the importance of the local groundwater supply and the potential environmental impact of industrial activity. In this report, 490 boreholes from six decades of drilling provide dense coverage, allowing detailed characterization of the subsurface geologic framework that controls groundwater occurrence and flow.

GM18 Geologic Map of the Bethany Beach and Assawoman Bay Quadrangles, Delaware

The geologic history of the surficial units of the Bethany Beach and Assawoman Bay Quadrangles is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology reflects this complex history onshore, in Indian River Bay and Assawoman Bay, and offshore in the Atlantic Ocean.

GM17 Geologic Map of the Harbeson Quadrangle, Delaware

The complex geologic history of the surficial units of the Harbeson Quadrangle is one of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology is further complicated by periglacial activity that produced dune deposits and Carolina Bays scattered throughout the map area.