"Local Geology & It's Influence on Local Development".
April 2004 Meeting Report
Guest Speaker - Dr Andy Howard
The April 2004 meeting of the Keyworth & District Local History Society was held in The Centenary Lounge, Keyworth on 2nd April 2004 and, as seems to be the order of the day now, was very well attended. Bob Hammond was officiating at his first meeting since becoming the Society’s new Chairman, (again!!). His first announcement was that the guest speaker for tonight was actually on holiday in Cyprus. However, a substitute speaker had been found at the 11th hour to step into the breach. His name was Dr Andy Howard and what a replacement!! The talk was as advertised, namely: - "Local Geology & It's Influence on Local Development".
Dr Howard began by telling the audience a little about himself. He has worked at The British Geological Survey in Keyworth since 1984 and his job is that of a Geological Mapper. One of his latest projects has been to be instrumental in producing a new geological map of Nottingham.
The presentation was in the form of a slide show with a running commentary. Dr Howard took us on a trip across the local countryside from East to West starting at Nuthall and coming over to Stanton and Keyworth. In that relatively short distance he showed us how the geology of the area changed quite dramatically. The rocks to the east were around 300 to 350 million years old whilst those that form the bedrock here in Keyworth are around 200 million years old. The nature of those rocks has played a significant role in the development of the region and why we are settled here today.
Slides were shown demonstrating how the rock strata in the region lay on a North to South bearing whilst the land sloped very gradually from the West to the East, with faults occurring in those strata on a North West to South East bearing. Under much of the region detailed were large deposits of coal and over the centuries these have been mined on a large scale. The first known mining on an organized scale was undertaken by the Willoughby family, (of Wollaton Park fame), whose fortune was built on coal. The mining was done very near the surface in simple “Bell” pits. Over the years the industry in general developed into the large-scale operation that we had until relatively recently and could be found on our own doorstep at Cotgrave Pit. During the 19th century coal mining was a very significant factor in the local economy and the area in and around Nottingham was scattered with a considerable number of small collieries.
The first rocks that we were introduced to were those at Nuthall, which were laid down in the Carboniferous period around 350 million years ago. During the Carboniferous period the region was covered by a lush, swampy, tropical rain forest and is from the residue of this material that the rocks that form the bedrock at Nuthall were formed. This rock is Magnesium Limestone and used to be quarried as Bulwell Stone and used for building purposes. Travelling eastwards the next type of rock that we meet is Lower Mottled Sandstone, which is now called Lenton Sandstone, (from the location in which it is found). This rock is very soft and easily quarried. One of its most popular uses was in the metal casting industry. It had excellent properties for moulding and was of such a good constituency that it was exported to other parts of the country. One site in Nottingham where the sandstone was quarried was alongside Derby Road between Hillside and the Queens Medical Centre.
Travelling a little further east we encounter what used to be known to all Nottinghamians as Bunter Sandstone but which the boffins have now renamed Nottingham Castle Sandstone, (it hasn’t the same ring has it?). Nottingham Castle Sandstone is somewhat harder than Lenton Sandstone and was laid down when a large shallow sea covered the area. It comprised of “reconstituted” rocks that had been washed into the sea, settled there as silt and become compacted over the millennia.
The sandstone is not really hard enough for building purposes but nevertheless central Nottingham is honeycombed with caves that have been hollowed out of the sandstone. The most notable of these are to be found at the Broadmarsh Shopping Centre where they are open to the public in the form of a tourist attraction. The British Geological Survey has helped to map the underground caves in Nottingham but there are still many whose location is unknown. Their location sometimes becomes apparent in spectacular fashion when a hole suddenly appears in the ground because the roof of the cave has collapsed. Needless to say this can have very serious, not to say, dangerous consequences. One slide that was shown illustrated an intricate carving, in the sandstone, of a scene depicting Daniel in the Lion’s Den. One location where the composition of the Nottingham Castle Sandstone can be readily studied is the tunnel that the then Duke of Newcastle had built under The Ropewalk and College Street to gain access to Derby Road from The Park Estate.
The Nottingham Castle Sandstone is a very good natural aquifer and its water retention properties are so good that, to this day, 30% of the local water supply is derived from these aquifers. Another property of the sandstone, which has an important consideration for Nottingham folk, is the high content of sulphates that the water in the aquifers contains. This makes the water particularly suitable for brewing purposes. Thus those inhabitants of Nottingham who have enjoyed a drop of mild or bitter beer down the years may thank the sandstone for their tasty brew!!
Travelling still further eastwards we arrive at Keyworth and the Mercia Mudstone that provides the bedrock here. The Mercia Mudstone was laid down around 200 million years ago so it is considerably “younger” than the rocks to the east of the area. The mudstone was an ideal source of clay for brick making. It wasn’t until the advent of the railways made the transportation of bricks economically viable that the industry declined in Nottingham later in the 19th century. A quarry of particular note, which was primarily for brick making, was to be found at Edwalton close to the Nottingham to Melton Mowbray railway line. One feature of the Mercia Mudstone is that the topsoil is of a very heavy clay nature. Before the advent of mechanised farming it must have been seriously hard work to plough. Contrast that with the very sandy soils to be fond where our little journey began.
Whilst most of the geology situated in our region has its origins from between 350 to 200 million years ago there are more recent deposits of a very interesting nature to be found. Most notable of these are the deposits to be found in the Trent Valley. These take the form of glacial deposits which were created some 500,000 years ago when enormous glaciers some 2 kilometres deep covered the area and extended southwards to a line approximately from the Severn estuary to the Thames estuary. Three separate glaciers traversed the region leaving their own particular deposits behind them. Thus we have the Thrussington Till, the Lias Till and the Oadby Till, all of which can be found in a 3 kilometre wide swathe through the Trent Valley. The Trent Valley itself was created when the melt water from these glaciers scoured the valley out of the surrounding landscape.
It seems hard to believe but the land where we live today has been the location for tropical rain forests, deserts, shallow seas and vast sheets of ice. All in their own peculiar way have been instrumental in shaping the environment that we find today. Today those same forces are still imperceptibly continuing to alter the landscape. Dr Howard illustrated these changes in a most illuminating and lucid manner. The presentation lasted for an hour and a quarter but was always interesting and never failed to hold the audience’s attention. Not once did Dr Howard refer to any notes, falter in his delivery or cover any ground twice. His presentation was flawless. His talk must rank with the very best presentations that the Society has enjoyed. If only all our meetings could be so interesting and well presented. Those members that were present were entertained to an evening of the most educational and enjoyable nature. What an 11th hour substitute!