North American Database of Archaeological Geophysics

Database Report:

Site Name: Fort Morton (Petersburg National Battlefield); Site Number: _____; County: Prince George; State: VA; Country: USA; Ownership: Federal - NPS; Landform: _____;

Date of Site: AD 1864-1865; Period Type: Historic; Culture: Euro-american; Site Type: Military Post, Battlefield; Site Size: ~14,800 sq m;

Survey Type: Ground Penetrating Radar;

Instrument: Model 3055 (120MHz); Model 3105 (180 MHz); Model 3102 (315 MHz); Model 3101 (900 MHz); Sampling Interval: 3 x 3 m; Prospecting Depth: 0.1-1 m; 0.2-3 m; Area Surveyed: 27,871 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

A high frequency (315 MHz) antenna GPR profile over the trenches of the bombproofs at Fort Morton;	Radar echoes of the Bombproof;
GPR profiles of the Iron detail;

Survey Type: Magnetic-Total Field;

Instrument: _____; Sampling Interval: 0.3 m; 0.8 m; Prospecting Depth: 1-1.5 m; Area Surveyed: 27,871 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

Contour map of the Fort Morton magnetic survey (2.5, 10, and 100 nT contours);	A surface plot of the magnetic field at Fort Morton;
A smoothed magnetic contour map of the Bombproof detail;	Magnetic contour maps of the Iron detail (100 nT contour interval);
Magnetic contour map showing objects behind the main fortification trench;

Survey Type: Magnetic Gradiometry;

Instrument: _____; Sampling Interval: _____; Prospecting Depth: 1-1.5 m; Area Surveyed: 81 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

Survey Type: Electromagnetic Conductivity;

Instrument: Geonics EM31, EM38; Sampling Interval: 7.6 m; 1.5 m; 0.3 m; Prospecting Depth: 6 m; 1.5 m; Area Surveyed: 27,871 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

A smoothed EM38 conductivity map of Fort Morton;	A smoothed EM38 conductivity map of the Bombproof detail;
The EM31 conductivity of the Trench detail. This map reveals a lateral gradient and a line of lows near E500;	EM31 and EM38 conductivity maps of the small Iron detail;

Survey Type: Magnetic Susceptibility;

Instrument: Geonics EM38; Sampling Interval: _____; Prospecting Depth: _____; Area Surveyed: 81 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

Survey Type: Resistivity;

Instrument: _____; Sampling Interval: 0.5 x 1.5 m; Prospecting Depth: 1.5 m; Area Surveyed: 1,326 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

A smoothed resistivity map of the Bombproof detail;	A surface map of electrical resistivity;
A smoothed resistivity map of the Trench detail;	A resistivity contour map of the Iron detail;

Survey Type: Self-Potential;

Instrument: Homemade "Flower Pot" CU-CuSO4 electrodes; Tinker and Rasor CU-CuSO4 electrodes; Ag-AgCl electrodes; Sampling Interval: 0.3 m; 0.6 m; Prospecting Depth: _____; Area Surveyed: 1-30.5 m transect; 1-15 m transect; 81 sq m; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

Soil voltages at the Iron detail;	A self-potential profile across the main fortification trench;
A self-potential profile across the Bombproof detail;	A self-potential map made over the Iron detail area;

Survey Type: Seismic Refraction;

Instrument: _____; Sampling Interval: _____; Prospecting Depth: 1.5 m; Area Surveyed: 1-30.5 m transect; 1-15 m transect; Date of Survey: 24-Jan-1991 to 3-April-1993; Land Cover Type: Grassy Field, Woods; Ground Truthing: Yes;

Graphics/Imagery:

Examples of seismic signals at Fort Morton;	A seismic recording from 12 geophones;
Seismic refraction travel time at the Bombproof shelter;

Project Name: Fort Morton (Petersburg National Battlefield), VA;

Reference: Bevan, B.W. (1996). Geophysical Exploration for Archaeology, Volume A: Archaeological Questions and Answers. Geosight Technical Report Number 4.

Bevan, B.W. (1998). Geophysical Exploration for Archaeology: An Introduction to Geophysical Exploration. Midwest Archeological Center Special Report No. 1. United States Department of the Interior, National Park Service, Midwest Archeological Center, Lincoln, Nebraska.

Survey by: Bruce W. Bevan, Geosight;

Survey for: U.S. National Park Service;

Report Location: Midwest Archeological Center, Lincoln, NE; Report Type: Technical/CRM Report;

Abstract/Summary