3 Reasons Why Archaeologists Use Grids

A box grid excavation involves excavating a series of square ditches divided by intact vertical pieces known as balks. Sir Mortimer Wheeler pioneered the method, which Kathleen Kenyon perfected.

One of the keys to good archaeology is knowing exactly where everything was discovered on a site. Archaeologists use a grid to chart the entire site and smaller regions inside the site to make this procedure more effective.

Each square in the grid is measured and assigned a number. These squares are commonly known as units. The archaeologist may use this approach to make an accurate map and record the exact position of all the features and objects on the site.

If you want to learn more, keep reading! 

How Do You Grid An Archaeological Site?

Archaeologists use the following ways to use grids when working on a historical site. 

Dig Up The Site 

One of the most essential things an archaeologist can do before a dig is to set up a site. If a site is not adequately prepared, there may be problems throughout the process, and the findings obtained from the excavation may be incorrect. 

Grid Patterns

Archaeologists will divide a site into a grid system for charting and transmitting specific locations once they have been located and permission has been obtained. The grid serves as the map’s X and Y axes. After laying out a grid, features and artefacts are measured and drawn on the grid to map the site.

Archaeologists require measuring tapes, line levels, plumb bobs, a mathematical sensibility, and many hands to grid a site. The datum is the initial point or coordinate established on site and acts as a reference point for all subsequent coordinates. 

Data Use For Grids

The data serves as a reference point for all measurements made on the job site. The data should be placed in an area that will not be disturbed during excavation and is visible from most of the site. The sides of a square are formed by measuring two points to produce a right angle.

A line level is used to ensure that a precise distance is measured. Once the measuring tape is level, plumb bobs are used to indicate the exact place on the ground surface, followed by a nail or flag to mark the reference point.

What Methods Do Archaeologists Use To Decipher The Past?

Absolute dating methods try to specify a distinct, known span of time, such as a day, year, century, or millennium. Only a small percentage of items collected from an archaeological site can be precisely dated.

Radiocarbon dating, obsidian hydration, thermoluminescence, dendrochronology, historical records, mean pottery dating, and pipe stem dating are all used by archaeologists to establish absolute chronology. This section explains each of these approaches.

In archaeology, radiocarbon dating is a popular absolute dating method. It is based on the understanding that living creatures create their own organic matter through photosynthesis or by using atmospheric carbon dioxide. 

Many organic materials, including charcoal, shell, wood, bone, and hair, can provide radiocarbon dates. The amount of carbon dioxide in living organisms is the same as the amount in the atmosphere. The carbon 14 (C14) atoms decay at a known pace after the creature dies, having a half-life of 5,700 years.

Archaeological Research Methods

Archaeologists acquire data using a variety of methodologies, including desk-based studies, geotechnical surveys, and geophysical surveys. 

Geophysical Surveys

Geophysical surveys are an essential component of maritime archaeology studies. To finish their studies, archaeologists, like geologists, use geophysical data acquired before and during REC.

By gathering data on its physical qualities, geophysical surveys are used to generate photographs of the seabed. Many firms that specialize in this subject use marine geophysicists and geologists to gather and evaluate data.

Desk Based Assessments

Desk Based Assessments (DBA) are frequently the initial step for archaeologists when requested to examine an area for archaeology, both on land and at sea. This evaluation is necessary as part of the planning process for some operations. 

These may have an impact on archaeology beneath the earth or on the seafloor, such as establishing an offshore wind farm. It enables archaeologists to estimate the likelihood of discovering archaeology in that region based on what is currently known about that location.

A Geotechnical Survey

Archaeologists take samples from far beneath the ocean in search of buried evidence of the past. There are several geotechnical survey methods available. Several of these approaches were utilized by archaeologists during the RECs. One of these is a vibrocorer, which they utilized to gather sediment samples from the bottom.

This offers information on the many strata of deposits under the surface, as well as their nature and thickness. The vibrocorer operates on vibration. It is made up of a long tube called a core that is 80-90 mm in diameter and 5 to 6 metres long. The boat is first lowered to the bottom. When the core is steady, the motor is activated, vibrating the core into the seabed.

Considering Importance

Once the data has been gathered, archaeologists must assess the significance of the information gathered and summarize it in the final report. One of the most important jobs was to determine the significance of each known shipwreck.

There are various factors for determining a shipwreck’s historical significance. It depends on how useful it is for informing us about the past; certain ships are so valuable that they are legally protected. A shipwreck can serve as a time capsule, capturing a glimpse of technology and culture at the time it sank.

What Is The Purpose Of A Site Grid In Archaeology?

Archaeologists are compelled to document the context of any item found on the site, since the site is destroyed during excavation. Recording all materials dug is one technique to assure the preservation of the location of artifacts discovered. The initial step in this procedure is to create a site grid.


To assist planning, it is best to draw out a grid of 5 m squares on excavations. This grid is laid out on-site using grid pegs that serve as baselines for tapes and other planning instruments used in plan drafting. 

The contractor may prefer GPS-located site plans and sections in some circumstances, but the methods of putting out a site grid and, critically, linking it into a national grid are critical.

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