Human Alteration of Soils at the Cook Historic Site in Compartment 20 in Sewanee, TN

Patrick Vestal, Deanna Wolford, Dr. Ken Smith, Dr. Sarah Sherwood, & Dr. Bran Potter Department of Forestry and Geology, Sewanee: The University of the South

Introduction

Soil and Vegetation Results

Methods Figure 1: Cook site (outlined in blue) with soil test pits 1 through 6.

Sample pH CEC (meq/100 g)

Ca (ppm)

Mg (ppm)

S (ppm)

K (ppm)

P (ppm)

Cu (ppm)

Zn (ppm)

Forest 4.5 5.0 230 31 24 40 12 1 3.0

1A 4.5 4.5 87 25 21 36 11 29.7 7.5

1B 4.9 4.7 70 17 21 27 8 10.2 3.2

2A 4.8 3.6 89 18 20 28 12 14.4 6.3

2B 5.4 3.8 172 31 15 25 7 14.1 3.7

3A 5.5 9.1 987 45 8 31 14 53.5 27.9

3B 5.6 5.7 616 31 7 28 5 23.2 3.7

4A 4.7 4.4 75 18 16 27 11 7.1 2.0

4B 4.9 3.9 118 20 19 28 7 7.1 1.4

5A 4.6 4.3 110 21 21 38 10 10.7 3.1

5B 4.8 4.1 79 18 22 29 7 38.2 8.5

6A 7.2 36.8 7006 181 14 74 19 11.7 25.3

6B 7.4 10.0 1873 47 5 36 13 6.7 2.8

Table 1: A & L Labs soil chemistry results (pH, CEC, & chemical concentrations) of each soil test pit at the Cook Site.

Discussions and Conclusions

Acknowledgements

Literature Cited

Figure 3: Soil profile of STP 6.

We would like to thank Mrs. Nicole Nunley for her assistance in making maps and printing the poster.

Figure 7: The occurrence of artifacts at each soil test pit at the Cook site represented by mass and type.

Figure 6: Generalized zinc (Zn) concentrations at the Cook site.

0

10

20

30

40

50

60

70

1A 1B 2A 2B 3A 3B 4A 4B 5A 5B 6A 6B

Sample

%

Sand (%)

Silt (%)

Clay (%)

Figure 4: The percentages of sand, silt, and clay of each soil test pit at the Cook Site.

Figure 5: The percentages of organic matter (OM) of each soil test pit at the Cook Site as measured and reported by A & L labs.

Figure 8: Representative sample of artifacts collected at STP 3.

Figure 2: Cook site (blue) and periphery (yellow) showing locations of fence, quarries, rock mounds, and a coal pile in relation to compartment 20 in Sewanee, TN.

0

20

40

60

80

100

120

140

1 2 3 4 5 6

Soil Test Pit

Mas

s (g

)

Slag

Coal

Metal

Glass

Ceramic

Bone

Lithic

0

2

4

6

8

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12

14

1A 1B 2A 2B 3A 3B 4A 4B 5A 5B 6A 6B

%

Sample

Mean OM (%) in Sewanee Soils

Total OM (%)

A&L Labs Total OM (%)

This study took place at the Cook historic site, Compartment 20, Sewanee, TN. The overall goal of the study was to assess how human occupation has changed chemical and physical soil properties.

The objectives were to: (1) Compare the site’s soil and vegetation to

that typically found in Sewanee forests. (2) Collect artifacts from soil test pits. (3) Research the site history in the

University archives.

Field Methods Two boundaries—Cook site clearing and

periphery—were mapped by GPS based on vegetation indicative of anthropogenically altered soils (Figures 1 & 2).

Historical points of interest (i.e. fence) were marked by GPS (Figure 2).

Soil samples and artifacts were collected along a transect of six Soil Test Pits (STPs) at the Cook site clearing (Figures 1 & 3).

Laboratory Methods Artifacts were washed, dried, sorted and

catalogued. The 12 soil samples were chemically analyzed

by Mehlich 3 extraction (S3M) by A & L Labs. Particle Size Analysis (PSA) were performed on

all soil samples.

• Soil texture: The abundance of silt in clearing samples compared to forest samples suggests that human occupation increased silt content relative to sand content, likely from cultivation and soil inputs (Hassan, 1978).

Organic matter: The greater abundance of organic matter in the clearing relative to common Sewanee forest soils is likely due to human inputs of discarded organic waste (Holliday, 2004).

Chemical analysis: The elevated nutrient concentrations, like zinc, at the site may be associated with wood burning, human waste, and to a lesser extent, binding with Ca and P (Aston et al. 1998; Holliday, 2004).

Site vegetation: Eastern red cedar, flowering dogwood and possibly hackberry may be associated with elevated soil pH. The persimmon snags, black cherry and hackberry may also have been managed for their fruit or nut supply (Burns and Hankala, 1990).

Artifact collection: The abundance of both

prehistoric and historic artifacts confirms the site’s long-term habitation. Bone and ceramic historic artifacts provide strong evidence that the study area was once a home site (Dr. Sherwood, personal communication).

• Soil texture: Changes in soil texture show a trend toward silt loam in clearing sites. Silt increased from 33.1% to 53.0% from sample 1A to 4B. Silt increased again from 32.8% to 47.0% from sample 5A to 6B (Figure 4).

Organic matter (OM): The highest OM

percentages were found in 6A (13.3%), 3A (9.1%), 5A (8.4 %), and 1A (8.1%); while, the lowest OM percentages were found in 6B (3.8%) and 3B (4.1%). All OM percentages were higher than the 3.5% OM mean for Sewanee upland soils (Figure 5).

Chemical analysis: Soil pH, cation exchange

capacity, and nutrients like zinc tended to have above-average concentrations in STP 3 & 6 (clearing center) when compared to forest soils, though sulfur and to an lesser extent, potassium, were divergent to this trend (Table 1 & Figure 6).

Site vegetation: The stem count for the site

was 58 living trees. The most common species were flowering dogwood (10 trees), black cherry (10), black locust (9), and hawthorn (6). Notably, (3) persimmon snags, (2) hackberry, and (2) Eastern red cedar formed a minor component of the site’s trees.

Site Description The 0.0979 hectare (0.242 acres) site and

periphery include evidence of past human occupation: five rock mounds, a fence, three quarries, and a coal pile (Figures 1 & 2).

Aston, M.A., 1998. The use of heavy metal soil analysis for archaeological surveying. Chemosphere, Vol. 37, No. 3, pp. 465-477.

Burns, Russell M., and Barbara H. Honkala, tech. coords. 1990. Silvics of North America: 1. Conifers; 2. Hardwoods. Agriculture Handbook 654. U.S. Department of Agriculture, Forest Service, Washington, DC. vol.2, 877 p.

Hassan, Ferik A. Sediments in Archaeology: Methods and Implications for Paleoenvironmental and Cultural Analysis. Journal of Field Archaeology, Vol. 5, No. 2, pp. 197-213.

Holliday, Vance T, 2004. Soils in archaeological research. New York: Oxford University Press.

• Artifact collection: Artifact concentration and diversity was greatest at the center of the site, in STPs 3 and 6, than the periphery. The most common artifact by mass (grams) was metal (69.34), followed by coal (55.64), slag (54.4), glass (52.78), lithic (52.52), ceramic (18.32), and bone (5.15). Lithic artifacts, the only prehistoric objects found at the site, consisted mostly of chert flakes, and were found in all soil test pits (Figures 7 & 8).

Artifact Results