Alabama Archaeology: Excavation Steps

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Historic Alabama | Glossary


Archaeological Excavation Steps: 1 2 3 4 5 6 7

Step 3.

Once an archaeologist has decided to perform additional work on a site, he or she will study the distribution of artifacts based on earlier surveys and decide where to place larger test units. Test units, or excavation units, are set up by establishing a grid. This is accomplished by using a transit and measuring tape to set stakes in the ground at a set distance, such as every two meters.

Illustration by Roy S. Dickens, Jr. Reproduced from Frontiers in the Soil: The Archaeology of Georgia.
Then, string is tied to each stake forming a series of squares, or units that form a checkerboard effect over the site. These excavation units are each given a name based on their location on the site map. Every artifact is then labeled with the reference number of the unit in which it was found. This helps us remember its location, or context, once it has been removed from the ground. This also enables the archaeologists to refer to each unit by a specific name.
Illustration by Roy S. Dickens, Jr. Reproduced from Frontiers in the Soil: The Archaeology of Georgia.

Why do archaeologists dig square holes?

Square holes are more accurate to record and easier to dig in a systematic fashion, by levels, in order to determine what the stratigraphy of the site looks like. Archaeologists excavate these layers, or levels, one at a time, trying not to mix them up. This is another way of making sure the context of the artifacts remains intact. Try thinking of a site's stratigraphic layers as being like the pages of a book. A book must be read one page at a time, in the order it was written. If you try to read a book out of order, the story will not make sense. If archaeologists did not excavate a site layer by layer it would be out of order and would make no sense. Digging sloppy holes and removing artifacts without keeping good records is like tearing pages from a book; each page, or artifact, is meaningless out of its context.  

It is important to remember that when dirt and artifacts are removed from a site, they can never be put back exactly as they were found. And, while the artifacts tell us a lot about an archaeological site, their position in the ground can tell us a lot too. This is why careful excavation and accurate maps and records are so important.

Step 4

This is a picture of a profile from one of the excavation units at Site 1Ma10 in Huntsville, Alabama. The different colors of soil represent different stratigraphic zones, or levels.