Searching for Unmarked Graves at Historic Carter Mansion, Elizabethton, TN

Carter Mansion is a well-known historic site in Tennessee. It is estimated to have been built in the 1770s and is believed to be the oldest frame house, a house with a wooden skeleton for the base, in the state. This house was built by John and Landon Carter, father, and son respectively, who were well known influential leaders of the Watauga Settlement in the late 18th century. Prior to their arrival, the area was home to Native Americans. The aim of this research was to perform a geophysical survey of a previously unresearched area of the site, providing guidance for future development of the property. A ground penetrating radar (GPR) survey was conducted with a GSSI SIR4000 with 400 MHz antennas. Previous research was able to identify both historic and prehistoric graves in other areas of the property. This project extends this knowledge and aims to determine if there are graves associated with the headstones of the Carters on the eastern margin of the property, thus enriching the history and prehistory of the site without disturbing the grounds

History to Data: Converting Topographic Maps into Digital Elevation Models

Studying past landscapes existing before the modern era (pre-1945) carries great difficulty. Historical maps can offer insight to researchers, but the two-dimensional cartographic features on these maps remain largely inaccessible for geospatial analyses. This study investigates the idea of unlocking the data within historical maps to be utilized by Geographic Information Systems (GIS). To realize this goal, the cartographic features must be extracted and converted into digital vector (line) and raster (grid) data. For the purposes of this study, we focus on the extraction of elevation contour lines in United States Geological Survey (USGS) historical topographic maps. These lines are converted into Digital Elevation Models (DEMs), thus creating historically accurate digital landscapes. To ensure a high-quality result, the topographically derived DEMs (TOPO-DEMs) are compared to modern satellite-derived DEMs. The implications of this study can be directly applied to historical, archeological, and environmental research

Object-Based Image Analysis of Ground-Penetrating Radar Data for Archaic Hearths

Object-based image analysis (OBIA) has been increasingly used to identify terrain features of archaeological sites, but only recently to extract subsurface archaeological features from geophysical data. In this study, we use a semi-automated OBIA to identify Archaic (8000-1000 BC) hearths from Ground-Penetrating Radar (GPR) data collected at David Crockett Birthplace State Park in eastern Tennessee in the southeastern United States. The data were preprocessed using GPR-SLICE, Surfer, and Archaeofusion software, and amplitude depth slices were selected that contained anomalies ranging from 0.80 to 1.20 m below surface (BS). Next, the data were segmented within ESRI ArcMap GIS software using a global threshold and, after vectorization, classified using four attributes: area, perimeter, length-to-width ratio, and Circularity Index. The user-defined parameters were based on an excavated Archaic circular hearth found at a depth greater than one meter, which consisted of fire-cracked rock and had a diameter greater than one meter. These observations were in agreement with previous excavations of hearths at the site. Features that had a high probability of being Archaic hearths were further delineated by human interpretation from radargrams and then ground-truthed by auger testing. The semi-automated OBIA successfully predicted 15 probable Archaic hearths at depths ranging from 0.85 to 1.20 m BS. Observable spatial clustering of hearths may indicate episodes of seasonal occupation by small mobile groups during the Archaic Period

Geophysical and Archaeological Investigations of Enslaved Peoples at Cannons Point Preserve, Georgia

Geophysical and Archaeological Investigations of Enslaved Peoples at Cannons Point Preserve, Georgia Amy Sowers Collins1, Dr. Eileen G Ernenwein1, and Dr. Lindsey Cochran2, Department of Geosciences1 and Department of Sociology and Anthropology2, East Tennessee State University, Johnson City, Tennessee Cannons Point Preserve at St. Simons Island, Georgia was the site for the 2022 East Tennessee State University archaeological field school. The study area was believed to have once housed enslaved peoples at the plantation. Ground penetrating radar (GPR) and magnetometry surveys were performed at the preserve. These geophysical surveys are a common first step in archaeological research, because they can detect and map buried historic and prehistoric features prior to excavation. A real time kinematic (RTK) global navigation satellite system (GNSS) instrument was used to place stakes in the ground demarcating 10m x 10m grids for data collection. GPR data were collected using a GSSI-SIR-4000 system with a 400 MHz center-frequency antenna in south-north traverses spaced 0.5m apart. The system was set to record 100 scans per meter, 512 samples per-scan, using a 50 ns range. Magnetometry data were collected using a Bartington Grad601-2 fluxgate magnetometer in south-north traverses every 0.5m. Magnetometry collects eight readings per meter along transects. GPR data were processed using GPR-Slice software and magnetometry data were processed with ArchaeoFusion. Magnetometry anomalies that could be archaeological features were detected on the west and north side of the survey site. Two rectangular features were detected at 1-1.10m below the surface with GPR. Several linear features were also detected with GPR in the central and southeastern sections of the site. Although no test units were excavated deeper than 0.6m, some of the anomalies in the 0.3m-0.4m GPR slice were verified by excavation. Excavations in focused areas detected with magnetometry yielded ferrous (iron-containing) materials, burned pottery sherds, and burned bricks, as expected at a historic site. GPR and magnetometry successfully mapped buried archaeological features and helped direct excavations. Insight into the material possessions and living conditions of enslaved peoples on the island helps tell the history of those who were not recorded in the written record

Geophysical Survey Techniques

Book summary: In the newly revised Second Edition of the Handbook of Archaeological Sciences, a team of more than 100 researchers delivers a comprehensive and accessible overview of modern methods used in the archaeological sciences. The book covers all relevant approaches to obtaining and analyzing archaeological data, including dating methods, quaternary paleoenvironments, human bioarchaeology, biomolecular archaeology and archaeogenetics, resource exploitation, archaeological prospection, and assessing the decay and conservation of specimens [...

Frequency Domain Electromagnetic Induction: An Efficient Method for Investigating Fort Ancient Village Dynamics

Electromagnetic induction (EMI) has been used in archaeology for decades, but still lags in use and development when compared to magnetometry and ground-penetrating radar. While it has become more popular than electrical resistivity area survey, it is now less commonly used than electrical resistivity tomography. The EMI method is likely underutilized due to drift problems and a lack of multi-sensor, vehicle-towed systems capable of rapid, high-density data collection. In this article we demonstrate not only the effectiveness of EMI survey, but a case where entire villages would have remained undetected without it. At the Singer-Hieronymus Site in central Kentucky, USA, a vehicle-towed frequency domain EMI survey detected the location of plazas, residential areas, and trash disposal areas across multiple Fort Ancient villages that contained both intact and heavily disturbed deposits. Additionally, three new villages were revealed. Through this process, we discovered how Fort Ancient village dynamics may be studied through a geophysical investigation of village shape, size, and spatial organization

What Do We Gain From High-rate Digital Stacking?

Ground penetrating radar (GPR) is limited by the depth of penetration and signal-to-noise ratio (SNR), which both impact the ability to resolve subsurface features. GPR antennas are known to have limited depth penetration due to the noise and signal attenuated. The noise floor is the depth at which there is no discernable signal (Stec and Susek 2018). SNR is the comparison of desired signal to background noise, understanding that noise is any unwanted signal. Different objects in the environment can transmit frequencies that are recorded in data as background noise; this noise is considered to be external noise. Internal noise is noise which is generated by the internal components of the GPR system. Data processing such as filtering can reduce noise. Noise that occurs at the same frequency as the signal of interest, however, cannot be filtered out without also removing the signal of interest

Iron Age Transformations at Mmadipudi Hill, Botswana: Identifying Spatial Organization Through Electromagnetic Induction Survey

Mmadipudi Hill (CE 550–1200) is an Iron Age site in east-central Botswana approximately 3 km west of Bosutswe, a major Iron Age trade center at the eastern edge of the Kalahari Desert. A 5,000-m2 electromagnetic induction (EMI) survey conducted in 2011 revealed a cattle post arranged in the Central Cattle Pattern, including a central animal kraal with at least three clusters of houses flanking the eastern edge. A test trench confirmed the presence of a Taukome daga structure, possibly a house, 100–150 cm in depth. The EMI survey is one of, if not the first, archaeogeophysical surveys conducted in Botswana. It has proven invaluable as a means to understand the settlement organization and to pinpoint excavations to gain a more detailed understanding of the material culture. The perspective it offered on thorn brush fencing would not have been possible through excavation alone. Although small in scope, the test excavation yielded Taukome and Toutswe artifacts related to the larger sets of issues the Bosutswe region faced as Indian Ocean trade transformed the local political economy. The nature of the relationships between Bosutswe and its surrounding communities likely evolved due to the rise of a prestige goods economy, growing inequality, and environmental degradation around CE 1200. The occupation at Mmadipudi Hill would have immediately preceded these changes. By determining the spatial organization of Mmadipudi Hill, this article begins a crucial first step towards exploring what the local settlement pattern looked like prior to CE 1200 and understanding what the relationships among sites may have been

Extracting Topography from Historic Topographic Maps Using GIS-Based Deep Learning

Historical topographic maps are valuable resources for studying past landscapes, but two-dimensional cartographic features are unsuitable for geospatial analysis. They must be extracted and converted into digital formats. This has been accomplished by researchers using sophisticated image processing and pattern recognition techniques, and more recently, artificial intelligence. While these methods are sometimes successful, they require a high level of technical expertise, limiting their accessibility. This research presents a straightforward method practitioners can use to create digital representations of historical topographic data within commercially available Geographic Information Systems (GIS) software. This study uses convolutional neural networks to extract elevation contour lines from a 1940 United States Geological Survey (USGS) topographic map in Sevier County, TN, ultimately producing a Digital Elevation Model (DEM). The topographically derived DEM (TOPO-DEM) is compared to a modern LiDAR-derived DEM to analyze its quality and utility. GIS-capable historians, archaeologists, geographers, and others can use this method in their research and land management practices

Paleochannel or Palisade? Preliminary Geophysical Investigations of a Linear Feature at the Runion Archaeological Site, Washington County, Tennessee

Runion is a protohistoric Native American village located on the floodplain of the Nolichucky River in western Washington County. Previous archaeological excavations and radiocarbon dates suggest that the village was occupied during the mid-16th to mid-17th century. The Nolichucky River, in contrast, has been flowing through the area for millennia. Geophysical surveys are used to image the subsurface non-invasively, without disturbing protected land and/or organisms. Preliminary geophysical data collected at Runion include ground penetrating radar (GPR), electromagnetic induction (EMI), and magnetometry. These data show a linear feature surrounding the protohistoric village. Given its placement around the margins of the village, the feature could be interpreted as a fortification ditch, which is often paired with a palisade wall to defend a village from attack. The feature is also consistent with typical meandering floodplain stratigraphy, where sections of channel are often abandoned to form oxbow lakes. Over time these abandoned channels fill in and are called paleochannels. Each geophysical method measures the properties and characteristics of the linear feature, a presumed paleochannel. GPR sends electromagnetic radar waves into the ground, which reflect off different subsurface layers and are recorded as radargrams. Magnetometry measures subtle changes in earth magnetism, including the magnetization of rocks, soils, and/or ferrous objects. EMI systems transmit low frequency electromagnetic waves to measure both electrical conductivity (EC) and magnetic susceptibility (MS). Each of these instruments are used to collect data in transects and then processed to produce profiles, maps and, in the case of GPR, three-dimensional datasets of the subsurface. It is anticipated that GPR will reveal details about the stratigraphy of the linear feature. Magnetic, EC, and MS measurements will further help to interpret the GPR data by distinguishing between different types of sediments. These data may show if the feature is a paleochannel or a ditch excavated into older stratigraphic layers by village inhabitants for fortification. Ultimately, the feature will be tested with soil cores to study the sediments directly. At this preliminary stage the feature is interpreted to be a paleochannel. The stratigraphic layers revealed by GPR show a broad depression with stratigraphic layers characteristic of a paleochannel. In addition, magnetic readings are anomalously low on the eastern margin (closer to the modern river channel) and high on the western margin. This could indicate paired point bar sands and paleochannel fill, respectively. This interpretation is still tentative, however, because we have not yet integrated the EMI data, extracted soil cores, or dated the feature. Radiocarbon dates might help determine the relative age of the feature if organic carbon is present. In conclusion, preliminary data currently suggests that the structure is geological rather than archaeological. In the coming months we will collect more GPR data with different frequency GPR antennas, integrate the EMI data, and test the findings by extracting soil cores and reconstructing the stratigraphy