Case Study
Ellis Cemetery
Historic Euro-American Cemetery, Fort Bragg, North
Carolina
The Ellis Cemetery is a 19th Century Euro-American
cemetery located on what later became Fort Bragg, North Carolina.
It was one of several cemeteries surveyed by Archaeo-Physics to
evaluate geophysical methods by the Fort Bragg Cultural Resources
Program.
Ground penetrating radar (GPR) detects changes in the
electromagnetic properties of subsurface materials as reflections
of a transmitted signal. Many types of features and artifacts may
be detected, although sufficient contrast is difficult to predict
in field conditions. GPR survey may be performed in on of two ways.
Traditionally, data are collected as individual transects and displayed
as profile views. While this can provide valuable depth information,
horizontal patterning is difficult to interpret. A relatively new
technique known as time slicing may be used to construct planview
maps isolating specific depths.
Of the various geophysical methods used in archaeology,
GPR is generally the most successful because of its ability to detect
deeply buried but spatially small targets. The chief disadvantage
of the GPR is that its success is very dependent on specific site
conditions, and is very difficult to predict. In general, sandy,
homogeneous soils are ideal, while clays, silts, and rocky or heterogeneous
soils greatly reduce the chances of success. Burial practices and
preservation also affect the detectability of graves.
Survey Results:
- Number of known grave markers mapped:
18 headstones and 18 footstones.
- Known grave markers with observable signal
response: 16
- Percentage of known markers with observable
signal response: 89
- Possible graves outside current cemetery
boundary: Yes
- Estimated number of graves outside current
boundary: Impossible to determine; anomalies associated with suspected
graves are patterned but indistinct; may represent 10 or more
graves.
The signal response from known graves at this cemetery
was unusually distinct. Several anomalies (outlined in yellow) outside
of the current cemetery boundary are thought be associated with
unmarked burials. The exact number of unmarked burials is difficult
to determine. Anomalies outside the cemetery boundary are somewhat
indistinct, but appear to be aligned with rows of marked burials.
A linear alignment of anomalies to the east of the current cemetery
boundary may contain as many as 9 additional unmarked graves, and
more discrete anomalies appear immediately outside the northern
and southern boundaries.
The time slice plot shows a lack of strong response at the marked
grave of Jesse Ellis (approximately N13/E9), and a particularly
strong response from the adjacent grave of his daughter Catherine
(approximately N11.5/E9).
Examination of profile
images shows two strong reflectors at different depths at the
marked location of Catherine Ellis' Grave. This suggests that two
burials may be nearly superposed, although it might also be caused
by separate reflectors within a single burial (e.g., the top and
bottom of a coffin).
See also: Location
of Human Burials
Reference:
Jones Geoffrey, David L. Maki, and Michael Hargrave
2003 GPR Investigations Of Four Historic Cemeteries On Fort Bragg,
NC. Archaeo-Physics Report of Investigation #48.
