Airborne geophysical survey: Worcester-Wicomico, Maryland

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Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: U.S. Geological Survey and the Department of Interior
Publication_Date: 2012
Title: Airborne geophysical survey: Worcester-Wicomico, Maryland
Geospatial_Data_Presentation_Form: analog contour map
Online_Linkage:

https://mrdata.usgs.gov/magnetic/show-survey.php?id=MD0070_pg.shp

Description:

Abstract:

Aeromagnetic data were collected along flight lines by instruments in an aircraft that recorded magnetic-field values and locations. In the earlier days of surveying, the only way to represent this data was to generate an analog map with contour lines. This dataset is a representation of the digitized contour lines either by following the lines or by choosing the intersection of the contour and flight-line to create a value of the magnetic field. The values presented are latitude, longitude, and map magnetic-field values.

Purpose:

Aeromagnetic surveys are used for geophysical prospecting. Some variations in magnetic measurements are caused by rocks that contain significant amounts of magnetic minerals (magnetite being the most common). These anomalies reflect variations in the amount and type of magnetic material and the shape and depth of the body of rock. The features and patterns of aeromagnetic anomalies can also be used to delineate details of subsurface geology including the locations of buried faults and the thickness of surficial sedimentary rocks.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 194503
Ending_Date: 194503

Currentness_Reference: ground condition

Status:

Progress: complete
Maintenance_and_Update_Frequency: none planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -75.70
East_Bounding_Coordinate: -75.05
North_Bounding_Coordinate: 38.46
South_Bounding_Coordinate: 38.00

Data_Set_G-Polygon:

Data_Set_G-Polygon_Outer_G-Ring:

G-Ring:

-75.69 38.46, -75.05 38.45, -75.24 38.03, -75.57 38.00, -75.57 38.21, -75.66 38.21, -75.69 38.29, -75.69 38.46

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ecf727ce-5a41-4280-a221-9f35c7f3eabb

Theme:

Theme_Keyword_Thesaurus: none
Theme_Keyword: geophysical surveys
Theme_Keyword: aeromagnetic data
Theme_Keyword: airborne surveys
Theme_Keyword: magnetic surveys
Theme_Keyword: residual magnetic field
Theme_Keyword: total field
Theme_Keyword: magnetic

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: geophysics
Theme_Keyword: geospatial datasets
Theme_Keyword: magnetic field (earth)
Theme_Keyword: aeromagnetic surveying
Theme_Keyword: field monitoring stations

Place:

Place_Keyword_Thesaurus: none
Place_Keyword: United States
Place_Keyword: Maryland
Place_Keyword: MD
Place_Keyword: Worcester
Place_Keyword: Wicomico

Place:

Place_Keyword_Thesaurus: Common Geographic Areas
Place_Keyword: f10005 = Sussex
Place_Keyword: f24039 = Somerset
Place_Keyword: f24045 = Wicomico
Place_Keyword: f24047 = Worcester
Place_Keyword: f51001 = Accomack

Access_Constraints: none
Use_Constraints:

none. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data.

Browse_Graphic:

Browse_Graphic_File_Name:

http://mrdata.usgs.gov/geophysics/surveys/geophysics3/MD/md0070.jpg

Browse_Graphic_File_Description:

Reduced-size image depicting the data, 1118 x 1030 pixels, 96,821 bytes

Browse_Graphic_File_Type: JPEG

Data_Set_Credit:

These USGS employees contributed to reformatting and archiving these data: Viki Bankey, Pat Hill, Holly Hindle, Bob Kucks, Sarah Shearer, Esther Castellanous

Cross_Reference:

Citation_Information:

Originator: U.S. Geological Survey
Publication_Date: 1946
Title:

Magnetic maps of Worcester County and part of Wicomico County, Maryland

Geospatial_Data_Presentation_Form: map
Series_Information:

Series_Name:

U.S. Geological Survey Oil and Gas Investigations Preliminary Map

Issue_Identification: OM-46

Publication_Information:

Publication_Place: Denver, CO
Publisher: U.S. Geological Survey

Other_Citation_Details:

by J.R. Balsley and others map scale 1:125,000

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

The data shown on the original map have been processed using various formulas and methods that are not usually documented but that represent industry standard practices for airborne data reduction. For example, position is listed as latitude and longitude, but these values were derived from the raw navigation data depending on the system used. (see notes under horizontal accuracy). Line numbers were added to records, and unusable data at flight-line ends were discarded (as aircraft slowed and turned around). Separate recordings were correlated by time and assigned to the correct location. The exact accuracies of these processing steps may not be known. They are discussed in the sections on attribute or positional accuracies.

Logical_Consistency_Report:

The data on the original map were collected by a single contractor or group who were responsible for collecting and processing the data. The data from this survey were collected using the same instruments (magnetometers, altimeters, navigational systems) throughout the survey and were collected in a normal length of time with no long delays between survey beginning and end. Survey layout specified the conditions and specifications under which these data were collected. Standard industry practices of the time were followed in data collection and processing.

Completeness_Report: Data is complete as reasonably digitized from the original map
Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Flight Path Recovery Horizontal position of the survey aircraft used to collect data were determined by reconciling down-looking photographs (recorded on continuous-strip film) with topographic maps and orthophotoquadrangle maps. Fiducial numbers and marks, impressed on any paper strips that were recording data or added to magnetic tape records, were included as a function of time to further reconcile location with instrumentation.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

The aircraft vertical position was determined using the navigational positioning equipment on the aircraft, which were radar altimeter and barometric altimeter.

Lineage:

Process_Step:

Process_Description:

Conversion of measured values to geographic position and magnetic values was performed by the processors using industry standard practices. Details are found under Horizontal_Position_Accuracy_Report, and Vertical_Position_Accuracy_Report Unless noted, conversion processes were not documented. Products may include some written documentation.

Process_Date: 1945

Process_Step:

Process_Description:

USGS digitized original map to ASCII format. USGS personnel used the software package Oasis Montaj by Geosoft, Inc., to read in the ASCII digitized data and create raster JPEG images.

Process_Date: 2008

Process_Step:

Process_Description:

Added keywords section with USGS persistent identifier as theme keyword.

Process_Date: 20201110
Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross

Contact_Position: Marine Geologist
Contact_Address:

Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598

Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: point

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: .0001
Longitude_Resolution: .0001
Geographic_Coordinate_Units: decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6,378,206.4
Denominator_of_Flattening_Ratio: 294.98

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

Airborne survey specifications These items are constant for the entire survey Project number: 0070 Project name: Worcester-Wicomico Survey flown by: U.S. Geological Survey Survey flown for: U.S. Geological Survey Approx. no. of line miles: 900 Survey height: 1000 ft Altitude method: Above Ground Flight-line spacing: 1.0 mi Flight-line direction: E-W Aircraft used: Beechcraft AT-11 Airport - arrival: unknown airport - departure: unknown Sensor tow distance: unknown Magnetometer used: unknown Data recording interval: unknown Regional field removed: none

Entity_and_Attribute_Detail_Citation:

Nettleton, L.L., 1971, Elementary Gravity and Magnetics for Geologists and Seismologists: Society of Exploration Geophysicists Monograph Series No. 1. Dobrin, M.B., 1976, Introduction to Geophysical Prospecting: New York, McGraw-Hill Book Company, Sheriff, R.E., 1984, Encyclopedic dictionary of exploration geophysics: Tulsa, OK, Society of Exploration Geophysicists.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Web site administration: U.S Geological Survey Central Publications Group

Contact_Address:

Address_Type: mailing address
Address:

Central Publications Group
USGS MS 902, Box 25046 DFC

City: Denver
State_or_Province: CO
Postal_Code: 80225-0046

Contact_Voice_Telephone: 303-236-5486

Distribution_Liability:

Although all data published on this website have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ASCII
Format_Specification:

Each line contains data in the following format, beginning with line 1 (no header included): longitude F12.4 Longitude in decimal degrees latitude F12.4 Latitude in decimal degrees mag F8.1 Magnetic value represented on map. This is the total field value with an arbitrary datum removed

Format_Version_Date: 1998

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

http://crustal.usgs.gov/geophysics/index.html for link to report

Fees: none

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Peter N Schweitzer
Contact_Organization: USGS Eastern Mineral and Environmental Resources Science Center

Contact_Position: Geologist
Contact_Address:

Address_Type: mailing address
Address: 12201 Sunrise Valley Drive
City: Reston
State_or_Province: VA
Postal_Code: 20192-0002
Country: USA

Contact_Voice_Telephone: 703-648-6533
Contact_Facsimile_Telephone: 703-648-6252
Contact_Electronic_Mail_Address: pschweitzer@usgs.gov

Resource_Description: md0070_meta.txt
Distribution_Liability:

This dataset was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: CSV
Format_Information_Content: Flight-line airborne magnetic anomaly measurements
File_Decompression_Technique: none
Transfer_Size: 0.051685333251953

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

http://mrdata.usgs.gov/geophysics/surveys/geophysics3/MD/md0070.txt

Fees: none

Metadata_Reference_Information:

Metadata_Date: 20201110
Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: USGS Crustal Geophysics and Geochemistry Science Center

Contact_Address:

Address_Type: mailing address
Address:

Magnetic and Gravity Information
U.S. Geological Survey
Box 25046 Mail Stop 964
Denver Federal Center

City: Denver
State_or_Province: CO
Postal_Code: 80225-0046

Contact_Voice_Telephone: 303-236-5652

Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

This page is <https://mrdata.usgs.gov/geophysics/surveys/waf/MD0070_META.html>