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Site content related to keyword: "Appalachian Piedmont"

RI54 Radiocarbon Dates from Delaware: A Compilation

RI54 Radiocarbon Dates from Delaware: A Compilation

Radiocarbon dates from 231 geologic samples from the offshore, coastal, and upland regions of Delaware have been compiled along with their corresponding locations and other supporting data. These data now form the Delaware Geological Survey Radiocarbon Database.

SP14 Basic Hydrologic Data for Coastal Sussex County, Delaware

SP14 Basic Hydrologic Data for Coastal Sussex County, Delaware

There is no abstract on file for this publication.

SP10 Selected Papers on the Geology of Delaware

SP10 Selected Papers on the Geology of Delaware

The Delaware Academy of Science has been instrumental in informing Delaware citizens about science and utilization of local resources. Since 1970 the annual meeting of the Delaware Academy of Science has been used as a time for presentation of ongoing research in various areas of science in the Delaware region. The proceedings of these meetings have resulted in publication of transactions of the Delaware Academy of Science. The 1976 annual meeting focused on aspects of the geology of Delaware. Members of the Delaware Geological Survey and the Geology Department at the University of Delaware contributed papers in their specific disciplines. This volume presents an overview of studies of geological features and processes of evolution of the geology of Delaware. Although this collection of papers does not represent an all-inclusive study of the subject, the selections included in this volume highlight past, present, and future trends in the study of Delaware's geology. It is hoped that the combined bibliographies of all the papers will provide a comprehensive view of the literature for further investigation into the geology of Delaware.

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.

Exploring the Wilmington Blue Rocks: A GeoAdventure in the Delaware Piedmont

Blue Rocks at Greenway

The Wilmington blue rock, Delaware's most famous rock, underlies both the city of Wilmington and the rolling upland north and east of the city. It is best exposed along the banks of the Brandywine Creek from south of Rockland to the Market Street Bridge. Along this section the Brandywine has carved a deep gorge in the blue rock. The water fall along this four mile gorge is approximately 120', and in the 17th and 18th centuries provided water power for one of the greatest industrial developments in the American colonies. The field trip stops described below are chosen as good examples of blue rock along the Brandywine Creek, and to illustrate how the geology has influenced the development of this area. It is not necessary to visit every stop to become familiar with the blue rocks, you may choose to visit only a few.

The Bringhurst Gabbro: A GeoAdventure in the Delaware Piedmont

Bringhurst Woods Park Rocks, The Bringhurst Gabbro

A field trip to Bringhurst Woods Park is appropriate for students in grades 5 and up (10 years and older), and provides an opportunity to observe intrusive plutonic igneous rocks that have intruded into country rock, which in this case is the blue rock or what geologists call the Brandywine Blue Gneiss. In addition, the minerals in the pluton are large, easily identified, and interesting. Mineral collecting is not allowed within the park, however permission may be obtained to collect along Shellpot Creek southeast of the park. Please do not use rock hammers on the rocks in the park.

OFR19 Regolith Thickness of the Delaware Piedmont

OFR19 Regolith Thickness of the Delaware Piedmont

This map shows the total thickness (regolith) of both the loose, transported material and the weathered rock that overlies crystalline rocks of the Delaware Piedmont. Transported material is generally thin and the weathered rock in place (saprolite) usually makes up the bulk of the regolith. Saprolite may vary gradationally from a weathered rock that has retained much of the characteristics of the parent rock to a product mineralogically and texturally different from its source rock.

OFR11 Effects of Earthquakes and Earth Tides on Water Levels in Selected Wells in the Piedmont of Delaware

OFR11 Effects of Earthquakes and Earth Tides on Water Levels in Selected Wells in the Piedmont of Delaware

Examination of continuous water-level hydrographs from two artesian observation wells in the Piedmont near Newark, Delaware reveals water-level fluctuations caused by earthquakes and by earth tides. The effects of 14 distant earthquakes with MS (surface wave) magnitudes between 6.7 and 8.0 and MB (body wave) magnitudes between 5.9 and 7.0 (National Earthquake Information Service, 1975-1977) have been recorded over a two-year and ten-month period.

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.

OFR38 Data Report on Rock Cores from Red Mill Road, Harmony Road, Prices Corner, and Newport, Delaware

OFR38 Data Report on Rock Cores from Red Mill Road, Harmony Road, Prices Corner, and Newport, Delaware

The Delaware Piedmont is underlain by metamorphosed sedimentary and igneous rocks of Middle Proterozoic to Paleozoic age. The rocks have been studied for many years, but because of poor exposure, high-grade metamorphism, and intense deformation, it has been difficult to identify units, understand their stratigraphic relationships to one another, and determine their origin and history; however, northern Delaware occupies a critical position in the central Appalachian Piedmont, and understanding its geology is key to understanding the geology of this region.

B4 Preliminary Report on the Geology and Ground-Water Resources of Delaware

B4 Preliminary Report on the Geology and Ground-Water Resources of Delaware

Delaware has an abundant supply of ground water of a quality suitable for most purposes. About 30 million gallons of water a day was pumped from the ground in 1954. It is estimated that this is roughly 1/16 of the optimum yield. This water is derived from nine groups or series of water-bearing units and is obtained from wells which yield as much as 1,100 gallons per minute. Thousands of wells serve agriculture, industry, municipalities, and domestic users. Geographically, Delaware is situated along the Atlantic coast of the United States in two physiographic provinces: the Piedmont and the Coastal Plain. The Piedmont is a belt of rolling foothills of the Appalachian Mountains. It is separated from the Coastal Plain by the Fall Line, a narrow zone of rapids or falls along which rivers and creek descend rapidly from the mature valleys of the Piedmont to the sluggish tidal estuaries of the coastal area. The Coastal Plain is a flat or gently undulating plain of relatively low altitude, which borders the Atlantic Ocean and its estuarine embayments.

B2 Geology and Ground-Water Resources of the Newark Area, Delaware with a Section on the Surface Water Resources

Geology and Ground-Water Resources of the Newark Area, Delaware with a Section on the Surface Water Resources

This report describes the geological and lithological conditions in the Newark area, and the occurrence, quantity, and quality of the available ground-water supply. Newark is located on the Fall Line, the boundary between the rolling hills of the Piedmont on the north and the gentle slopes of the Coastal Plain on the south. Because the Piedmont is underlain by dense crystalline rocks and their weathered clayey soils, which are of low water-bearing capacity in contrast to the more permeable silts and sands of the Coastal Plain, the exploration for ground water was confined to the Coastal Plain south and southeast of Newark.

RI27 Ground-Water Investigations in the Delaware Piedmont for the City of Newark, 1976

RI27 Ground-Water Investigations in the Delaware Piedmont for the City of Newark, 1976

Field reconnaissance, geologic mapping, and photogeologic interpretations aided collectively in the identification of 30 potential high-yield well sites in the crystalline rocks of Delaware's western Piedmont. Fracture traces discernable on panchromatic and color infrared photography were identified in the study area. Well locations were selected on individual traces and on fracture trace intersections. Six test wells averaging 468.5 feet in depth were drilled at selected sites. Test analyses indicate that production wells at these sites would have a combined potential estimated at 1.0 to 1.1 million gallons per day of water. A thorough knowledge of the hydrogeologic framework is key to successful ground-water exploration and development. Subsurface fracturing is of prime importance in governing the water-yielding properties in the crystalline rocks. The surface traces of vertical or near-vertical zones of subsurface rock fracture were identified and used as an aid in high-capacity well siting.

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.

SP24 Selected Geomorphic Features of Delaware

SP24 Selected Geomorphic Features of Delaware

The shaded relief image on the left was created using 30-meter resolution Digital Elevation Models (DEMs). The DEMs were developed by John Mackenzie, University of Delaware College of Agriculture and Natural Resources Spatial Analysis Laboratory, from rasterized 1992-93 United States Geological Survey (USGS) Digital Line Graph (DLG) hypsography data. He also combined these data with zero-elevation contours extracted from 1989 Landsat TM Band 7 satellite imagery for coastal quadrangles. The image was digitally enhanced using a false sun angle of 45 degrees shining from the northwest to exaggerate the geomorphic features. In reality the Delaware Coastal Plain is not "mountainous," as it looks in this enhanced image. The hydrology layer was created using USGS 30 x 60 minute and 7.5 minute series DLG data. Municipal boundaries were created using the Delaware Municipal Boundary Framework Layer. Both maps are projected in Universal Transverse Mercator, Zone 18 (UTM 18) on the North American Datum 1983 (NAD83).

SP20 Delaware Piedmont Geology

SP20 Delaware Piedmont Geology

The Red Clay Creek Valley traverses geologic features that have long been recognized as important to science, industry, and history. The reader will note that within the text “Piedmont,” and “Atlantic Coastal Plain” are capitalized. This is because these are formal geologic provinces. The “Fall Line” or “fall zone” is also an important geologic area. The Fall Line is the contact where the hard crystalline rocks of the Piedmont dip under and disappear beneath the sediments of the Coastal Plain. The fall zone is a narrow zone that parallels the Fall Line where rapids and waterfalls are common. The landscape and rock types shown in northern Delaware are classical examples of the larger geologic features that dominate the geology of eastern North America.

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.

SP8 Memoir of the Geological Survey of the State of Delaware

SP8 Memoir of the Geological Survey of the State of Delaware

The following report of the geological survey of the state of Delaware, conducted in the years 1837 and 1838, embraces all the observations and examinations which were made during the continuance of the survey, including those contained in the first and second annual reports, already laid before the legislature.

SP2 Long-Range Plan for Water Resources Investigations in Delaware

SP2 Long-Range Plan for Water Resources Investigations in Delaware

In order to obtain sufficient data which will enable the State to develop its water resources to the fullest extent of which they are capable, a series of systematic investigations is necessary. A long-range plan describing these studies is the subject of this report. A brief discussion of water in Delaware is presented first to provide a proper background for the long-range plan. The plan itself merely outlines the overall objectives and types of investigational work that must be pursued if the State is to develop its water resources wisely.