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Site content related to keyword: "New Jersey"

Presentations at GSA (Geological Society of America) 2012 Annual Meeting

David Wunsch, director of the Delaware Geological Survey and state geologist, and Peter McLaughlin, senior scientist with the Delaware Geological Survey, attended the annual meeting of Geological Society of America in Charlotte, N.C., Nov. 4-7.

B9 Stratigraphy of the Sedimentary Rocks of Delaware

B9 Stratigraphy of the Sedimentary Rocks of Delaware

The stratigraphy of the Coastal Plain of Delaware is discussed with emphasis placed upon an appraisal of the stratigraphic nomenclature. A revised stratigraphic column for Delaware is proposed. Rock stratigraphic units, based mainly on data from certain key wells, are described and the published names which have been or which might conceivably be applied to those units are reviewed. In each case a name is chosen and the reasons for the choice are stated. The relationships between the column established for Delaware and the recognized columns for adjacent states are considered. The rock units of the Coastal Plain of New Jersey, Delaware, and Maryland form an interrelated mass. However, profound facies changes do occur, particularly in the dip direction, but also along the strike. Thus, attempts to extend units established in the outcrop belt almost indefinitely into the subsurface have been unsatisfactory.

RI71 Internal Stratigraphic Correlation of the Subsurface Potomac Formation, New Castle County, Delaware, and Adjacent Areas in Maryland and New Jersey

RI71 Internal Stratigraphic Correlation of the Subsurface Potomac Formation, New Castle County, Delaware, and Adjacent Areas in Maryland and New Jersey

This report presents a new time-stratigraphic framework for the subsurface Potomac Formation of New Castle County, Delaware, part of adjacent Cecil County, Maryland, and nearby tie-in boreholes in New Jersey. The framework is based on a geophysical well-log correlation datum that approximates the contact between Upper and Lower Cretaceous sediments. This datum is constrained by age determinations based on published and unpublished results of studies of fossil pollen and spores in samples of sediment cores from boreholes in the study area. Geophysical log correlation lines established above and below the datum approximate additional chronostratigraphic surfaces. The time-stratigraphic units thus defined are not correlated parallel to the basement unconformity, as in previous practice, but instead onlap it in an updip direction. In future studies, the sedimentary facies of the Potomac Formation within each time-stratigraphic layer may be mapped and analyzed as genetically related contemporaneous units. This new stratigraphic framework will allow better delineation of the degree of lateral connection between potential aquifer sands, thus enhancing understanding of aquifer architecture.

Number of Pages: 
20

OFR42 Catalog of Earthquakes in Delaware

OFR42 Catalog of Earthquakes in Delaware

The occurrences of earthquakes in northern Delaware and adjacent areas of Pennsylvania, Maryland, and New Jersey are well documented by both historical and instrumental records. Over 550 earthquakes have been documented within 150 miles of Delaware since 1677. One of the earliest known events occurred in 1737 and was felt in Philadelphia and surrounding areas. The largest known event in Delaware occurred in the Wilmington area in 1871 with an intensity of VII (Modified Mercalli Scale). The second largest event occurred in the Delaware area in 1973 (magnitude 3.8 and maximum Modified Mercalli Intensity of V-VI). The epicenter for this event was placed in or near the Delaware River. Sixty-nine earthquakes have been documented or suspected in Delaware since 1871.

OFR4 Papers Presented by Staff Members of the Delaware Geological Survey at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974

OFR4 Papers Presented by Staff Members of the Delaware Geological Survey at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974

This report is a compilation of four papers presented by DGS staff members at the Baltimore Meeting of the Northeastern Section of the Geological Society of America, March, 1974.

B3 Marine Upper Cretaceous Formations of the Chesapeake and Delaware Canal

B3 Marine Upper Cretaceous Formations of the Chesapeake and Delaware Canal

In the Coastal Plain of Delaware, the non-marine Cretaceous sands and clays are separated from the Tertiary formations by a series of marine formations of Upper Cretaceous age. The sedimentary and hydrologic characteristics of these formations deserve detailed study because some of them are water-bearing beds. whereas others act as confining beds. A clear understanding of their relative age. and the presence or absence of unconformities is needed for proper correlation with formations found in wells throughout the State. as well as in Maryland and New Jersey.

Earthquake rattles New Jersey and Delaware

Earthquake reported July 1 (credit NBC News 10)

A minor earthquake occurred near Pennsville, N.J., at 9:44 a.m., Wednesday, July 1, according to the Delaware Geological Survey (DGS) at the University of Delaware. The earthquake, which had a magnitude of 2.8, was recorded at the three northern stations of the DGS seismic network.

Earth's shift rattles state, some nerves - Centered in N.J., quake sounded like a loud noise

Delaware Geological Survey geologist, Stefanie Baxter shows the seismic recordings from detectors Wednesday.

When the earthquake hit a little before 10 a.m., everyone who heard the crack and felt the ground rumble thought something had exploded or crashed. Chimneys fell over, windows shattered, people panicked -- on Oct. 9, 1871. The magnitude 4.1 earthquake that shook Wilmington that morning -- the most intense temblor ever recorded in Delaware -- easily outshook the magnitude 2.8 quake that hit the state Wednesday morning.

Overview of Earthquakes in Delaware

DGS Seismic Recorder

Earthquakes occur in northern Delaware and adjacent areas of Pennsylvania, Maryland, and New Jersey. Over 550 earthquakes have been documented within 150 miles of Delaware since 1677, and 69 earthquakes have been documented or suspected in Delaware since 1871.