I want to know if there is a formula that tells you how old something is relative to how deep it is in the ground? I have heard of something called stratigraphy, but I am not certain that is really what I am looking for. Corey (17)

Hi Corey,

The simple answer to your excellent question is no, there is no formula that tells you how old something is relative to how deep it is in the ground – life would be a lot easier for archaeologists if there were. There are lots of factors that affect how deep a particular archaeological deposit is, many of them being natural. The underlying geology (rocks) and topography (how lumpy and bumpy the ground is) affects how soil is deposited on the bedrock, how and what plants grow on that soil and what happens when those plants die. Climate also plays a huge role in this. So in some locations, the bedrock might be just a few inches below the surface of the soil, which contains archaeological deposits thousands of years old. In other locations you might have to dig several feet down before you hit relatively recent archaeology. This is one thing that makes being an archaeologist so interesting – there are no easy answers!

Stratigraphy is the study of the layers of soil deposition over time, and is absolutely fundamental to understanding archaeology. The word stratum is a Latin one simply meaning ‘layer’ and is used in other contexts, not just archaeology. Layers of soil or other materials are deposited in the past in chronological order, with the oldest layer at the bottom. The fun really begins when human activity cuts through older layers – a medieval pit cut into a Roman road, for example. Understanding how the features relate to the stratigraphy and each other is the key to understanding what an archaeological site is telling you.

Abi

April 2018