ANT 4114
Lab 3: Excavation techniques
9/17/2010
ATTENTION: In this week’s lab, we will be playing in the dirt, as archaeologists are prone to do.
WEAR CLOTHES THAT CAN GET DIRTY! Also, aspects of this week’s lab, particularly some
of the data that you collect, will carry over into next weeks lab, so it is very important that you
attend this lab or you will not be able to answer certain questions in next week’s lab! MAKE SURE
YOU HAVE READ CHAPTER 4 BEFORE FRIDAY! Also, you’ll want to be familiar with
what a stone flake looks like (See figure 8-7 in the book or go to google images and type in “lithic
debitage”) and what a potsherd looks like (again, go to google images and type in “potsherd”).
Introduction: The purpose of this week’s lab is to familiarize you with some of the excavation
techniques that field archaeologists use on a daily basis. We will divide into groups of between 3
and 4 people and each group will be given a plastic crate that has been filled with layers of different
soils. Some of these layers contain artifacts and some of the layers contain features. Your task will
be to excavate this box stratigraphically, in other words, one strat, or layer, at a time. As you go
along, you will be responsible for recording certain data for each strat, so EXCAVATE
CAREFULLY ONE STRAT AT A TIME. You will know that you are at a strat break when you
see a change in soil color/texture. The data that you are responsible for recording is on the
worksheet, so be sure to review the worksheet before lab on Friday or it will be tough to finish in
the allotted 50 minutes.
Getting Started: The first thing you should do is assign roles in the group, i.e., excavator,
screener, recorder. For each strat, I want you to change roles so that everybody gets a chance to
excavate. For each group, you only need to fill in one worksheet, and just put everybody’s name on
that worksheet. However, for the reflection questions, you will be working alone so you may need
to copy the data onto your own worksheet for later reference (don’t worry, it’s not too much data).
BEFORE YOU BEGIN EXCAVTING you need to take measurements of surface
elevation. You will be using a string with a line level on it as a vertical datum. This datum will be
the same height as the top of the box itself (it’ll be clear when you see the box). All vertical
measurement will be taken in centimeters from this datum and will hence be in the form centimeters
below datum (cmbd) (In archaeology, sometimes you measure from an arbitrary datum and
sometimes you measure from the ground surface). Once you have this data, you will begin
excavating. Your box is rectangular and will be arranged on the table lengthwise along a
north/south axis. You will bisect the soil in the box and only excavate the southern half. Use your
measuring stick to find the bisection line and score it with your trowel. Keep in mind that only half
of the box is in the unit you are excavating so ONLY REMOVE SOIL FROM THE
SOUTHERN HALF OF THE BOX (after you have excavated it completely, you will be drawing
a profile of the remaining wall, so try your best to KEEP THIS WALL IN TACT).
You will be excavating with a trowel and putting the soil into the screen. Once you pass the
soil through the screen, quickly scan for artifacts. You will record the number and type of artifacts
separately for each strat. If you encounter artifacts with the trowel, leave them in situ (where you
found them) and dust them off with the brush, because you want to record spatial data for each
artifact found in this way. These data include centimeters from south wall, centimeters from west
wall, and centimeters below datum. You will then graphically represent their location in plan view
(top down) on the grid provided. For artifacts recovered in the screen, you will loose this spatial
data. At a certain point, you will encounter a feature (see chapter 2 if you don’t know what this is).
When you do, clean it up (remove soil above and around it) and draw a scaled plan view on the grid
provided. Afterwards, attempt to excavate the feature soil, leaving the surrounding soil matrix in
tact. Then record top and bottom depth for the feature. After you excavate each strat, you will
record basal elevations and any other relevant data, and then you will switch roles and excavate the
next strat. Finally, once the entire unit is excavated, you will clean up the north wall with your
trowel and draw a soil profile of the stratigraphy on the grid provided using the datum to make
vertical measurments.
For each of the drawings (you should have two plan views and one profile) you will need to
make a legend that indicates what any symbols you may have used represent, as well as pertinent
data. For instance, if you draw a plan view of a feature, include its top and bottom depth in the
legend. If you draw a plan view of in situ artifacts, the legend should indicate at what depth they
were found. For the profile drawing, the legend will contain the soil descriptions that you already
made for each strat. Once you have finished your profile drawing, you have completed the lab.
GOOD LUCK!
Part 2: Reflection questions
1. What is a datum and why is it an important part of archaeological fieldwork?
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2. Which strat had a feature? What is a feature and how did you recognize it?
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3. Which strat had the most artifacts? What could you say about these artifacts based on their
context (were they associated or disassociated and how can you tell)?
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4. Why is it important to try to find artifacts in situ? What is the difference between finding an
artifact in situ vs. finding an artifact in the screen? How does this affect the quality of the spatial
data we recover?
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