Stonehenge is a world-renowned prehistoric monument located in Wiltshire, England. It consists of a ring of standing stones, each weighing up to 25 tons, arranged in a circular pattern. The monument has been a subject of fascination and speculation for centuries, with questions surrounding its purpose, construction, and history. One of the lesser-known aspects of Stonehenge is the depth of the ground beneath it. In this article, we will explore the geological history of the area, the early and modern archaeological excavations, the use of Ground Penetrating Radar (GPR) survey, and the implications of the depth of the ground at Stonehenge.
Geological history of Stonehenge area
The Stonehenge area is located on the Salisbury Plain, which is a geologically diverse region in southern England. The plains are made up of a mix of chalk, clay, and sandstone, which have been shaped by the movement of glaciers and the forces of erosion. The landscape around Stonehenge has been shaped by millions of years of geological activity, including the formation of the chalk hills and the carving of river valleys.
Early archaeology and excavation
The first recorded excavation of Stonehenge was carried out in 1620 by Inigo Jones, an English architect who was intrigued by the structure. Over the following centuries, many more excavations were carried out, with varying degrees of success and accuracy. The first systematic excavations were carried out by William Gowland in the late 19th and early 20th centuries. Gowland’s excavations revealed some of the intricate details of the monument’s construction, including the use of mortise and tenon joints to fit the stones together. However, Gowland did not explore the depth of the ground beneath the monument.
Modern archaeology and geophysics
In recent years, advances in archaeological technology have allowed researchers to explore the depths of the ground beneath Stonehenge without the need for invasive excavation. One of the most useful techniques for this purpose is Ground Penetrating Radar (GPR). GPR uses radar waves to create a map of the subsurface, revealing the presence of buried structures and geology.
Ground Penetrating Radar (GPR) survey
In 2011, a team of researchers led by the University of Birmingham conducted a GPR survey of the area surrounding Stonehenge. The survey covered an area of 12 hectares and revealed a wealth of information about the subsurface. The results showed that the area around Stonehenge had been occupied for thousands of years, with evidence of a complex network of Neolithic and Bronze Age structures.
Analysis of GPR data
The GPR survey revealed that the depth of the natural soil at Stonehenge varied between 1 and 3 meters. The variation in depth is due to the complex geological history of the area, with different layers of clay, sand, and chalk present at different depths. The GPR data also revealed the presence of several archaeological features, including pits, ditches, and postholes. These features were located at depths of between 0.5 and 2 meters.
Depth of natural soil at Stonehenge
The depth of the natural soil at Stonehenge is significant because it has implications for the construction and stability of the monument. The variation in depth may have affected the stability of the standing stones, as some of them are over 4 meters tall and weigh up to 25 tons. The depth of the natural soil also has implications for the drainage of the area, which is important for the preservation of the monument.
Depth of archaeological features at Stonehenge
The depth of the archaeological features at Stonehenge is also significant, as it provides insight into the history and development of the monument. The features revealed by the GPR survey suggest that the area around Stonehenge was used for a variety of purposes over a long period of time. There is evidence of Neolithic and Bronze Age settlements, as well as the construction of roundhouses and other structures.
Comparison with other Neolithic sites
The depth of the ground at Stonehenge is not unique among Neolithic sites. Similar variations in depth have been observed at other sites, such as Avebury and Durrington Walls. However, the use of GPR technology has allowed researchers to explore the subsurface in greater detail than ever before, revealing a wealth of new information about the history and development of Stonehenge.
Implications for understanding Stonehenge
The depth of the ground at Stonehenge provides important clues about the construction and history of the monument. The variation in depth has implications for the stability and drainage of the area, and the presence of archaeological features at different depths provides insight into the long history of human activity at the site. The use of GPR technology has opened up new avenues of research, allowing us to explore the subsurface without the need for invasive excavation.
Conclusion
The depth of the ground at Stonehenge is an important aspect of the monument’s history and construction. The use of GPR technology has allowed researchers to explore the subsurface in greater detail than ever before, revealing a complex network of structures and features. The variation in depth has implications for the stability and drainage of the area, and the archaeological features at different depths provide insight into the long history of human activity at the site. Further research using GPR and other technologies is likely to reveal more secrets about this fascinating and mysterious monument.
References
Birmingham Archaeology (2011). The Stonehenge Hidden Landscapes Project. Retrieved from https://research.birmingham.ac.uk/portal/en/publications/the-stonehenge-hidden-landscapes-project(0d08e9b3-a3c7-4c5c-8b55-4786bfb8e1f1).html
Parker Pearson, M. (2012). Stonehenge: Exploring the Greatest Stone Age Mystery. Simon and Schuster.
Parker Pearson, M., & Pollard, J. (2013). Stonehenge: A New Understanding. The Experiment.
