Rock around the Campus EarthCache
-
Difficulty:
-
-
Terrain:
-
Size: 
(other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
The bedrock geology of the Nottingham area
270 to 240 million years ago all the landmasses on Earth were joined in a super-continent known as Pangea. Here, in what was to form the UK, conditions were seriously hot and dry. Rain in highlands to the north and south of the Midlands flooded across desert areas depositing sands, gravels and pebbles many times. These were subsequently buried and cemented underneath a thick layer of mud and silt.
The first three stages of this Earthcache focus on bedrock of the Triassic period (ca 250 - 200 million years ago) in the Nottingham area, using outcrops on the University of Nottingham campus. Stage four of the Earthcache relates to a glacial erratic that is also present on the campus.
The Triassic bedrock in Nottingham largely falls into two groups, namely, the Sherwood Sandstone Group and the overlying Mercia Mudstone Group (Figure 1). The Sherwood Sandstone Group is subdivided into the Lenton Sandstone Formation below and the Nottingham Castle Sandstone Formation above. The Lenton Sandstone Formation ranges up to 30 m in thickness, while the Nottingham Castle Sandstone is around 65 m thick in the south to around 150 m in the north. The Mercia Mudstone Group is divided into five formations that are a mix of mudstones, siltstones, sandstones and halites. Though widespread in Britain, they are found especially in the East Midlands, hence the name 'Mercia' which was the Anglo-Saxon tribal kingdom of the East Midlands.
Figure 1. The bedrock geology of the Nottingham area, with a rough outline of the position of the University of Nottingham campus in red. From Bell et al. (2009) The engineering geology of the Nottingham area, UK.
Completing the Earthcache
The Earthcache brings you on a circular walk around part of the campus. There are 4 waypoints on a circuit of 1.8 miles, starting and finishing at the published co-ordinates. Each waypoint is readily accessible by foot, but not all are suitable for wheelchair users. At each waypoint you will have some questions to answer; there are seven in total. The walk will take approximately 30-40 minutes.
In order to log the cache, please e-mail us your answers via the link on our profile page. Please do not mention any of the answers in your log. Finally, we would love if you could include photos of your visit, but please do not post any photos of the rocks that could be used to work out the answers.
Waypoint 1 – Nottingham Castle Sandstone
This large west-facing cliff is made of Nottingham Castle Sandstone. It was formed mainly from river deposits but the presence of some mud flakes indicates that it also contains fine sediments from shallow lakes or even puddles.
Question 1: Estimate the height of the cliff (e.g. using the elevation reading on your GPSr).
Question 2: Describe the appearance of the sandstone making up the cliff (e.g. colour, grain size, layers).
Waypoint 2 – Lenton Sandstone
The north side of the car park has a fine exposure in an old quarry face of Lenton Sandstone. This sandstone is reddish brown in colour with some mottling, hence its old name of Mottled Sandstone. The inclined bedding indicates it may be from a sand dune origin however, there is also evidence of periodic flash floods from the presence of clay particles.
Question 3: Is this sandstone coarse-grained or finely grained?
Question 4: What colour are the mottles?
Waypoint 3 – Mercia Mudstone and Nottingham Castle Sandstone
In this area Mercia Mudstone is seen to have been down-faulted against the Nottingham Castle Sandstone, which forms an old river cliff. The reddish-brown mudstone, siltstone, and sandstone belong to the Sneinton Formation, which comprises the oldest and deepest part of the Mercia Mudstone group.
Question 5: How many large caves have been hewn out of the cliff? (You will need to walk the length of the exposure.)
Question 6: Count the number of layers (beds) in the sandstone at the waypoint co-ordinates.
Waypoint 4 – The ‘Bassingfield stone’
The ‘Bassingfield stone’ is a glacial erratic of hornblende schist. Glacial erratics are pieces of rock that differ from the size and type of rock native to the area where they are located. The erratic was transported into the East Midlands by a glacier from the southwest Highlands of Scotland, and then left behind after the glacier melted. It was originally found in a gravel pit to the east of Nottingham, and was later moved onto the university campus.
Please note that you can walk right up to the erratic. There is a path to it in the flowerbed.
Question 7: Who discovered the erratic at Bassingfield? (Please give their initials and surname)
Parking
The published co-ordinatres are for the pay and display main visitor car park on campus. We recommend this as your starting point. Campus parking restrictions are in place Monday to Friday from 9.15 am - 4.30 pm when a ticket will be needed. However the first 30 minutes with a ticket is free. Parking on campus is also free in the evenings and at weekends. More information on campus parking is available on the University website.
Additional Hints
(No hints available.)