New Castle County
OFR54 Bedrock Geologic Map of the Delaware Piedmont
The Piedmont rock units in Delaware, and bedrock geologic map of Schenck et al. (2000) are revised in this report based on new rock geochemistry, geochronometric data, petrography, and recent detailed mapping. Major revisions include:
GM26 Geologic Map of the Cecilton and Middletown Quadrangles, Delaware
Mapping was conducted using field maps at a scale of 1:12,000 with 2-ft contours. Stratigraphic boundaries drawn at topographic breaks reflect detailed mapping using contours not shown on this map. Most stratigraphic units mapped in stream valleys are projected from subsurface data. Except for a few erosional bluffs, these units are covered by colluvium. This map supersedes Geology of the Middletown-Odessa Area, Delaware: Delaware Geological Survey Geologic Map Series No. 2 (Pickett and Spoljaric, 1971).
OFR55 Delaware Geological Survey Petrographic Data Viewer
Petrography is a branch of geoscience focused on the description and classification of rocks, primarily by microscopic study of optical properties of minerals. A thin sliver of rock is cut from a sample, mounted on a glass slide, ground to approximately 30 microns (0.03mm), and viewed under a microscope that uses polarized light. By observing the colors produced as plain polarized light and crossed (90 degrees) polarized light shines through the minerals, petrologists can determine the minerals that comprise the sampled rock.
RI82 Southern New Castle – Northern Kent Counties Groundwater Monitoring Project: Results of Subsurface Exploration and Hydrogeological Studies
The Delaware Geological Survey, in cooperation with the Department of Natural Resources and Environmental Control, completed a groundwater-monitoring, infrastructure-construction, and data-collection project in southern New Castle and northern Kent Counties, Delaware.
OFR51 Groundwater Monitoring Procedures Part 1: Equipment and Procedures for Manual and Automated Field Measurement of Groundwater Levels in Dedicated Monitoring Wells
The Delaware Geological Survey (DGS) has measured, managed, and distributed groundwaterlevel data for several decades using widely accepted procedures and practices, many of which were derived from interactions with staff of the USGS, consulting firms, and other state agencies. Many of the individual methods and procedures have been described in DGS reports, however, written documentation for these tasks have not been assembled in a single published document.
National Ground Water Monitoring Network – Delaware
The DGS has been a data provider for the National Ground-Water Monitoring Network (NGWMN) since 2016. NGWMN is a consortium of state and local agencies and the U.S.