Blisworth Clay Formation facts for kids
The Blisworth Clay Formation is a special type of rock layer found in England. It's part of a bigger group of rocks called the Great Oolite Group. This rock layer was formed a very long time ago, during a period known as the Bathonian Stage, which was part of the Middle Jurassic period. Think of it like a chapter in Earth's history book!
Most of the Blisworth Clay Formation is made of a type of rock called mudstone. But it also has thinner layers of limestone and sandstone. You can also find small, round lumps of ironstone within it, which are called nodules. As you travel towards the southwest of England, this rock layer gradually changes into another rock formation known as the Forest Marble Formation.
Quick facts for kids Blisworth Clay FormationStratigraphic range: Bathonian |
|
|---|---|
| Type | Geological formation |
| Unit of | Great Oolite Group |
| Underlies | Cornbrash Formation |
| Overlies | Blisworth Limestone |
| Thickness | up to 10 metres (30 ft) typically 2-4 metres |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone, Limestone, Ironstone |
| Location | |
| Region | Europe |
| Country |  England |
| Extent | East Midlands |
| Type section | |
| Named for | Blisworth |
Contents
What is the Blisworth Clay Formation?
The Blisworth Clay Formation is a specific layer of rock that geologists study. It's like a page in Earth's diary, telling us about ancient environments. This formation gets its name from the village of Blisworth in England.
Where is it found?
This rock formation is mainly found in England, particularly in the East Midlands region. It stretches across parts of the country, showing where ancient seas once covered the land.
What is it made of?
The Blisworth Clay Formation is mostly made of mudstone. But it also contains other types of rocks.
Mudstone, Limestone, and Sandstone
- Mudstone is a fine-grained sedimentary rock. It forms from mud that settles in calm water, like in a quiet sea or lagoon.
- Limestone is a sedimentary rock often made from the shells and skeletons of tiny sea creatures. It suggests warmer, clearer water conditions.
- Sandstone is made from grains of sand cemented together. It forms in environments where sand is deposited, like beaches or river deltas.
Ironstone Nodules
You can also find small, round lumps called ironstone nodules within the Blisworth Clay. These nodules are rich in iron minerals. They often form when minerals gather around a central point, like a fossil or a piece of organic matter.
When did it form?
The Blisworth Clay Formation was laid down during the Bathonian Stage. This stage is part of the Middle Jurassic period.
The Jurassic Period
The Jurassic period was a time in Earth's history that lasted from about 201 to 145 million years ago. It's famous for dinosaurs! During the Middle Jurassic, much of England was covered by shallow seas. The sediments that formed the Blisworth Clay were deposited in these ancient marine environments.
How was it formed?
The rocks in the Blisworth Clay Formation were created from sediments that settled at the bottom of a shallow sea. Over millions of years, layers of mud, sand, and the remains of sea creatures built up. The weight of these layers, along with natural cements, squashed and hardened the sediments into the rocks we see today. The different types of rock (mudstone, limestone, sandstone) tell us that the environment changed over time, perhaps from deeper, muddier water to shallower, sandier areas.
