Introduction
    The importance of archaeological exploration is that it provides insight into the past. By nature, it can be time consuming and expensive. The application of archae-geophysical surveying, allows for rapid surveying while alleviating costs and protecting in situ cultural resources. In recent decades, improved instrumentation allows for better accuracy and on site data analysis (Kvamme, 2003).  One such analysis was carried out at Bath Nature Preserve for educational purposes by a team of six University of Akron students using two geophysical methods – resistivity and gradiometry.

Local History
    Last Glacial Retreat 15,000-10,000 BCE
    Amerindian Settlement
    European Settlement
    1795 land east of the Cuyahoga River extinguished
    Bath area owned by wealthy industrialists

Area Archaeology: The Adena
    Adena inhabited area 1000 - 500 BCE
    Pioneers in farming, lithic core technology, and pottery
    Villages composed of small circular huts
    Conical shaped burial mounds

Objective
    To conduct an exploratory investigation of an area of the Bath Nature Preserve using archaeological geophysical survey methods.

Site Geology     Glacial Geology         Outwash deposits and Hiram till             deep well-drained silty clay             BNP - end moraines     Bedrock Geology         BNP - Mississippian             negligible bedrock influence     Soil Types         Ellsworth             covers most of site area             0-60 inches             silty clay, slow permeability             saturated for much of spring         Mahoning             occurs throughout better drained areas of Ellsworth soil             silty clay, slow permeability             saturated for much of spring         Bogart             south end of site             silty to sandy soil             well-drained soil     Ground Cover         Asphalt path, appears in six grid squares         Excelsior matting, secured with metal stakes                Hummocky ground         Vegetation             woody plants and long grasses

Resistivity: Geoscan model RM-15
    Specifications
        PA5 probe array, twin probe configuration
        AD1 interface, single log mode
        Gain x10
        Current 1mA
        Frequency 137Hz
        Mains Frequency 60Hz
        High Pass Filter 13Hz
        Output Voltage 40V
        15 10x10m grid squares
        Sample Interval .5m
        Traverse Interval 1m
        Traverse Pattern zigzag
    Rationale
        survey site large enough to have good variation in signal to noise
        grid size chosen for data manageability
        sampling interval chosen based on size of visible features

Processing: GeoPlot 3.0         Created master grid from field notes         Edge match            Clip         Despike         High pass filter         Low pass filter         Interpolate            Results         linear features perpendicular to slope         other linear features         area of low resistance

    Conclusions
        The linear features perpendicular to slope are most likely caused by geological processes.
        The other linear features are most likely anthropogenic in origin as they are angular.
        The area of low resistance is most likely geological and probably relates to the amount of water located in that area of the survey site.

Gradiometry: Geoscan model FM-36
   Specifications
        Resolution 0.1nT
        Range ±10nT
        Reading average OFF
        Log Zero Drift OFF
        Average period 16 readings
        Baud rate 2400
        Grid size 10m and 20m
        External trigger encoder
        Check offset OFF
        Log interval 0.125m
        Traverse interval 1m
        Traverse pattern zigzag and parallel
    Rationale
        Five grid squares of 10x10m, stripping evident, so three 20x20m grid squares used for the rest of the data.

Processing: GeoPlot 3.0         Master grid compiled from field notes.         Clip +/-3 standard deviations         Search and Replace         Zero Mean Traverse         Despike         Low Pass Filter         Clip at 5nT         Interpolate      Results         dipoles         weak, negative rectilinear feature         weak, negative semi-circular anomalies         weak, positive evenly spaced anomalies         positive anomalies

    Conclusions 
        Dipoles indicate modern influence due to their orientation, strength, and similarity to known modern disturbances.
        The evenly spaced positive anomalies are also indicative of modern influence due to their orientation, spacing, and strength.
        The rectilinear feature is anthropogenic and warrants further survey.
        The evenly spaced semi-circular anomalies are of anthropogenic origin and may be evidence of a settlement.

Comparison

Results      linear feature      semi-circular feature      gradiometry high, resistivity low (circular)      gradiometry high, resistivity low (rectangular)

Conclusions

Resistivity

            The linear features perpendicular to the slope of the land may be due to varying water content within the soils of the area. These linear features may be indicative of an old footpath, or may be geological or background influence.  Linear features parallel to the slope of the land may be indicative of an old footpath.  The area of low resistivity in the northeast portion of the survey area is probably due to standing water, since the resistivity survey is highly susceptible to varying water content in the soils.  It is the belief of the team that the resistivity survey was highly affected by water content, though some features are visible and can be located both in gradiometry and resistivity.  Therefore,  features in the resistivity survey should not be heavily interpreted unless that feature is also present in gradiometry.   

Gradiometry 

            The linear features in gradiometry perpendicular to the slope are most likely geological features due to their size and water content. This may be evidence of soil leaching. Geometric linear features are likely anthropogenic in origin. It is a possibility that these linear features connect north of our survey area.

            The five evenly spaced anomalies may be post molds.  This feature suggests prior occupancy of the Adena Culture, who built circular living quarters using posts as the main structural support. The posts were placed in a circular pattern and ranged from 6-18 meters in diameter, which is the approximate diameter of the circular anomalies. The anomalies appear on the gradiometry survey because the Adena may have burned their villages after leaving an area. The effect of burning would leave a stronger magnetic signature in the subsurface from the reduction of iron oxyhydroxides contained in the combusted organic material.

            This rectilinear feature may be indicative of a prehistoric structure not associated with the Adena Culture, who constructed round huts.  It is a possibility that the feature could be an early historic structure.  The dipoles are also suggestive of modern influence because the survey extended over the path, which likely contains pieces of metal from the construction of the path.  The dipoles in the pathway are very similar to the ones found outside the pathway, suggesting that the strong dipoles outside the path are modern in nature.  Two of the dipoles are oriented in opposite directions, meaning that one of the dipoles had been displaced at some point in time, so are not authigenic in nature.

            The linear point anomalies are of equal size and are evenly spaced, and are located in the southwest corner of the survey site. Due to the similarities in size, shape, signal strength, and spacing, the data suggests that the anomalies are modern or late historic. The linear point features in the southwest corner may indicate an old metal fence or remnants of marker flags from another study at the Bath Nature Preserve

Comparison of Results

            Shared similarities between the data sets are apparent. There is a northwest trending linear feature on both sets of data; the intersecting northeast trending line is also visible. The large resistivity low corresponds to a large area of high gradiometry readings in the southeast corner of the survey area.  Semi-circular features in the gradiometry and resistivity reading are either due to soil variations or fluctuations in water content.

The large resistivity low corresponds to a large area of high gradiometry readings in the southeast corner of the survey area.

 

Thanks
    Team Bravo would like to thank our professors Dr. Tim Matney, Dr. Lisa Park, and Dr. Linda Barrett, Dr. Linda Whitman for her earlier research, and Ann Donkin for her help in analysis. We would also like the thank the Bath Nature Preserve for allowing us to use their land.

Further Research
    For further research or more information, please see the books and websites below or contact the site master.

Bath Township 2004. [http://www.bathtownship.org/parks/page5.html]

Bloetscher, V.C., 1980, Indians of the Cuyahoga Valley and Vicinity.  The North American Indian Cultural Center, Inc.:  Akron, Ohio.  111p.

Knepper, George 2002 The Ohio Lands.

Kvamme, Kenneth, 2003 Geophysical Surveys as Landscape Archaeology. American Antiquity 68 (3) 2003 pp 435-457 The Society of American Archaeology

Hansen, Michael 1999. The History of Lake Erie. Ohio Department of Natural Resources,

Division of Geological Survey.

Herz, Norman and Ervan G Garrison, Geological Methods for Archaeology. Norman Herz & Ervan G. Garrison, Oxford U Press, 1998.

Ohio Department of Transportation 2004. Ohio Byways  [http://www.ohiobyway.org/]

Schmidt, J.J., 1979 Groundwater Resources of Summit County, Ohio Department of Natural Resources

Otto, M.P., 1968, Ohio’s Prehistoric Peoples.  Ohio Historical Society: Columbus, Ohio. 

The Plain Dealer October 27, 2002 Ohio Scenic Byways “A Step Back in Time”

U. S. Environmental Protection Agency 2004 [http://www.epa.gov/surf]

Vietzen, R.C., 1965, Indians of the Lake Erie Basin or Lost Nations.  Ludi PrintingCompany:  Wahoo, Nebraska.  370 p.

White, George W. 1984 Glacial Geology of Summit County Ohio. State of Ohio Department of Natural Resources Division of Geological Survey Report of Investigations Number 123.

*Stephanie Haney, Beth Hochstetler, Charlie Warino the Geologists; Ashley Heeney the Geographer; Rebecca McNeill and Jim Sutter the Archaeologists