7 Steps to document a stratigraphic unit

Today we bring you this simple post with the basic steps to document a Stratigraphic Unit during the  archaeological excavation , ideal for archaeologists who are beginning in this archeology of countryside.

This is a routine proposal , a “checklist”, with the basic steps so that you don’t forget anything. Although everyone can make their own or adapt it to their needs or to the site they are excavating.
These are the minimum steps to document a Stratigraphic Unit in the field:

1. CLEANING

It is essential to identify, define and recognize the stratigraphic position of the EU .
This first step is the one that ensures that the entire documentation and excavation process is carried out correctly.
To do this, first of all, it will be necessary to clean the EU with a different type of tool or hand tool, also sometimes sweep (depending on the type of EU), and even moisten it with the help of a fumigator (some call it “chiriflu”) and make small tests (“microcatas” with the paddle or a pickaxe) to check the stratigraphic position of the level that we are going to document.

2. ASSIGNMENT OF EU NUMBER

It is usually a correlative number that we write down in the excavation notebook .
Each UE will have a unique number in the site and this number will be associated with the documentation (photos, sketches, plans) as well as the file where we will describe the unit and the furniture or samples collected from said unit.

3. PHOTO

Detail and context photographs, in order to identify and contextualize it in space .
To keep an order of the field photos that we are taking, and which are usually many, I take a photo before the number of the EU to which the photo belongs in the notebook.

Another very common option is to put a blackboard in the image that indicates this EU number.
By the way, and always remember to place the poles (for the scale) and an arrow made of laminated cardboard, plastic or wood indicating north (to guide the photo) and very important! Clean the EU and the environment well enough so that the entire photographed context appears clean .

 

4. DRAWINGS AND SKETCHES

It is important to locate the Stratigraphic Unit in space and document its extension and shape on a plane.
For this, during the archaeological excavation, a planimetric survey will be carried out , with a total station or gps , and details of the unit will be taken, in order to represent it in plan and to prepare cumulative sections of the site. Photogrammetry and sketches
can also be made in the field notebook , which will be very useful for tidying our heads and trying to understand and interpret the site.

 

5. ARCHAEOLOGICAL EXCAVATION

Once identified, delimited, cleaned, photographed and made the data collection for the planimetries, as well as sketches and how many diagrams we create convenient … finally! We can get down to work now .
Remember that the archaeological excavation process must also be clean and orderly, keeping your eyes and mind open to know how to interpret the new elements that may come to light with this excavation.

This is one of the most exciting parts of archeology but it is also a step that implies a “destruction”, since with the excavation we alter the record and we cannot go back, so it will be done with care to lose as little information as possible And, if we have made a mistake, it is time to be humble and know how to recognize it , because it will always be easier to correct possible mistakes in the moment and take the appropriate measures to avoid that a mistake made in the field corrupts the study and subsequent interpretation. stratigraphic and chronological.

6. DESCRIPTION

During the archaeological excavation and EYE and keeping the Stratigraphic Unit “present” ,  that is, always before exhausting it, we will fill in a descriptive card of the unit or a series of essential data about it in the excavation notebook .

In my opinion, it is essential to collect in said file or notebook at least the following points:

  1. a) Description. Composition, inclusions, compactness, color, if it is a horizontal positive. Factory, materials, construction system if it is a vertical positive and shape of the cut, type of walls and base if it is a vertical negative .
  2. b) Location. Within the reservoir or excavation area.
  3. c) Dimensions. Length, width and power / depth / height.
  4. d) Physical and stratigraphic relationships. In addition, if we want to carry out Harris diagrams and matrices, it will also greatly facilitate laboratory work. And, don’t forget, an interpretation or interpretation hypothesis, although later this can be reviewed in the laboratory, when we can study all the available data.
  5. e) Graphic documentation, material and samples. In the file or in the EU list itself, we can indicate if we have already taken the photo, the planimetry, the dimensions and if material and / or samples have been collected from this EU
  6. f) Date. It is convenient to write down the date in order to facilitate the location of any documentation or element associated with this unit.

7. MATERIALS AND SAMPLES

All the movable material that we collect from this unit during the archaeological excavation , as well as possible samples of earth, coals, mortars, etc., must be kept in their corresponding bag, box or boat , suitable to guarantee the correct conservation of the material (if we have doubts it is always helpful to consult with a restorer or laboratory specialist who will analyze the sample.)

Likewise, it must be correctly identified with a label indicating the name of the deposit, the EU to which it belongs and the date of collection, as well as the type of material.

It is also advisable to write down in the file, list or notebook, what materials or samples have been collected from each unit.

As in the excavation process itself, it is also important to be organized with the collection of materials , to avoid mixing ceramics, bone … from different units or confusions of different types that may arise. Therefore, the label and bag or box of material will be prepared as soon as we locate the first piece of furniture to collect. It should never be left until the end , because it can always start to rain, a gale can come … or a thousand things that can happen when you are in the field.

In addition, the material must be deposited in this place as its extraction is carried out since if we put it aside we could forget some fragments on the surface and thereby lose its context forever.

 

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