Despite the image portrayed by Indiana Jones, archaeologists spend a majority of their time in the lab assessing artifacts and not out in the field excavating. Because of this, the archaeological material that they analyze must retain its physical integrity and be traceable to the place where it was excavated. In order to ensure these criteria are met, a standardized process is used to manage archaeological materials from the field to the lab.
A site assessment is performed prior to any excavation, collection, or removal of materials or artifacts. The site assessment is performed to determine how much of the site to sample or collect. Archaeologists, like those at The Ohio State University, often use sampling techniques in order limit the amount of material brought back to the lab for analysis. The site assessment is also used to segregate portions of the collection for specific handling such as special cleaning, unique testing or other protective measures.
Conservation treatments are prepared to maintain the integrity of the artifacts being collected. These treatments are limited to simply maintaining or conserving the archaeological materials throughout the collection and transportation process. The treatments are not intended to repair, clean, or consolidate the material. Conservation treatments include specialized structures used to stabilize and support a large or fragile piece as well as acid-free boxes used to collect items.
Unless excluded by the site assessment, the archaeological materials are cleaned to expose the original surface of the item. This helps in analyzing and dating the material. Cleaning also eliminates any substance that could hasten the decay of the artifact and provides a surface for labeling. The cleaning methods consist of wet, dry, chemical, and ultrasonic cleaning. In some cases, spot cleaning may be used to limit the cleaning method to only a portion of the material.
Throughout the collection and cleaning process, care is taken to ensure that the provenience information is kept with the item. Provenience is the term used by archaeologists to identify the “the specific geographic or spatial location (either in two-dimensional or three-dimensional space) where an object was found.” (reference National Park Service glossary).
Sort, catalog and label
After cleaning, the material within each provenience is sorted into broad categories (coins, bones, ceramics, etc.). A unique catalog number is then assigned to individual materials or material lots and a catalog record is created. The material or material lot is labeled with the catalog number.
The catalog record contains the catalog number, item description, material type, measurements, quantity, provenience, location, date collected, and collector. The record also includes any observations about the condition of the item, conservation treatments, or other notes pertinent to the specific material or material lot.
The archaeological material is packaged for shipment and storage. Objects are packaged and stored based on their material classification. The packaging is selected to minimize the potential for damage during transportation, long term storage, or retrieval. The type of packaging is also influenced by the anticipated access requirements for the material. Some material may require ready access for regular and on-going analysis while other material may be placed in long term storage. The type of packaging differs based on this requirement. As with other processing steps, provenience information is maintained throughout the packaging and storage activities.
From the time of collection to storage, every action taken on an archaeological material is documented in a log book or database. This continues into the lab. Every time an item is removed from storage for inspection, analysis, or test, the item’s record or catalog entry is updated.
The process used to collect and manage archaeological material helps ensure the physical integrity and historical record of the material is maintained. Trusting this process, archaeologists can rely on the material found in their lab to develop hypothesis and draw conclusions about the time and place they are researching.