All of us would have heard about archaeology, but the term Stratigraphy seems to be trending in the modern day archaeology world. So what exactly do we mean by Stratigraphy?. Stratigraphy, the modern term for archaeological theory and most of the modern exposure, processing and recording techniques, are based on Stratigraphy.
It can be defined as the study of the material which was deposited on the ground over time. Both the vertical and the lateral relationship of the strata, as well as its composition, are studied.
Law of superposition:
The law of superposition is one of the basic laws of stratigraphy, and it states that the layers which first got accumulated on the surface of the earth are much older when compared to the layers which got accumulated on top of that, provided the sequence has not be changed or disturbed.
Some of the stratified deposits include sediments, soils, rocks etc. You can also consider human-made pit holes and other structures as stratified deposits. The law of superposition has helped archaeologists to have a better and improved dating method.
We all know how things change with time. Archaeologists have this amazing job of studying how things change with time. They use the technique of typology, and by digging down the earth from top to down, they will be able to trace objects and even buildings of a historical site which was percent way back in time.
Many objects such as pots and other similar types of objects are often found in many sites. When the concept of typology is combined with stratigraphy and depending on the stylishness of the objects that are found, we can define the sequences of the stratigraphic layers.
The Archeological stratigraphy mostly focuses on the deposits which were made by the men who lived in the past. Geomorphologist on the other hand study about the flow of rivers, the change in its course, floods and how that affected the human population back in time. By comparing both the natural strata which are given by geomorphologist and the man-made strata given by archaeologists we are often able to calculate the depositional history and the chronological order in which each layer was deposited on the ground.
The uses of stratigraphy:
During times where societies and civilizations have no written history about them, stratigraphy proves to be a brilliant method to find out about their society and civilization. Even when there is recorded history, stratigraphy can be an excellent way to prove the written history. As per the law of superposition, the upper layers are younger, and the lower layers are comparatively older and based on the law, people are able to assign dates to the layers of deposits. But we cannot say that the layers provide accurate information. There are many factors which affect the strata and archaeologists might have to alter their calculations based on that.