Over the years, USDA Natural Resources Conservation Service (NRCS) soil scientists have found themselves working closer with archaeologists in the field due to their common interest in soils. In Connecticut, the Office of State Archaeology and Connecticut NRCS have formed a partnership by working together on archaeological sites around the state. By sharing resources, skills, expertise, and knowledge this partnership has helped unravel and unearth some of Connecticut's mysteries.

Soil scientists have much to offer the archaeological community. They have a unique ability to read the landscape and describe and compare soil details, enabling them to recognize natural versus disturbed soils and the extent of disturbance in soils. Supportive work has included soil profile descriptions; testing soil reaction (pH); identifying unmarked or mismarked gravesites; and locating buried time capsules, structures, pipes, water raceways, foundations, and even the Curtiss P-40 Fighter crash site of Second Lieutenant Eugene M. Bradley. Most recently, the Connecticut State Archaeologist requested the assistance of NRCS soil scientists to complete a soil profile description and pH readings at the disinterment of Albert Afraid of Hawk and a ground penetrating radar survey in the Stonington Borough.

At the disinterment of Albert Afraid of Hawk, the soil profile description completed by NRCS soil scientists indicated the soils were formed in glacial outwash, more specifically, well-sorted loamy material over stratified sands and gravels derived mainly from granite, gneiss, and schist. The soil profile consisted of a very thick dark brown surface layer and two well-developed yellowish brown layers below due to weathering of minerals in the soil. With depth, the soil profile became dark brown in color due to enrichment of organic materials from the burial. This layer contained bones and artifacts from the coffin such as wood, nails, and handles. Below this dark brown layer was the olive brown natural soil material, which signifies the final depth of the burial. The soil reaction (pH) was moderately acid throughout the profile, ranging from pH 5.6 to 5.9. The pH of soil has the largest influence on bone decomposition, with bone decomposing rapidly in soils containing a highly acidic pH, generally a pH of 5.3 or less.

The soil scientists ultimately described a disturbed soil of the grave shaft. Disturbed soils have profiles that appear mixed with combinations of different materials found within the same layer, have truncated layers, and sometimes contain artifacts. This is in contrast to undisturbed or natural soil profiles, which contain uniform materials within each layer, continuous boundaries, and lack human artifacts.

In the grave, archaeologists found copper in the form of beads and a ring. The small bones of the left ring finger were intact close to the copper ring as well as fibers of hair and fabric around the copper bead earrings. Copper has been shown to influence microorganisms found within the soil, which can result in a much slower decomposition rate. The copper pieces in this burial clearly demonstrated their ability to help preserve parts that were in close proximity to the copper.

The use of technology has provided a major influence in archaeological studies and soil science. One such technology used extensively in the archaeological and soil science fields is the use of ground penetrating radar (GPR). At many sites in Connecticut, archaeologists know that cultural resource investigations can be improved through the combined use of GPR. Connecticut NRCS soil scientists not only have the necessary GPR equipment but the field and technical experience to operate the equipment, process the data, and interpret the findings.

GPR provides rapid, noninvasive detection of subsurface anomalies. GPR uses radar pulses to produce an image or record of subsurface features. The GPR antenna transmits high to ultra high frequency electromagnetic energy into the ground as the unit is pulled along in contact with the surface of the ground. As the radar wave hits a buried object or a boundary with different dielectric properties, the receiving antenna records variations in the reflected return signal. The amount of energy reflected back to an antenna by a buried object is a function of the contrast in dielectric properties that exists between an object and the surrounding soil. The greater and more abrupt the difference in dielectric properties, the greater the amount of energy that is reflected back to the antenna, and the more intense amplitude reflections on the radar record. The radar records can be displayed on a video screen and can be stored on a hard disk for future playback, processing, and display.

A favorable feature of GPR for archaeological investigations is its ability to detect disturbances and the intrusion of foreign materials in soils. It is dependent on favorable soil and site conditions, and as such results vary with soils and soil properties. On radar records, the depth, shape, size, and location of subsurface features may be used as clues to infer buried cultural features or natural layering versus chaotic filled trenches or excavated areas. GPR offers the horizontal and vertical resolution necessary for this type of application. The collection of ground truth data is important for correlating GPR signatures with specific underground targets or soils in a given survey. Most importantly, GPR data images do require someone with field experience to accurately interpret the findings.

Recently, GPR has been used to support a cultural resource project being carried out in cooperation with the Connecticut State Archaeologist and local town historians. The Captain Thomas Robinson Cemetery located in the Stonington Borough was established in the late 1700s and was known to have several unmarked gravesites. GPR investigations found several unmarked gravesites and a large crater in the middle of the cemetery. One of the local historians knew about the legend of the crater.

The crater was created during the Battle of Stonington in 1814, when a British bombshell was reported to have landed in the center of the cemetery. At this time, Huldah Hall was caring for her dying mother Elisabeth Hall. When her mother died in bed, they hurriedly buried Elisabeth and her bed in this crater. Huldah was also buried here with no marker until 1900 when the Children of the American Revolution erected a monument in her memory.

Meaningful partnerships, like the one NRCS and the Office of State Archaeology have, are the foundation for success. Multi-disciplinary teams and educational backgrounds bring diverse frames of reference to a subject and can spark exciting and dynamic ideas. NRCS and the Office of State Archaeology have learned that by sharing with others, you can achieve more.


This article is a reprint from the Connecticut State Museum of Natural History & Connecticut Archaeology Center's Fall 2012 Newsletter. © All rights reserved.