Owning or managing a historic site is a daunting and expensive task. One must maintain the historic structure and any new infrastructure, drawing on limited funds that are also needed for staff salaries, interpretative programming, collections management, and more. But there’s something else to add to the list: Property owners, stewards, and managers should consider the possibility that archeological resources are present on site, and strive to preserve and protect those resources.
Taking archeology into account is essential for complete preservation and interpretation of a historic site. The reality is that, because of the need for modern amenities and infrastructure, ground-disturbing activities will occur. The key to striking a balance between preservation and progress on a site is to develop a plan before beginning any construction or maintenance project.
Including Archeology in Project Planning
The character of a historic site includes not only the architecture, grounds, and landscaping but also the soil strata contained beneath the surface. Soil layers and the artifacts contained within are significant components of a historic site, just as a keystone, earthwork, or planting can be crucial to defining the historic character of the site.
Frequently, however, the need for construction and maintenance requires disturbing the ground. While this may be necessary, many stewards do not realize that even minimal ground disturbances hold the potential to destroy not only artifacts and the interpretive potential for the site, but may also irreparably alter the historic character of the site. Even seemingly innocuous activities such as the burial of phone lines and simple landscaping can destroy the site’s subsurface character, resulting in the destruction of the archeological record.
Although archeological interests and construction (or mitigation) requirements may appear to be incompatible, they don’t need to be. Successful cooperative planning efforts can take into account all interests involved. This happens at James Madison’s Montpelier, National Trust Historic Site in Virginia, and Poplar Forest, Thomas Jefferson’s Virginia retreat, as two notable examples. Both sites have on-staff archeologists who are essential to a multi-disciplinary, cooperative approach to planning and preservation.
However, for sites without the resources or need for on-site archeologists, stewards must understand that archeology is an essential component for preservation and maintenance of the site’s historic character. For example, if a historic home is suffering from water infiltration through its foundation, an obvious part of the solution is to consult historic architects or structural engineers. Not so obvious, however, is to consult an archeologist. In addition to providing interpretation of the depositional history at the site, an archeologist can assist architects and engineers by providing deliberate excavation of the foundation, isolating problem areas for repair. Following excavation, the archeologist can also determine whether additional excavation is even necessary for future repair. In this way, archeology, architecture, and engineering are not mutually exclusive in solving the problem.
Why doesn’t this kind of collaboration happen more often? The appearance of incompatibility is largely due to an incomplete understanding of archeological goals and methodology.
The Importance of Context
Archeological method and theory involves more than the search for artifacts. Archeology is the search for the information that artifacts within their depositional context can yield.
Unfortunately, the perception is that archeology is a frivolous expense with very little return value to the practical considerations at the site. Archeology is frequently viewed as one of two extremes—either a neverending thrill ride as depicted in the Indiana Jones films or as methodical, expensive excavation by students with trowels “playing in the dirt.” This is largely because the value of archeology is often only understood in terms of recovered artifacts discovered at a particular site.
Artifacts are significant and often stand alone in terms of their importance to the understanding and interpretation of a given site. Individual artifacts can yield a wealth of specific information, including but not limited to dating a site and providing a clue to the identity of the people who discarded the artifact. However, frequently more important than the artifact itself is the “context” in which the artifact is discovered. Context includes such information as the artifact’s spatial orientation, its relation to other artifacts, and its relation to soil layers.
For example, stains within a layer of soil (i.e., “features”) can often yield even more insight into the site’s occupants than artifacts alone. At one historic site, stains revealing 200-year-old fencing surrounding slave quarter sites suggested that slaves had been able to maintain a small private area away from the overseer’s prying eyes. These features were found in shallow soils that could have easily been destroyed by even the most minor ground-disturbing activities. Valuable insight into these slaves’ lives could have been lost.
Understanding that archeology is concerned with context, not just artifacts, is a vital first step in realizing why even small ground disturbances can have a significant effect on the historic character of a site. With better knowledge of archeological theory and methods, stewards will more readily understand why they should consider archeology and strive to protect archeological resources that may be present.
General Archeological Evaluation
One fundamental archeological principle is to preserve undisturbed archeological resources in situ. Oftentimes the best option is simply to do nothing. This reasoning goes to the very nature of archeological excavation. Archeology is a destructive process. The very sample with which the archeologist is working is totally and irreparably destroyed by excavation. Years of deposition and accompanying human behavior cannot be replaced, only reconstructed.
If a subsurface examination is necessary, there are nondestructive options available. The use of remote sensing methods — roton magnetometers, seismic sensors, and electrical resistivity (among other techniques) -- is commonplace and frequently employed to determine if subsurface features are present, and then to pinpoint their location and evaluate them. In some cases, remote sensing can nullify the need to excavate at all.
If, however, excavation or mitigation proves necessary, site stewards must consult with the archeologist prior to excavation to determine who should do the work and how and where excavated artifacts, if any, will be preserved and curated. The archeologist will then follow a process similar to that listed below to determine the nature and significance of archeological resources that may be present. For convenience, archeologists frequently describe archeological investigation as consisting of stages or phases.1
Phase I: This stage is when the “adventure” of archeology frequently begins. (Having tromped miles through swampland and poison ivy dodging snakes and alligators, in retrospect, I question as to exactly what the adventure was!) Phase I comprises basic survey and mapping with accompanying surface collection and subsurface testing used to determine the presence or absence of sites of interest. Preliminary information developed from Phase I survey as to the site’s age, size, and integrity frequently dictates whether a Phase II or III excavation is warranted. This information can even be used to develop an archeological management plan for a property. Phase I is the least expensive form of archeology, with costs dependent upon the size of the site, topography, soil conditions, and the amount of subsurface testing required.
Phase II: During this stage archeologists frequently excavate small areas and conduct controlled surface collection to determine site integrity. Phase II is conducted on sites identified during Phase I to determine either the extent to which further investigation is necessary or if the site should be avoided during construction or mitigation. If testing results from Phase II show that the area has significant archeological potential, then Phase III will likely be recommended.
Phase III: While all three phases contribute to the understanding and interpretation of a historic site, this stage is often the most significant for complete site interpretation. Phase III is the “classic” archeology with which most are familiar. Phase III is the most costly and time-consuming phase since it may require complete or near total excavation of a site, particularly when ground disturbances will destroy all or a portion of the site. Individual soil deposits are excavated layer by layer until a sterile soil horizon devoid of human activity is encountered. While excavating the site, archeologists keep detailed records of observations and document the excavation in painstaking detail using photography, videography, and hand-drawn renditions of features and artifacts in situ. Sites, features, and artifacts are often mapped with surveying equipment. This information is typically then downloaded into accompanying software programs enabling archeologists to develop two-dimensional and three-dimensional maps of the excavation and its relationship to the surrounding area.
While archeological fieldwork is the most visible aspect of the discipline, it should be noted that nearly three times the field time and effort is spent on preliminary research, artifact identification, analysis and curation, and reporting findings from a given site.
The first and most important step for stewards is recognizing that, if at all possible, there should be little or no ground disturbing activities on site without the presence of a qualified archeologist. This is true at both rural and urban historic sites. Although one may not think of finding archeological resources in urban environments, there are cases of archeological resources preserved even in highly developed, densely populated areas. Buildings and pavement can act as a seal over which history is preserved. Two of the more remarkable examples are the slave cemetery in New York City and the Tequesta Stone or Miami Ring located in downtown Miami, both of which were discovered below the surface of lots scheduled for development.
Stewards should strive for the complete preservation of intact archeological soils and the artifacts they contain. In fact, for those with easements attached to the site, easement language could be interpreted to include archeological resources. Owners or managers could be under a legal obligation to prevent or limit ground disturbances altogether!
The reality, though, is that a complete prohibition of ground-disturbing activities is unrealistic. Site stewards should consider alternative solutions to construction or maintenance needs with the goal of preserving any intact archeological remains present on the site. If a viable, nondestructive solution cannot readily be found, remember that an archeologist may provide further options while simultaneously enhancing the understanding of the occupational history at the site.
In the event that a site needs construction or maintenance requiring ground disturbance, site stewards should be prepared to protect archeological resources. At a minimum, stewards should establish a baseline of current topographical conditions and subsurface ground disturbances that have already occurred at the site. Included in this baseline should be an evaluation of potential problem areas such as water drainage, root intrusion, heave (swelling or rising of displaced soil), or other potential immediate threats to historic structures and archeological resources. These may include but are not limited to the following. Determine:
- With current gutter and downspout configurations, where is runoff occurring? Is it being routed away from the site?
- If roads are present, is it possible that the slope or amount of road substrate compaction encourages or directs additional water runoff toward the site?
- Is a road or the structure itself acting as a dam, trapping water or preventing water flow away from the site?
- What is the overall condition of existing utility lines and can they be located?
- Are water lines or spigots contained within walls or the foundation and, if so, what are their current conditions?
- Does root intrusion from vegetation or soil heave from landscaping pose a threat to the structure or archeological resource?
Ideally, stewards should strive to move beyond this basic information and develop an archeological management plan to help guide them with construction or maintenance decisions. In addition to the above baseline information, the following questions should be addressed in developing an archeological management plan:
- Have previous archeological investigations been conducted on site? If so, what areas of the site have been investigated and what was the nature of the archeological record and site stratigraphy?
- What other ground disturbances have already occurred on site?
- Where are ground disturbances located in relation to the construction or maintenance area? If so, can new work be confined to already disturbed areas?
- If archeological excavations are undertaken, what potential impacts would soil removal have on structural integrity of building walls or foundations?
- If archeological excavations are undertaken, what resources and facilities are available to ensure the curation, preservation, and storage of recovered artifacts and field notes?
Development of even the most basic archeological management plan can prove invaluable to help stewards protect archeological resources present at the site. With the development of an archeological management plan or baseline assessment, owners and managers can properly consult with archeologists who frequently enhance site interpretation while simultaneously assisting other experts working on site. Without a arrangement plan, present archeological resources may be irreparably damaged or destroyed, resulting in a lost opportunity to gain significant insights at the historic site.
There is significant added value to this approach. First, stewards can have the confidence that they have done their due diligence and can make better decisions about construction and maintenance projects.
Second, stewards will reduce the risk of the surprise discovery of an archeologically significant site during the project. Once surprise discoveries are made, the archeological resource may have already been destroyed— the information it could have yielded may already be gone. In some cases, depending on the nature of the surprise discovery, the project may be forced to stop until reactive archeology can take place. This is bound to add costs and cause delays. The bottom line is that stewards should strive to consider archeology prior to embarking on any ground-disturbing activities at the site. The alternative could be expensive in terms of lost time, resources, and opportunities to gain additional knowledge about the site.
Not all archeologists assign the same nomenclature to this process because the reality is that the archeological process involves a mix of techniques and levels of intensity driven by finances, topography, soil conditions, and threat to the resource. Publication Date: