Lawrence University

On November 1, 2022 Lawrence University conducted a geophysical survey on the eastern side of Morrill Cemetery (BPT-0021) in the Town of Stockton, Portage County, Wisconsin. High-resolution magnetic data were collected over a 30 meter by 60 meter grid to determine if unmarked interments were present in the cemetery. The survey identified a number of magnetic anomalies that appear to be consistent with the presence of unmarked interments. It is recommended that any ground disturbance in the cemetery proceed under the expectation that interments might be disturbed

Peregrine, Peter N.

Lawrence University 
Lux 
Archaeological Reports Anthropology Department 
1-2023 
Geophysical Survey of Morrill Cemetery, Town of Stockton, 
Portage County, WI BPT-0021 
Peter N. Peregrine 
Follow this and additional works at: https://lux.lawrence.edu/archaeological_reports 
 Part of the Archaeological Anthropology Commons 
© Copyright is owned by the author of this document. 
This Archaeological Report is brought to you for free and open access by the Anthropology Department at Lux. It 
has been accepted for inclusion in Archaeological Reports by an authorized administrator of Lux. For more 
information, please contact colette.brautigam@lawrence.edu. 
 
 
LAWRENCE UNIVERSITY 
ARCHAEOLOGICAL REPORTS 
NUMBER FOURTEEN 
 
 
 
 
JANUARY 2023 
 
PETER N. PEREGRINE, DIRECTOR 
 
  
 
 
 
 
 
Geophysical Survey of Morrill Cemetery, Town of 
Stockton, Portage County, WI 
BPT-0021 
 
Peter N. Peregrine, Lawrence University 
January, 2023 
 
Final Report 
Wisconsin PLP#22-1547 
Abstract: 
 
On November 1, 2022 Lawrence University conducted a geophysical survey on the eastern side 
of Morrill Cemetery (BPT-0021) in the Town of Stockton, Portage County, Wisconsin.  High-
resolution magnetic data were collected over a 30 meter by 60 meter grid to determine if 
unmarked interments were present in the cemetery.  The survey identified a number of magnetic 
anomalies that appear to be consistent with the presence of unmarked interments.  It is 
recommended that any ground disturbance in the cemetery proceed under the expectation that 
interments might be disturbed. 
 
  
 
 
 
 
 
 
Contents 
 
Introduction and Context ................................................................................................................ 1 
Methods........................................................................................................................................... 1 
Results of Investigations ................................................................................................................. 2 
Recommendations ........................................................................................................................... 3 
References ....................................................................................................................................... 4 
Figures............................................................................................................................................. 5 
Figure 1: General location of Morrill Cemetery (BPT-0021) within the State of Wisconsin.................................... 5 
Figure 2: USGS 7.5 minute quad image showing the location of BPT-0021, Morrill Cemetery. ............................. 6 
Figure 3: Aerial image of Morrill Cemetery, showing lot lines. ............................................................................... 7 
Figure 4: Aerial image showing the geomagnetic survey area (outlined in yellow). ................................................ 8 
Figure 5: Geomagnetic data superimposed on an aerial image of Morrill Cemetery. ............................................... 9 
Figure 6: Geomagnetic anomalies that appear consistent with possible interments (identified with green dots). .. 10 
Figure 7: A 1938 aerial photograph of Morrill Cemetery showing trees that are no longer present. ...................... 11 
Figure 8: The location of inactive wells (blue dots) in the area around Morrill Cemetery.  The cemetery itself is in 
the center of the image. ........................................................................................................................................... 12 
Figure 9: Geomagnetic anomalies superimposed on an aerial image of Morrill Cemetery.  The purple dashed lines 
mark areas where the geomagnetic field of subsurface deposits made it difficult to identify more subtle anomalies.
 ................................................................................................................................................................................. 13 
 
 
 
 
 
 
 
 
1 
 
Introduction and Context 
 
The research reported here was undertaken by the request of the Town of Stockton, Portage 
County, Wisconsin.  The Township owns and manages Morrill Cemetery, located in the 
northwest quarter of the southwest quarter of the southwest quarter of Township 23, Range 9 
East, Section 30 (Figures 1 & 2).  The cemetery is typical of a township cemetery, covering an 
area of roughly 60 meters East-West by 160 meters North-South, and containing roughly 153 
marked interments dating from 1832 to 2009 (Figure 3).  The Town of Stockton requested a 
geophysical survey of the cemetery because there is a large area in the center of the cemetery 
that has very few marked interments, even though, being an older part of the cemetery, there 
should be many.  In addition, there are numerous broken headstones removed from their 
locations, so it is clear some interments no longer are properly marked.   
 
Methods 
 
Geomagnetic survey was conducted over two 30 meter by 30 meter grids covering the area 
where possible unmarked internments were thought to be located (Figure 4).  Geomagnetic data 
were collected using a Geoscan FM256 differential gradiometer (Geoscan Research 2009).  This 
instrument consists of two magnetometers arranged one atop the other with a 0.5 meter 
separation.  Each magnetometer measures the earth’s magnetic field and the difference between 
the two readings, which is equivalent to the vertical gradient of the earth’s magnetic field, is 
recorded.  The instrument is sensitive enough to measure tiny variations in the earth’s magnetic 
field, variations that might be caused by subtle soil changes or the presence of buried materials 
(Aspinall, Gaffney, and Schmidt 2009).  For this application sensitivity of the FM256 was set at 
1.0 nanotesla, or about 1/25,000th of the earth’s total magnetic field.  Data were collected at 0.25 
meter intervals along 0.5 meter spaced parallel North-South lines and using a zig-zag method.   
 
The raw magnetic data were downloaded from the FM256 into the Geoplot 4.0 software package 
(Geoscan Research 2016).  Analyses were complicated because of a mistake made during data 
collection.  At in about the middle of collecting the southern grid the direction in which data 
were being collected was mistakenly reversed.  Before any analysis could be done those data 
points needed to be flipped back into the correct orientation, which was accomplished by cutting 
and pasting the data into a new dataset after the values in the cut portion were put in the correct 
orientation.  Once this was done analysis conducted on the data involved (in the following order) 
(1) “clipping” to remove high and low data points more than one standard deviation from the 
mean; (2) “zero mean traverse” and “zero mean grid” to balance the data values across the 
separate grids; (3) “destaggering” to bring individual transects into proper alignment; (4) “low 
pass filtering” based on a given data point’s two surrounding measurements to enhance weak 
magnetic features; and (5) “interpolation” conducted once in the X direction to make each pixel 
represent 25 square centimeters.  The image resulting from this processing is presented in Figure 
5.  Magnetic highs appear as darker grays; magnetic lows as lighter grays. 
 
 
2 
 
Results of Investigations 
 
The basic assumption underlying the interpretation of geomagnetic data is that the survey area 
has a uniform magnetic character.  Deviations from that uniform pattern suggest the presence of 
buried objects or features with a different magnetic signature.  The focus of interpretation is 
these magnetic anomalies.  Interpreting anomalies is as much an art as it is a science.  The 
analyst uses mathematical manipulation of the data and alters the color and contrast of the related 
geomagnetic map to isolate features with specific magnetic characteristics or that seem to form 
patterns of interest.  In the case of unmarked interments, the analyst looks for anomalies that are 
oblong in shape, roughly 3 meters by 2 meters in size, and oriented East-West, as these are the 
shape and orientation of most cemetery interments in the United States (Strangstad 2013).  Such 
anomalies are also expected to be arranged in linear patterns or some other regular pattern 
reflecting planned placement within the cemetery’s organizational blueprint.   
 
In addition to shape and orientation, previous research suggests that interments with a wooden 
coffin or casket (a coffin is angled toward the head and feet, while a casket is square) have a 
magnetic signature of between 5 and 15 nanotesla, compared to the surrounding soil (e.g. 
Peregrine 2016).  This magnetic signature is due to the presence of metal objects used to 
construct the coffin or casket and metal objects on the interred individual.  The decay of organic 
material can also impart a small magnetic moment to soils.  Interments in metal caskets, which 
became ubiquitous in the early 20th century (Haberstein and Lamers 2014), have much higher 
magnetic signatures, sometimes higher than the maximum reading of the FM 256 gradiometer 
(2400 nanotesla).  This makes metal caskets easy to locate, but their strong magnetic field also 
masks all other magnetic signatures in an area roughly 3 to 5 square meters around the metal 
casket. 
 
Figure 6 indicates with green dots those anomalies that appear consistent with interments.  Note 
that some of the dots mark known interments, which provides some confirmation that the 
identified anomalies are consistent with other interments in Morrill Cemetery.  That these 
anomalies are consistent with known interments does not mean such interments are actually 
present, as there are other disturbances that might cause similar anomalies.  For example, Figure 
7 shows an aerial image of Morrill Cemetery taken in 1938.  Note the large trees scattered across 
the survey area.  Some of the anomalies marked in Figure 6 may be the decayed stumps of these 
or other plantings that once grew in the cemetery.   
 
There is a very large linear anomaly running East-West through the center of the survey area, 
roughly along the Southern side of the extant access lane though the cemetery.  This linear 
anomaly is almost certainly caused by a buried metal pipe of some kind.  Farms in the area 
around Morrill Cemetery use irrigation extensively because of the sandy soils which do not 
retain water, so irrigation systems, and associated pipes, are common in the area.  Figure 8 shows 
the location of inactive wells in the area.  It is likely that the pipe running through the cemetery is 
connected to the well in the field immediately West of the cemetery.   
 
  
 
3 
 
Recommendations 
 
1. The Town of Stockton should, in consultation with the State Historical Society of Wisconsin, 
act to preserve intact the entire area within the boundaries of Morrill Cemetery. 
 
2. The Town of Stockton should, in consultation with the State Historical Society of Wisconsin, 
undertake Phase II investigations in advance of any construction, landscaping, or other ground 
disturbance within the boundaries of Morrill Cemetery. 
 
3. The Town of Stockton should, in consultation with the State Historical Society of Wisconsin, 
have additional non-invasive surveys conducted within the boundaries of Morrill Cemetery in 
order to more precisely identify and locate potential unmarked interments.   
 
 
  
 
4 
 
References 
 
David, Andrew, Neil Linford, and Paul Linford, eds. 
2008 Geophysical Survey in Archaeological Field Evaluation.  Swindon, UK: English 
Heritage. 
 
Geoscan Research 
2009 Instruction Manual, Fluxgate Gradiometer FM 256.  Bradford, UK: Geoscan Research. 
 
Geoscan Research. 
2016 Geoplot 4.0 Instruction Manual. Bradford, UK: Geoscan Research. 
 
Haberstein, Robert and William Lamers 
2014 The History of American Funeral Directing, (8th Edition).  Brookfield, WI: National 
Funeral Directors Association of the United States. 
 
Peregrine, Peter N.  
2016 "Geophysical Survey of Wisconsin Burial Site OU-0069: Grand Chute Pioneer 
Cemetery". Lawrence University Archaeological Reports 8.  
https://lux.lawrence.edu/archaeological_reports/8 
 
Strangstad, Lynette 
2013 A Graveyard Preservation Primer, (2nd Edition).  Lanham, MD: Alta Mira. 
  
 
5 
 
Figures 
 
Figure 1: General location of Morrill Cemetery (BPT-0021) within the State of Wisconsin. 
 
 
  
 
6 
 
 
Figure 2: USGS 7.5 minute quad image showing the location of BPT-0021, Morrill 
Cemetery.   
 
 
 
 
  
 
7 
 
 
Figure 3: Aerial image of Morrill Cemetery, showing lot lines.  
 
 
 
 
  
 
8 
 
 
Figure 4: Aerial image showing the geomagnetic survey area (outlined in yellow). 
 
 
 
 
  
 
9 
 
 
Figure 5: Geomagnetic data superimposed on an aerial image of Morrill Cemetery. 
 
 
 
 
 
 
  
 
10 
 
 
Figure 6: Geomagnetic anomalies that appear consistent with possible interments 
(identified with green dots).   
 
 
 
 
  
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!( !(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
 
11 
 
 
Figure 7: A 1938 aerial photograph of Morrill Cemetery showing trees that are no longer 
present.   
 
 
 
 
  
 
12 
 
 
Figure 8: The location of inactive wells (blue dots) in the area around Morrill Cemetery.  
The cemetery itself is in the center of the image.   
 
 
 
  
 
13 
 
Figure 9: Geomagnetic anomalies superimposed on an aerial image of Morrill Cemetery.  
The purple dashed lines mark areas where the geomagnetic field of subsurface deposits 
made it difficult to identify more subtle anomalies.   
 
 
 
 
 
 
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!( !(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(


English

Geophysical Survey of Morrill Cemetery, Town of Stockton, Portage County, WI BPT-0021

https://lux.lawrence.edu/artgallery_se2024/1038/thumbnail.jp

Didier, Kiara

What I Know and What I\u27d Like to Find Out - Installation View

https://lux.lawrence.edu/artgallery_se2024/1010/thumbnail.jp

Pose (back view)

https://lux.lawrence.edu/artgallery_se2024/1008/thumbnail.jp

Pose (front view)

Volume CXLII, Number 20, April 28, 2023

Volume CXLII, Number 23, May 19, 2023

Materials: Video Still
Dimensions: Variable
Project Advisor: John Shimon, Rob Neilson
Year of Graduation: 2023https://lux.lawrence.edu/artgallery_se2023/1003/thumbnail.jp

Medeiros, Astra

The Multifaceted Woman

Materials: Ceramics, Ink and Cyanotype on Muslin, and Found Objects like Glass Marbles, Pony Beads, and Healing Dirt from El Santuario de Chimayo, Chimayo, New Mexico
Dimensions: Variable
Project Advisors: Benjamin Rinehart, Brittany Sievers, John A. Shimon
Year of Graduation: 2023https://lux.lawrence.edu/artgallery_se2023/1013/thumbnail.jp

Goodman, Emma

Something Like Skipping Stones, Detail

Project Advisor: John Shimon
Year of Graduation: 2023https://lux.lawrence.edu/artgallery_se2023/1041/thumbnail.jp

Harnisch, Ethan

Exhibition View

https://lux.lawrence.edu/alumni_magazines/1120/thumbnail.jp