Geology of the OUGS East Midlands Branch
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OUGS East Midlands Branch The East Midlands Branch of the OUGS is active in Derbyshire, Lincolnshire, Leicestershire, Nottinghamshire, Northamptonshire and Rutland. Each county has different geological interests and aspects. The age of exposures ranges from the young Cretaceous muds, silts and sands of eastern Lincolnshire to the ancient rocks and fossils of the Precambrian inlier in Charnwood, Leicestershire. There is much to interest OUGS members and the committee tries to organise field trips of variety and in different regions each year. Also in our area we have the National Stone Centre near Wirksworth and the British Geological Survey at Keyworth, both of which we have been able to patronise regularly. Currently we have around 87 members. We try to organise events and field trips throughout the year, these include a weekend away in October/ November (Snowflake) and a Day of Talks in December. Our Branch AGM is at the end of January. Every two or three years we also try and organise a week away in a particular location and are looking forward to Arran in April 2021 (postponed from 2020). Click on the County name to find out more about what each county has to offer. Derbyshire Derbyshire – there is much beauty and variety in the landscape and many places of geological interest in Derbyshire. Most of the county exposures are from the Carboniferous but in the south of the county are younger Triassic muds and sandstones. The Peak District National Park is famed for the white and grey stones of the White Peak Carboniferous Limestone and the Namurian sandstone known as Millstone Grit. The park’s walls, lead mining scree, roadstone quarry faces and karst exposures are littered with reef fossil corals, bivalves and brachiopods. The area is also famous for Blue John crystal and Black Ashford marble. Also in the county the Coal Measures of Westphalian age have given rise to much coal mining and extraction. Derbyshire The East Midlands Branch have been visiting Lathkil Dale with Dr Vanessa Banks to look at the river catchment geology. This is planned to continue in May 2021 Derbyshire There are Copper mines and impressive folding at Ecton Hill. We visited them on an earlier Snowflake weekend based in Hartington. Derbyshire Gritstone boulder at Baslow Edge Derbyshire Stepping through the country’s Geological periods at the National Stone Centre. This museum, visitor and research centre built in a disused quarry is also well known for the examples of stone walls from around the British Isles …….. and cake. Derbyshire Carboniferous reef limestone quarry, Wirksworth Leicestershire Leicestershire’s surface geology is mainly late Triassic mudstones and early Jurassic mudstones and limestones with little upheaval except for the complex Precambrian metamorphic inliers in the Charnwood Forest / Bradgate area. The fossil sea pen Charnia is the first known Precambrian fossil in the U.K and Bradgatia is another very early Ediacaran fossil find from the area. Leicestershire Charnwood Forest consists of outcrops of the Charnian supergroup of late Precambrian age. There are greenschist facies metamorphic strata, volcanic rocks (porphyritic dacites, andesites, lavas, ignimbrites) and sedimentary rocks (tuffs, turbidites, breccia) with several intrusive dioritic masses or inliers which stick up through Triassic mudstones. A bit of a jigsaw. Lincolnshire Lincolnshire is the second largest county in Britain and although travelling north to south there may be little change in the geology depending on what line you take from the Humber to the Wash, from east to west takes you from the coastal alluvial marshes, across boulder clays, over the Cretaceous chalk wolds across the post glacial silts and peats of the fens across the whole stratigraphical sequence of Jurassic limestones, mudstones and sandstones, across the heath and down Lincoln Edge into the Triassic Mercia mudstones of the Trent valley. A treasure trove for sentimentalists, sorry sedimentologists. Lincolnshire Limestone is found throughout the county and beyond as a building stone. Lincolnshire The Cretaceous Chalk wolds near Tetford. Red Hill is also a well known site in the wolds, just below the Carstone and renowned for its red chalk band, an indication of how sea levels have risen and fallen. Lincolnshire Salt and freshwater marsh near Friskney Lincolnshire For centuries Lincolnshire Limestone has been a significant building stone and most communities have their own nearby quarries. This is Blankney. The Branch have had past visits to the Lincoln Cathedral quarry, Ancaster Quarry and had building stones tours of Stamford and Lincoln (and Derby and Oakham). Nottinghamshire Nottinghamshire’s mainly Permo-Triassic rocks include several sites of interest to geologists. A time of deserts and coastal plains eroding and depositing sediments as the Zechstein sea responded to climatic conditions. As well as the oil and coal it is better known for, further south in the county there are gypsum deposits. This is Cresswell Crags, a magnesian limestone gorge with caves and fissures which would have been the most northerly inhabited land at the southern edge of the ice during the last Ice Age. This makes them of great archaeological interest. The 24 caves were inhabited by Neanderthals up to 50,000 years ago and frequently since. The first British examples of palaeolithic Rock art were found in 2003. It is a SSSI and an English Heritage Scheduled Ancient Monument. Nottinghamshire Pleasley Vale – dolomitised limestone near the colliery Nottinghamshire Nottingham City Centre and Castle sit on a 38m high sandstone cliff, which in recent centuries has been utilised by humans and is now a hidden maze of over 800 original sandstone caves and tunnels. The distribution of caves falls almost entirely within the Chester Formation (previously Nottingham Castle Sandstone) of the Sherwood Sandstone Group. The origins of this formation may be traced to the Triassic period (c.250-245 million years ago) when sands and gravels were deposited in a northerly flowing braided river. These fluvial deposits were buried and cemented by anhydrite, gypsum, dolomite, calcite and quartz, raised to the surface by erosion and uplift, and subjected to further weathering and erosion. The result is a thick sequence of interbedded sediments that are strikingly exposed in the interiors of caves and in several cliffs and man-made cuttings (such as the Park Tunnel). Courtesy Trent & Peak archaeology Nottinghamshire East Midlands Branch are very lucky to have had use of the National Geological Survey headquarters at Keyworth for meetings, our Days of Talks, Branch AGMs and tours of the extensive core stores as well as patronage of the shop. This image is of the The Geological Walk. It consists of natural stone paving laid out to represent the different geological time periods, with some 40 different types of rock used over the 130-metre-long concourse and the Hutton Building unconformity. Nottinghamshire 2019 was the 100 Anniversary of the UK’s first oil discovery and extraction at Hardstoft. Dr Tim Pharaoh led us round various sites in 2018 concerning oil and coal in the area. This nodding donkey is at Dukes Wood Nature reserve near Eakring. Northamptonshire Northamptonshire forms part of the great belt of Jurassic rocks that runs north-east from Dorset, via the Cotswolds and Lincolnshire to Yorkshire. Rocks of the Jurassic Period formed between 208 and 146 million years ago. Northamptonshire is not famous for its rocky outcrops, but it is possible to see what lies beneath the surface. The local building stones of its towns and villages display a great variety of material from the Lower and Middle Jurassic. These include limestones, such as Weldon stone (Lincolnshire Limestone Formation) and the Blisworth Limestone, and sandstones such as the Northampton Sand Formation. Some are oolitic, and others are rich in fossils. Some buildings are in the Northamptonshire Polychrome style, which contrasts pale limestones with varying shades of darker iron-rich stones. The high iron content of the Northampton Sand Formation is another important feature of Northamptonshire’s rocks. It was once exploited for large-scale iron ore extraction especially in the Corby, Kettering, and Wellingborough areas. St. Peter’s Church in Northampton has a memorial to William Smith, “the Father of English Geology” or “Strata Smith” who died in Northampton in 1839. His grave is in the churchyard. Northamptonshire Farthinghoe Railway Cutting RIGS site in the Marlstone sequence of calcareous ironstones and ferruginous mudstones. Branch members have been helping survey the site. Members also contribute articles to our Branch magazine, Rockhopper, which is e-mailed to members around five times a year. Northamptonshire Some buildings are in the Northamptonshire Polychrome style, which contrasts pale (often fossil- and oolite-rich) Blisworth limestones with varying shades of darker iron-rich sandstones. Rutland In England’s smallest county the oldest rocks that occur at the surface are the mudstones and limestones of the early Jurassic Lias Group. These are overlain to the east by a middle Jurassic sequence involving limestones, sandstones and mudstones of the Inferior Oolite Group and the succeeding Great Oolite Group . Empingham Dam was built in 1974 to flood the Gwash and Catmose river valleys to create Rutland Water. The reservoir is largely underlain by the Upper Lias Whitby mudstone formation of the early Jurassic . Photo: Daniel Atkinson and Aimee Tinkler Rutland Collyweston Slate is a fissile oolitic Jurassic limestone formed 140–190 Million years ago with the appearance of a foliated sandstone. It has been widely used for roofing in the county and for particular buildings worldwide as a roofing slate e.g. Cambridge University colleges. Rutland Oakham The group has been treated to Building Stone tours of several major towns in the area – often led by Dr Steve Parry – Stamford, Oakham, Derby, Lincoln. Rutland Ketton Limestone Quarry provides an extensive exposure of the middle Jurassic Bathonian age, dating to around 167 million years ago.