Please ensure you do not climb any of the stone work!
Placed with special permission from Historic England and the Friends of Lesnes Abbey.
To log this EarthCache, visitors may be required to:
1. Describe the texture, color, and condition of the Kentish ragstone at Lesnes Abbey.
2. Estimate how much of the original ragstone remains visible in the ruins.
3. Explore the significance of the stone in the abbey's construction and its medieval origins.
EarthCache Questions: ( and please note the difficulty of these questions reflects the level of difficulty of the EC )
1. Describe the texture and appearance of the Kentish ragstone found at Lesnes Abbey. How does it feel to the touch, and what is its color and general condition?
2.. What evidence of weathering can you see on the Kentish ragstone, and what factors do you think have contributed to this weathering?
3. Based on the site’s information, what period does the formation of Kentish ragstone date back to, and in what kind of environment was it formed?
4. Why do you think Kentish ragstone was chosen for the construction of Lesnes Abbey, and what advantages did it offer?
5. Please take a picture of yourself in front of the ruins, a picture of a personal item or your geocaching name on a bit of paper and include this in your log.
Kentish Ragstone: A Detailed Description for an Earthcache
Geological Formation and Composition
Kentish Ragstone is a hard, grey limestone primarily found in the county of Kent, England. It is a sedimentary rock formed from the remains of marine organisms, primarily microscopic shells and fragments of coral, that accumulated on the seabed millions of years ago. The stone is part of the Hythe Beds, a geological formation dating back to the Cretaceous period, approximately 95-100 million years ago.
The formation of Kentish Ragstone involved several stages:
- Sedimentation: The remains of marine organisms settled on the seabed, forming a layer of organic-rich sediment.
- Compaction: Over time, the weight of overlying sediments compressed the organic matter, expelling water and reducing the pore space.
- Cementation: Minerals, such as calcite, precipitated from groundwater and filled the gaps between the particles, cementing the sediment into a solid rock.
Kentish Ragstone is primarily composed of calcite (calcium carbonate), which gives it its hardness and durability. It may also contain small amounts of other minerals, such as silica and clay.
Physical Characteristics
Kentish Ragstone is characterized by the following physical properties:
- Color: Typically a light grey to dark grey color, depending on the amount of organic matter and impurities present.
- Texture: Fine-grained and relatively uniform in texture.
- Hardness: A hard stone, resistant to scratching and abrasion.
- Durability: Weather-resistant and durable, making it suitable for construction and landscaping.
- Cleavage: Tends to cleave in thin, irregular slabs due to its layered structure.
Uses of Kentish Ragstone
Kentish Ragstone has been quarried and used for centuries due to its durability and aesthetic appeal. It has been used in a variety of applications, including:
- Construction: Building stone for walls, floors, and other structures.
- Landscaping: Paving stones, garden edging, and decorative elements.
- Sculpture: A popular material for carving sculptures and monuments.
- Architectural details: Moldings, cornices, and other decorative elements.
Lesnes Abbey, located in southeast London, has an EarthCache focused on the unique geological aspects of Kentish ragstone found on its grounds. The abbey, founded in 1178, is rich in history, but it also offers a glimpse into the geological materials used during its construction.
EarthCache Description: Kentish Ragstone at Lesnes Abbey
Kentish ragstone, a durable type of limestone sourced from the geological Weald region of Kent, can be observed at Lesnes Abbey. Known for its strength and weather resistance, Kentish ragstone was frequently used in medieval construction across southeast England.
This EarthCache offers an opportunity to study the characteristics of Kentish ragstone, including:
Formation: Kentish ragstone was formed during the Cretaceous period from compacted marine sediments, mainly composed of calcite from ancient marine organisms. It is part of the Greensand formation, which gives the stone its distinctive hard texture.
Properties: Kentish ragstone is particularly valued for its durability, as well as its grayish-blue color. These properties made it a popular choice for constructing long-lasting structures like abbeys, churches, and castles.
Use in Architecture: Medieval builders prized Kentish ragstone for its ability to withstand weathering, and its use at Lesnes Abbey highlights the need for durable building materials in religious and defensive structures.
Visitors to the EarthCache are encouraged to observe the stone’s texture, color, and condition, taking note of how it has weathered over time.