Archaeological Data: How can Artifacts “Say” Anything about the Past?

by Erica D’EliaAssistant Laboratory Director

By now you’ve probably realized that CART archaeologists have recovered a lot of “stuff”, from wrought nails to ceramic sherds to glassware. Every artifact we find has to be thoroughly analyzed and documented; it can be a daunting task. You might be wondering how we make sense of data; that is, how do we take our raw data (the artifacts) and distill it into a format that is useful for analysis. The answer is threefold: cataloging, our typological system, and our database. These three parts function together to provide us with a wealth of data in a standardized format ready to answer questions about the past.

It’s often said that for every hour spent in the field, three hours are required in the lab to process the artifacts. This is because each artifact has to be carefully washed, analyzed, and cataloged. I’ve mentioned cataloging a few times now. What I mean by that is the process of examining each artifact’s various attributes (like function, manufacture technique, decorative style, color, and so on), grouping like artifacts together, and recording all of this information. None of this would be possible without our typological system. Our typological system makes us think about and record our data in particular ways. Each laboratory has different methods for cataloging. The Colchester Archaeological Research Team Lab places each artifact into predetermined categories (or fields) using three-letter codes. I often find it easiest to sort from the most general characteristics (what material is this made of?) to the most specific (how was it decorated? which part of the vessel is it?).

Let’s look at a few examples from our current excavations.

Wrought Nail2Rosehead Nail2




This object is metal so I record MET in the category field. It is a nail; ANA goes in the field for object. It’s made of iron (FER) and its manufacturing technique is hand-wrought (WRO). Now onto the specifics, this particular nail has a rose head (I can clearly see an apex and 4 planes where it was struck by the hammer during manufacture) and a pointed tip. I record RSE and PTN. It’s rusted, as most of the nails we find are, so I record that it is oxidized (OXD). I then indicate that it is whole (WHO) and that it is an historic (HIS) artifact used for architectural (ARC) purposes. If I also have another similar nail, but with a flat flared (or spatulated) tip, it has to be cataloged separately.


My second artifact is ceramic, category CER. It’s pretty small, so it could be either hollowware (bowls and cups) or flatware (plates and platters). Since I’m not sure, I record TGW (tableware/toiletware) as the object code. Its white porous body and cream colored appearance tell me it is creamware (ECR), a type of white refined earthenware (EAR). It has no decoration, so I skip over the description fields and move on to describing its appearance. I note that is has been clear glazed (CRG) and has a white body (WHB). Then I record that it as a sherd (SHE), meaning that there is glaze on both sides and that it is an historic (HIS) artifact related to kitchen (KIT) and domestic (DOM) activities.

Each catalog entry, or record, gets assigned a two-part number. The first part is its field specimen number which tells us where it was found. Each record within a field specimen is assigned a sequential number as a unique identifier in our database. Our nail is recorded as 3858.01 and the creamware as 3858.02. Later these records will be data-entered into AMAS, our Artifact Material Analysis System. This is a Microsoft Access database which allows us to store and query our data.

Cataloging Sheet

The power of AMAS is that it lets you query, or question, your data. For example, let’s say I wanted to estimate the date of our current site. I know nails and ceramics are very useful for dating because of changes in manufacture technique and style.

I specify that I want to see all records from our current site (area “C”) which are nails (ANA) and what type they are (the TT1 field). When I run the query 532 records come up. Of these one isn’t identified, 38 are square (which could be either wrought or machine cut) and 493 are wrought.

AMAS Query


I run another query on ceramics, this time asking to see all records for ECR (creamware, 1762-early 1800s), EPL (pearlware, 1775-1840), and EIW (whiteware, 1820-1900). This time there are only 71 records and all but one are creamware. Since I know that wrought nails are most common until about 1800 and creamware production begins in 1762 and falls out of favor by the early 19th century, I can conclude that our site was occupied in the mid-18th century. Of course, I could refine this further by adding more ceramic types to determine if creamware is one of the newest or oldest ceramic types present, but that’s a project for another day.

Typological systems, cataloging, and databases are all great tools for archaeologists to use, but they still require a lot of training and skill to know what kinds of questions to ask about your data and to see and interpret the patterns present.

See also: Computers & Data Management in Archaeology


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CART Biweekly Update – 14 August


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The Oyster Shell

by Jonathan BrisendineField Archaeologist

As part of the ongoing project of the Old Colchester Park and Preserve, the CART team has located several foundations to historic buildings of various types of construction material. These foundations range from crafted brick to dry laid plain slate stones. Now you may ask what does this have to do with oysters. While most people think of the oyster as an aphrodisiac, most will be surprised that in the past its shell was also used as a key ingredient in mortar. This type of mortar is called Tabby which is made by burning the oyster shell to create lime. Lime at the time was expensive and hard to acquire. The burnt shell was then combined with water, sand, ash, and other broken oyster shell fragments. Seen here is an example of this type of mortar holding a brick foundation together.


Oysters serve a dual purpose. While needed as a key ingredient to make mortar they also served as a cheap and readily available source of nutrition, found locally in the Occoquan and Potomac Rivers. Because of this it was highly popular to use tabby in the majority of buildings as just like in todays’ society the working class made up the majority of the population. Massive oyster beds can be found throughout the coastal region. It’s thanks to this wonderful creature that many of the remnants of the long forgotten structures that we find survive the test of time intact.

So here is to the oyster, not only are you delicious but you also help preserve the past for future generations to enjoy as well as acting as a natural filter to help keep our waterways clean.


To see a close up example of shell in mortar go to


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Hold History in Hand! Volunteer Archaeology


What: Archaeology New Volunteer Orientation
Purpose: To familiarize those new to archaeology to the basics of methodology and to introduce the more experienced to the Cultural Resource Management & Protection Branch.
Dates: Friday August 28 & *Saturday September 12
*check the schedule for changes, cancellations or updates
Time: 10:00 am – 2:00 pm
Location: Falls Church, VA

Sign Up! Click here

No experience is required. Must be 16. Under 18 must have a guardian sign up with them. If none of the scheduled dates work, please let us know by writing to If there are many requests, we may be able to add another orientation.

Fairfax County offers some great perks to regularly scheduled core volunteers*. For the most updated information see Volunteering in the Parks Information.


*Subject to change. See each website for any changes in volunteer benefits or scheduling.

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Meet the Staff!!

If you would like to learn more about the CART staff and the various projects we have all worked in our years of archaeology, please check out the “Meet the Staff” page at the top or click here.

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Finding Tin-glaze

by Kayla MarciniszynSenior Field and Lab Archaeologist

1750HisCerEdtFlmRecent excavations at Site 44FX0704 in the Old Colchester Park and Preserve (OCPP) have unearthed a large number of tin-glazed coarse earthenware sherds. Tin-glazed earthenware, as the name suggests, is a ceramic that contains tin oxide in the glaze and has a very soft, buff to reddish colored paste (the body of the ceramic). The tin oxide creates a unique “M&M-like” shell over the paste when viewed in cross section and easily chips off. The glaze is most often either white or blue in color and is commonly found with a hand-painted or sponged decoration in various colors. Production of tin-glazed coarse earthenware in Europe began in sixteenth century and continued until the early nineteenth century. The ware was produced all over Western Europe and has a variety of names depending on the country of origin. For example, the term “Delftware” is used for Dutch tin-glazed, “Faience” for French, and “Majolica” for Spanish.


English or Dutch tin-glazed usually has a lighter, buff colored paste while Spanish and French tin-glazed often has a reddish paste. In the Middle Atlantic, tin-glazed earthenware is common to colonial period sites and is usually assumed to be either Dutch or English made. Dutch tin glaze is more common earlier in the colonial period and English varieties more common in the later colonial period, particularly from the eighteenth century onward.

The decorations found on tin-glazed earthenware are often diagnostic and therefore a great way to determine the time period of a site. The sherds found on the site on OCPP are decorated with both blue hand-painted and purple sponged decorations. Hand-painted decorations can be diagnostic depending on the motif or the design but some have been difficult to determine during cataloging due to the small size of the ceramic fragment. Tin-glazed with a sponged decoration has been useful in narrowing the more broad production range of the coarse earthenware; according to Jefferson Patterson Park Museum, sponged tin glaze has a production range of 1708 to 1786 with peak popularity between the years of 1730-1760. Coupled with the production dates of creamware we have uncovered on the site and the absence of pearlware, we can most likely date Site 44FX0704 occupation from the mid to late eighteenth century.

Further Readings:

Tin-glazed Earthenware – Jefferson Patterson Park and Museum

Ceramic Type Collection – Historical Archaeology at the Florida Museum of Natural History

Tin-Glazed Earthenware – The Port Tobacco Archaeological Project


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Day of Archaeology!!

Today is the International Day of Archaeology.  Check out the website here or click on the image below to see archaeology happening all over the world, so many interesting sites and peoples.  We will be adding some information to the site, so others can see CART in action.


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