Share

First State Geology Newsletter Signup

First State Geology has been the newsletter of DGS for over 25 years.

Click here to signup!

Site content related to keyword: "mapping"

Outer Continental Shelf Core and Sample Repository

Project Contact(s):

The Delaware Geological Survey's Outer Continental Shelf (OCS) Core and Sample Repository is a large collection of cores and samples from oil and gas wells drilled offshore the Atlantic Coast of the U.S. during the 1970s and 1980s. This collection was assembled from the contributions of federal agencies, other state agencies, and private institutions that have recognized the value of having a centralized repository for this material.

First 1:24,000 scale Geologic Map Published

First 1:24,000 scale Geologic Map Published
Date: Jul 1970

Geologic Map Series No. 1
Geology of the Chesapeake and Delaware Canal Area, Delaware
By Thomas E. Pickett
1970

First 1:24,000 scale Hydrologic Map Published

First 1:24,000 scale Hydrologic Map Published
Date: Apr 1972

Geohydrology of the Dover Area, Delaware
Hydrologic Map Series No. 1
By Ken D. Woodruff
1972

IS6 Delaware's State Boundaries

Delaware's State Boundaries

One hundred seventy-nine monuments help to mark Delaware's boundaries with Maryland, Pennsylvania, and New Jersey. Although there are only four major boundaries, there are seven boundary lines that make up the confines of the State. They are the east-west boundary, or Transpeninsular Line; the north-south boundary, or the Tangent Line, Arc, and North lines;; the Delaware-Pennsylvania boundary, including the Top of the Wedge Line and the 12-mile Circle; and the Delaware-New Jersey boundary including the 1934 Mean Low Water Line and the Delaware Bay Line. Only the Transpeninsular, Tangent, Arc, North, 12-mile Circle, and 1934 Mean Low Water lines are monumented. The Delaware Bay Line is defined by the navigational
channel. The boundaries described here evolved through long, complex histories (see references). They are based largely on adjudication in England of conflicting claims by the Penns and the Calverts for the Pennsylvania and Maryland colonies.

DGS Digital Datasets

In the same ways as our printed publications, digital data released by the DGS represent the results of original professional research and as such are used by professionals and the public.

Interactive Map of Delaware Earthquakes

Map and data listing of all earthquakes with an epicenter within the State of Delaware.

RI53 Geology of the Seaford Area, Delaware

RI53 Geology of the Seaford Area, Delaware

This report supplements the map "Geology of the Seaford Area, Delaware" (Andres and Ramsey, 1995). The map portrays surficial and shallow subsurface stratigraphy and geology in and around the Seaford East and Delaware portion of the Seaford West quadrangles. The Quaternary Nanticoke deposits and Pliocene Beaverdam Formation are the primary lithostratigraphic units covering upland surfaces in the map area. Recent swamp, alluvial, and marsh deposits cover most of the floodplains of modern streams and creeks. The Miocene Choptank, St. Marys, and Manokin formations occur in the shallow subsurface within 300 ft of land surface. The Choptank, St. Marys, and Manokin formations were deposited in progressively shallower water marine environments. The Beaverdam Formation records incision of underlying units and progradation of a fluvial-deltaic system into the map area. The geologic history of the Quaternary is marked by weathering and erosion of the surface of the Beaverdam and deposition of the Nanticoke deposits by the ancestral Nanticoke River. Depositional environments in the Nanticoke deposits include fresh water streams and ponds, estuarine streams and lagoons, and subaerial dunes.

SP4 Generalized Geologic Map of Delaware

SP4 Generalized Geologic Map of Delaware

The Generalized Geologic Map of Delaware is a brief summary for general use indicating the major types and locations of rocks present throughout the State, and their interrelationships. The map is preliminary as it is a first step in a continuing program of detailed geologic mapping. It is based upon many existing sources of data; additional detail may be found in the references listed.

OFR17 A Guide to Information on Benchmarks in Delaware

OFR17 A Guide to Information on Benchmarks in Delaware

To conduct an elevation survey, a surveyor needs a starting point for which the exact elevation above mean sea level is known. These starting points are called benchmarks. State and federal agencies install benchmarks throughout every State, creating a network of elevation points which covers the entire continental United States. These benchmarks are considered to be permanent, and usually consist of a brass, bronze, or aluminum disc about 4 inches in diameter mounted in a cement post or in a drill hole in a permanent foundation. Each benchmark also has the installing agency's name and an identification number stamped into it. In December of 1980 the Federal Emergency Management Agency (FEMA) allotted the State of Delaware funds to determine the number and condition of federal benchmarks and other elevation reference control points. The National Flood Insurance Program (NFIP), contained within FEMA, requires accurate flood surveys of property in flood-prone areas. An extensive and accurate benchmark network throughout the State is needed to help meet these needs.

OFR39 Basic Data for the Geologic Map of the Seaford Area, Delaware

OFR39 Basic Data for the Geologic Map of the Seaford Area, Delaware

The Seaford area geologic mapping project (Andres and Ramsey, 1995) was conducted by Delaware Geological Survey (DGS) staff and focused on the Seaford East (SEE) and Delaware portion of the Seaford West (SEW) quadrangles (Fig. 1). Data evaluated in support of mapping from these quadrangles and surrounding areas are documented in this report.

SP16 Generalized Geologic Map of Delaware, Postcard

SP16 Generalized Geologic Map of Delaware, Postcard

Delaware’s oldest rocks are metamorphic crystalline rocks of the central Appalachian Piedmont Physiographic Province. Atlantic Coastal Plain sediments overlie the crystalline rocks of the Piedmont and range in thickness from a feather edge at the Fall Line to approximately 9,000 feet in the southeastern corner of Delaware. Sediments range in age from Early Cretaceous to Holocene.

SP17 The Delaware Geological Survey: The Formative Years, 1951-1969

SP17 The Delaware Geological Survey: The Formative Years, 1951-1969

Emphasis is placed herein on the years of Dr. Groot's leadership of the Survey. The remarkable work of James C. Booth in the last century is acknowledged but has elsewhere been entered in history. Some continuing activities of the Survey after 1969 are noted together with comments of an experienced observer; this current period may someday receive the attention of a recorder having the enhanced perspective of time.

Delaware Offshore Geologic Inventory

Delaware Offshore Geologic Inventory Map
Project Contact(s):

Since 1992, the Delaware Geological Survey (DGS) has compiled a geologic database known as the Delaware Offshore Geologic Inventory (DOGI) that consists of sediment samples, radiocarbon and amino acid racemization dates, seismic profiles, and vibracores taken from the nearshore and inner continental shelf in state and federal waters. Most of the 366 vibracores are stored at the DGS on-site core and sample repository.

The Delaware DataMIL

The Delaware DataMIL

The Delaware DataMIL collects, maps, and serves Delaware's Spatial Data Framework, or basic map datasets, on which state agencies, local and county governments, academic GIS users, and the private sector can use for their own needs. DataMIL also provides access for Delaware topographic maps that replace the old USGS 7.5-minute topographic maps for the State.

Maps and Directions

Maps, driving directions, parking, and contact information for the Delaware Geological Survey.

GM14 Geologic Map of Kent County, Delaware

GM14 Geologic Map of Kent County, Delaware

This map shows the surficial geology of Kent County, Delaware at a scale of 1:100,000. Maps at this scale are useful for viewing the general geologic framework on a county-wide basis, determining the geology of watersheds, and recognizing the relationship of geology to regional or county-wide environmental or land-use issues. This map, when combined with the subsurface geologic information, provides a basis for locating water supplies, mapping ground-water recharge areas, and protecting ground and surface water. Geologic maps are also used to identify geologic hazards, such as flood-prone areas, to identify sand and gravel resources, and to support state, county, and local land-use and planning decisions.

Map Scale: 
100,000

GM13 Geologic Map of New Castle County, Delaware

GM13 Geologic Map of New Castle County, Delaware

This map shows the surficial geology of New Castle County, Delaware at a scale of 1:100,000. Maps at this scale are useful for viewing the general geologic framework on a county-wide basis, determining the geology of watersheds, and recognizing the relationship of geology to regional or county-wide environmental or land-use issues. This map, when combined with the subsurface geologic information, provides a basis for locating water supplies, mapping ground-water recharge areas, and protecting ground and surface water. Geologic maps are also used to identify geologic hazards, such as sinkholes and flood-prone areas, to identify sand and gravel resources, and for supporting state, county, and local land-use and planning decisions.

Map Scale: 
100,000
This page tagged with:

GM12 Geology of the Lewes and Cape Henlopen Quadrangles, Delaware

GM12 Geology of the Lewes and Cape Henlopen Quadrangles, Delaware

The surficial geology of the Lewes and Cape Henlopen quadrangles reflects the geologic history of the Delaware Bay estuary and successive high and low stands of sea levels during the Quaternary. The subsurface Beaverdam Formation was deposited as part of a fluvial-estuarine system during the Pliocene, the sediments of which now form the core of the Delmarva Peninsula. Following a period of glacial outwash during the early Pleistocene represented by the Columbia Formation found to the northwest of the map area (Ramsey, 1997), the Delaware River and Estuary developed their current positions. The Lynch Heights and Scotts Corners Formations (Ramsey, 1993, 1997, 2001) represent shoreline and estuarine deposits associated with high stands of sea level during the middle to late Pleistocene on the margins of the Delaware Estuary. In the map area, the Lynch Heights Formation includes relict spit and dune deposits at the ancestral intersection of the Atlantic Coast and Delaware Bay systems, similar in geomorphic position to the modern Cape Henlopen.

Map Scale: 
24,000