Bradgate Park - Old John
Delve into ancient sediments and how they were deposited.
Old John, the 18th Century folly sits on the highest point of the Park and is one of Leicestershire’s most famous landmarks. It is often referred to as the ‘Icon of Leicestershire’. The interpretation inside the Tower is dedicated to George Harry the 7th Earl of Stamford, his rather marvellous wife, and the racetrack they built on the Park.
The oldest geological formation within the walls of Bradgate Park is the Beacon Hill Formation, which can be viewed in the crags around Old John. you should be able to observe centi-metre scale layers within the rock formed by alternations of mudstone, siltstone, and sandstone. Within these layers can also be found the remnants of pieces of volcanic ash – suggesting a volcano wasn’t far away during its deposition around 565 million years ago.
You might also notice layers were the sediment gets finer as you go upwards – graded bedding. Also look out for soft-sediment deformation, where the layers looks more jumbled up and have lost their flat and parallel arrangement. All these features help to tell us the kind of environment these rocks were deposited in. The graded beds tell us that the sediments were laid down by turbidity currents – a kind of deep marine avalanche of mixed up sediment and water.