The Delaware Geologic Information Resource (DGIR) is an online data display tool and map viewer for a variety of geologic and hydrologic information released by the Delaware Geological Survey. It was designed to deliver the most commonly available and requested geologic and hydrologic information that is appropriate for use in hydrologic studies, required by regulation and ordinance, and to support state resource management decisions.
The Delaware Geological Survey (DGS) currently monitors groundwater levels in a network of 68 wells in Delaware. Long time-series of water levels in major aquifers serve as critical baseline data for resource management and analyses of aquifer response to pumping, climatic variability, drought hazards, seawater intrusion, and interaction with streams and their ecosystems.
The Delaware Geological Survey (DGS) released a new technical report entitled Simulation of Groundwater Flow in Southern New Castle County, Delaware, which was prepared by Changming He and A. Scott Andres of the DGS.
DGS Report of Investigations No. 77 is a preliminary step in developing a detailed understanding of the subsurface hydrology and evaluating groundwater availability in major aquifer systems beneath southern New Castle County and parts of northern Kent County, which are expected to have greater demands for groundwater in the next 20 years due to population growth.
To understand the effects of projected increased demands on groundwater for water supply, a finite-difference, steady-state, groundwater flow model was used to simulate groundwater flow in the Coastal Plain sediments of southern New Castle County, Delaware. The model simulated flow in the Columbia (water table), Rancocas, Mt. Laurel, combined Magothy/Potomac A, Potomac B, and Potomac C aquifers, and intervening confining beds.
The following table displays the correlation of hydrologic units to geologic units recognized by the Delaware Geological Survey in the Atlantic Coastal Plain.
Ground water comprises nearly all of the water supply in Kent County, Delaware. The confined aquifers of the area are an important part of this resource base. The aim of this study is to provide an up-to-date geologic framework for the confined aquifers of Kent County, with a focus on their stratigraphy and correlation. Seven confined aquifers are used for water supply in Kent County. All occur at progressively greater depths south-southeastward, paralleling the overall dip of the sedimentary section that underlies the state.
This map shows the saturated thickness of the water-table aquifer. This aquifer consists of the deposits of the Columbia Formation and those portions of the Magothy and Englishtown-Mt. Laurel formations, and Rancocas Group that are hydraulically connected with the Columbia deposits (see Groot, Demicco, and Cherry, 1983). For example, large, saturated thicknesses in the zone trending northeast-southwest near Townsend reflect the addition of the sands of the Rancocas Group to the total thickness of the sands of the overlying Columbia Formation.
In recent years there has been a renewed interest by both amateur and professional paleontologists in the rich upper Cretaceous exposures along the Chesapeake and Delaware Canal, Delaware (Fig. 1). Large quantities of fossil material, mostly clams, oysters, and snails have been collected as a result of this activity. Recent dredging (1978, 1981) by the United States Army Corps of Engineers has helped expose a rich vertebrate fossil assemblage. It includes representatives from the classes Reptilia, Osteichthyes, and Chondrichthyes.