Norwich Cathedral: Historical and Geological Overview.
Opening times:
7:30am to 6:30pm, every day.
No admission fee, but donations are most welcome.
Well behaved dogs allowed.
[AI was used for research, but nothing on the cache page is copied from AI.]
(The published coords are for the first question now as of 17/10/25)
Logging Tasks:
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- Make your way to the front of the visitor centre/gift shop. Compare the stone used in the older archway with that used in the newer wall - what differences do you notice in color, layering, or erosion?
- Look at the cathedral’s exterior walls—can you identify a sign of chemical and of physical weathering and where?
- (Optional) Take a photo of yourself outdide or inside the cathedral with the building visible showing either yourself, your Geocaching username, or GPS coordinates at the time of your visit. This will help authenticate your visit if your answers aren't enough or aren't clear. Photos inside the cathedral are permitted, but please keep within their photography guideline here.
History:
Norwich Cathedral was founded in 1096 by Bishop Herbert de Losinga, who moved the episcopal seat from Thetford. Built in the Norman style, its original Romanesque architecture remains visible in the nave and transepts. The cathedral’s iconic spire—added in the 15th century—rises to 96 metres, making it the second tallest in England. The cloisters, begun in 1297, are among the largest in the country. Over nine centuries, the cathedral has withstood rebellion, Reformation, and restoration, serving as a spiritual and civic centre.
Geology:
The cathedral’s core structure uses local flint and mortar, typical of East Anglian geology. Its pale facing stone is Caen limestone, imported from Normandy, via medieval trade routes. Norwich sits atop chalk and flint beds shaped by glacial activity, which also influenced the River Wensum’s course beside the cathedral.
Caen Limestone: Origins and Properties
Caen stone is a Jurassic oolitic limestone, formed around 167 million years ago during the Bathonian Age. It originated in shallow marine lagoons near what is now Caen, Normandy. The stone is composed of oolites—tiny spherical grains of calcium carbonate that accumulated in warm, agitated waters. These grains were cemented together over time, forming a fine-grained, homogeneous rock ideal for carving, hence its use in building.
Key features:
- Light creamy-yellow colour
- Uniform texture with minimal fossil inclusions
- Softness when freshly quarried, hardening upon exposure
- Excellent for detailed sculpture and ashlar masonry
Caen limestone was quarried from open pits and later underground mines.
What Is Weathering?
Weathering is the breakdown of rocks in place—without moving them. It is not erosion, which involves movement of particles.
Mechanical Weathering: Breaking Without Changing
Mechanical weathering involves the physical breakdown of rocks without altering their chemical composition. It’s driven by forces like temperature, pressure, and abrasion.
• Freeze-Thaw Action:
Water enters cracks, freezes, expands, and forces the rock apart. This is common in temperate climates with fluctuating temperatures.
• Thermal Expansion:
Rocks heat up and expand during the day, then contract at night. Over time, this cycle causes stress fractures.
• Salt Crystallization:
Saltwater seeps into pores. As it evaporates, salt crystals grow and exert pressure, flaking the surface.
• Abrasion:
Wind, water, or ice physically scrape rock surfaces, wearing them down like sandpaper.
Field signs: Look for jagged edges, angular fragments, and piles of broken rock at the base of slopes or walls.
Chemical Weathering: Changing the Chemistry
Chemical weathering alters the internal structure of the rock. It’s driven by reactions between minerals and environmental agents like water, oxygen, and acids.
• Carbonation:
Rainwater absorbs CO₂, forming carbonic acid. This dissolves calcium carbonate in limestone, creating smooth, pitted surfaces.
• Hydrolysis:
Acidic water breaks down silicate minerals, turning hard rock into clay.
• Oxidation:
Oxygen reacts with iron-rich minerals, forming rust-like stains and weakening the rock.
Field signs: Look for rounded edges, softened textures, and honeycomb-like patterns—especially in limestone or sandstone.
Logging Tasks:
-
- Make your way to the front of the visitor centre/gift shop. Compare the stone used in the older archway with that used in the newer wall - what differences do you notice in color, layering, or erosion?
- Look at the cathedral’s exterior walls—can you identify a sign of chemical and of physical weathering and where?
- (Optional) Take a photo of yourself inside or outside the cathedral with the building visible showing either yourself, your Geocaching username, or GPS coordinates at the time of your visit.
- If your answers are very far from correct and you have not provided a picture, your log will be deleted. This will help authenticate your visit if your answers aren't enough or aren't clear. Photos inside the cathedral are permitted, but please keep within their photography guideline here.
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If you would like to add to the Church Micro series yourself then please visit
http://churchmicro.co.uk/
There is also a Church Micro Stats & Information page that can be found at
http://www.15ddv.me.uk/geo/cm/index.html
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