What’s Ironstone?

Tom Kearsley – Mineralogist

Iron is arguably the most important metallic element in the history of human technology. In the most comprehensive modern reference volume on properties, processing and use of metals – the Metals Handbook edited by Davis, 1998 – there are more pages devoted to ‘ferrous’ metals (‘irons’, steels and high performance alloys) than to all of the other metals combined.

Together with Magnesium (Mg) and Aluminium (Al), Iron (Fe) is an abundant element throughout the Solar System (Lodders, 2010), including the Earth. It was inherited from dust created by ancient giant stars, then brought together over four and a half billion years ago during the formation of the planet from the collision of asteroids and meteorites in the early Solar System. Much of the Earth’s Fe, along with Nickel (Ni) and Sulfur (S), is now in the core where it is responsible for the magnetic field of the planet. ‘Iron’ is also occasionally found on Earth’s surface as a ‘native’ metal, this may come from meteorite falls (which will not be pure Iron element, but will also contain a little Ni), and even a little can be found in some volcanic lavas. This raw material has been used by people for at least 5000 years, but it is so rare that ‘iron’ was not the most widely used metal until much later. In nature, Mg and Al readily form common minerals with Silicon (Si) and Oxygen (O), but they are not found as metals without human intervention, and they have only become widely manufactured and used in the last century.

Although now a little dated, ‘Metals in the Service of Man’ by A. Street and W. Alexander (10th edition, 1994) provides a concise and readable introduction to the sources of metals, their processing, properties and uses. An excellent and detailed explanation of how metals (including ‘irons’) came to be produced, from the earliest methods up to modern large-scale industries, can also be found in ‘A History of Metallurgy’ by R. F. Tylecote (1992). The first widespread use began with discovery that Copper (Cu), and later Tin (Sn) could be extracted relatively easily from their ore minerals, giving rise to the ‘Bronze Age’, beginning perhaps 9,000 years ago. It is likely that the discovery of ‘iron’ smelting was accidental, perhaps around 4,700 years ago, and was possibly linked to the use of Iron-rich material in production of copper. By 3,000 years ago, ‘iron’ was important in human societies, being used widely in making weapons.

To produce ferrous metal in quantity, it’s necessary to find a good supply of a suitable starting material – the ore. Fuel is required to break the ore down into elemental Iron, typically by raising it to a very high temperature, away from air. It’s also important to be able to remove a range of impurities from the molten metal. Improvements in smelting technique have long been driven by pressures of the cost of mining and transporting ore and fuel, but also reflect the availability of different types of ore. Since the Second World War a very unusual type of ore, Banded Iron Formation (BIF) has been mined in enormous quantities in Australia, Brazil, the USA and Russia (among other countries). BIF is a very peculiar sedimentary rock, deposited in ancient seas, more than two billion years ago when the atmosphere and oceans had very different behaviour to the modern world. Because it is available in large quantities (many millions of tonnes per annum) and can be processed quite easily to concentrate the content of Iron, it is now most economic to transport this ore worldwide, rather than smelting at source in areas lacking fuel. Before the use of BIF, most production usually relied upon local supplies of ore, as well as coal, coke or charcoal, and additives to help separate metal and slag. In Britain, we have no BIF, and there’s little in Europe as a whole. The history of ferrous metal production in Britain therefore reflects making do with what was available, and many different types of Iron-rich rocks (ironstones) were used as ore.

Example of 'Ironstone'

The most common natural Iron-rich materials found on the modern Earth’s surface are oxide minerals, carbonates, sulfides and fine aluminosilicates. The oxides may be loose mineral grains from weathering of igneous rocks such as basalt lavas, or may form by reaction of volcanic glass and Iron-bearing silicate minerals (such as olivine or pyroxene) with Oxygen and water, especially during tropical weathering. Two minerals are often formed : Goethite (yellow-brown oxyhydroxide, FeO.OH, about 60% Iron by weight) and Hematite (red-purple-grey oxide Fe2O3, nearly 70% Iron by weight), both contain Iron in an oxidised form, Fe3+, which is not very soluble in water. As anyone who has owned an old car will know, metallic ‘iron’ and steel are also able (and all too willing) to form similar oxidised rust! The insoluble oxyhydroxides and oxides are very widespread as tiny grains in soils, giving brown or red colouration. Accumulation in dense soil layers can produce material suitable for use as ore, but these minerals were also occasionally deposited from warm water flowing through cracks in rock, and may form patches and veins of very high grade ores, such as the red Hematite ‘kidney ore’ of Egremont in Cumbria. BIF contain mainly Hematite, in layers with silica.

However, if the tiny grains are washed away by streams and rivers until they reach still water, they can sink and become gently buried within muddy sediment in a lake, delta-front or quiet-water sea. Here they are effectively cut off from air, and as bacterial decay of organic matter in the mud proceeds, they may again lose Oxygen, releasing soluble Fe2+ ions. In freshwater, the ‘reduced’ soluble Iron may react with carbonate created by bacterial oxidation of organic matter (such as rotting leaves), and can be fixed as an insoluble carbonate mineral called Siderite (FeCO3). This often forms spherical concretions that may become flattened as the muddy layers are gradually squashed by continuing build-up of sediment above. The hardened (lithified) concretions or nodules are grey-green when broken, although may turn brown on weathering. Often found in mudstones between coal seams of Carboniferous age across Britain, these Siderite nodules (called ‘doggers’ by miners) may contain nearly 50% Iron by weight, and were an important source of ore during the Industrial Revolution of the seventeenth and eighteenth centuries.

Iron-rich mud deposited in seawater may behave differently. The oxides and oxyhydroxides again release soluble Iron as Fe2+ ions, but bacterial activity near the surface of the accumulating sediment removes Oxygen from the sulfate ions in the seawater, creating sulfide ions. This is how disturbed marine muds often come to smell of ‘rotten eggs’, the characteristic signature of hydrogen sulfide (H2S). Soluble Fe2+ reacts very quickly with sulfide ions, forming a black iron sulfide, and eventually golden Iron Pyrites (FeS2), with about 45% Iron by weight. This can be used as an Iron ore, but releases acidic sulfur dioxide fumes during processing, and requires both careful handling and large amounts of fuel. However, if deposition of mud is quite rapid, the production of sulfide can stop well before all of the soluble Fe has reacted, and more of the carbonate Siderite will then form, often becoming the main Iron-bearing mineral in shallow marine ironstones.

Iron may also be found in pale green hydrated aluminosilicate minerals (containing Al, Si and water), these are members of the Clay Mineral and Chlorite groups, called Berthierine and Chamosite, typically containing about 25% Iron by weight. How these minerals form is still not well understood, despite many studies of ancient and modern ironstones (Kearsley 1989; Young, 1989; Mücke and Farshad, 2005; Clement et al., 2019). There are probably several different origins. Some may be formed by soluble Fe reacting with the white clay mineral Kaolinite within the mud, or from insoluble Fe oxides reacting with Al and Si hydroxides. Some may form by tiny crystals growing within a slimy gelatinous blob or layer, some may grow as crystals directly from water in the mud. Strangely, these minerals also seem to favour growing in layers around a central core, making a concentric tiny egg, an ‘oolith’ or ‘ooid’. When ooids/ooliths are common within an iron-rich rock, it is described as an oolitic ironstone. It is not uncommon to find ironstones that contain aluminosilicates, Siderite, Hematite and Pyrite all together, including within ooliths/ooids – even with evidence that these minerals have replaced each other during or after deposition of the layer.

Rosedale SEM (Scanning Electron Microscopy) Minerals - copyright Tony Kearsley

Oolitic ironstones are complicated rocks (see figure above). As their content of Iron can vary a great deal, they may or may not prove to be an economic source of Iron, which may also depend upon the other materials that they contain. High contents of Calcium (Ca) may help smelting, but high Phosphorus (P) can contaminate the metal that is produced. The oolitic ironstones mined in Rosedale and around all of the North York Moors typically contain mixtures of Siderite and Berthierine, as well as Kaolinite and the Calcium carbonate mineral Calcite.

The oxide Magnetite (Fe3O4) may also be found in some oolitic ironstones, it contains over 70% Iron by weight. As the name suggests, this mineral is strongly magnetic, unlike almost all of the other Iron ore minerals. It is quite common in Mg- and Fe-rich igneous rocks (formed from molten material), and can occur in massive deposits with a very high percentage of Iron. For example, magnetite has long been mined in Sweden, and was much sought after by both Allied and Axis industries during the Second World War. Magnetite is well known to occur in rocks that have been subjected to burial heating (low grade metamorphism), probably growing as coarser crystals from iron carried through porous rock by hot water.

However, it has also been found (and almost completely mined out) in sedimentary ironstone deposits in Rosedale, it was so rich in Iron. Here its origin is still a mystery, and there have been differing interpretations of when and how it formed. There are several 19th century accounts of the discovery of magnetic ores in Rosedale (Bewick 1861; Wood, 1969; Marley 1871), as well as descriptions of these rocks in the Geological Survey Reports of Hallimond (1925) and Whitehead et al. (1952). From other evidence in the North York Moors, it doesn’t seem likely that these rocks were heated sufficiently to encourage metamorphic magnetite replacement of other minerals, and these are definitely not rocks formed from hot melt. Perhaps the peculiar setting where these sedimentary ironstones accumulated was an important factor in creating Magnetite? The earlier accounts suggested that the richest ore was found within elongate troughs, eroded into the underlying layers. Young (1994) suggested that there were indeed shallow basins where ooliths were deposited, but that the basins had been formed by fault motion at about the same time. Is it possible that stagnant water saturating the sediment within these hollows allowed Magnetite to form, replacing other more-oxidised Iron-rich minerals?

Ironstones deposited during the early part of the Jurassic Period have been extensively mined throughout England and Western Scotland, as described in Whitehead et al. (1952). There is a wider discussion of other ironstones from a broader range of ages, across England and Wales, in Hallimond (1925).

References

Bewick, Joseph 1861. Geological Treatise on the District of Cleveland, in North Yorkshire, Its Ferruginous Deposits, Lias, and Oolites; With Some Observations on Ironstone Mining. London: John Weale

Clement, A. M., Tackett, L. S., Ritterbush, K. A. and Ibarra, Y. 2019 Formation and stratigraphic facies distribution of early Jurassic iron oolite deposits from west central Nevada, USA. Sedimentary Geology 395 C Web. doi:10.1016/j.sedgeo.2019.105537.

Davis, J. R. (Ed.) 1998 Metals Handbook 2nd Edition. ASM International, Materials Park, OH 44073-0002, USA. i-xiv, 1521 pp. ISBN 0-87170-654-7.

Hallimond, A. F. 1925 Iron Ores: Bedded Ores of England and Wales. Petrography and Chemistry. Special Reports on the Mineral Resources of Great Britain. Volume XXIX. HM Stationery Office, London. p 75, plate IV fig. 14.

Hawley, D. 2019 Rosedale – the magnetic ironstone conundrum. Field Excursion Notes. The genesis of geology in York and beyond. Yorkshire Philosophical Society and Geological Society of London History of Geology Group. 25th Anniversary Meeting Thursday 24th October 2019. Downloaded on 3rd December 2020 from: https://www.ypsyork.org/wp-content/uploads/2020/02/HOGG-YPS-YORK-Rosedale-Magnetic-Ironstone-Conundrum-Oct-2019-ONLINE.pdf

Kearsley, A.T. 1989 Iron-rich ooids, their mineralogy and microfabric; clues to their origin. In Young, T.P. and Taylor, W.E.G. (Eds) Phanerozoic Ironstones. Geological Society of London Special Publication 46:141-164.

Lodders, K. 2010 Solar system abundances of the elements. In: Principles and Perspectives in Cosmochemistry. Lecture Notes of the Kodai School on ‘Synthesis of Elements in Stars’ held at Kodaikanal Observatory, India, April 29 – May 13, 2008 (Goswami, A. and Eswar Reddy, B. eds.) Astrophysics and Space Science Proceedings, Springer-Verlag Berlin Heidelberg. p. 379-417 ISBN 978-3-642- 10351-3.

Marley, J. 1871 On the Magnetic Ironstone of Rosedale Abbey, Cleveland. Transactions of the North of England Institute of Mining and Mechanical Engineers. 19, 193-199.

Mücke, A. and Farshad, F. 2005 Whole-rock and mineralogical composition of Phanerozoic ooidal ironstones: Comparison and differentiation of types and subtypes. Ore Geology Reviews 26:227–262.

Powell, J. H. 2010 Jurassic sedimentation in the Cleveland Basin: A review. Proceedings of the Yorkshire Geological Society 58:21-72.

Street, A. and Alexander, W. 1994 Metals in the Service of Man. 10th Edition. Penguin Books Ltd, London, UK. ISBN 10: 0140148892

Tylecote, R. F. 1992 A History of Metallurgy 2nd Edition. The Institute of Materials. 1 Carleton House Terrace, London. 255 pp. ISBN 0-901462-88-8.

Whitehead, T. H., Anderson, W., Wilson V., Wray, D. A. and Dunham, K. C. 1952 The Liassic Ironstones. Memoirs of the Geological Survey of Great Britain. Department of Scientific and Industrial Research, Her Majesty’s Stationery Office, London. pp 47-50.

Wood, N. 1869. On the Deposit of Magnetic Ironstone in Rosedale. Spons’ Dictionary of Engineering, Part VIII (Borings and Blasting), pp 501 – 512.

Young, T.P., 1989. Phanerozoic ironstones: an introduction and review. In: Young, T.P. and Taylor, W.E.G. (Eds.), Phanerozoic Ironstones. Geological Society of London Special Publication 46: ix-xxv.

Young, T. P. 1994 The Blea Wyke Sandstone Formation (Jurassic, Toarcian) of Rosedale, North Yorkshire, UK. Proceedings of the Yorkshire Geological Society 50:129-142.

The Yew – An Original Christmas Tree

Sam Newton – Woodland Creation Assistant

Yew links to Christmas and Christianity and back beyond into the depths of time. Like other evergreens, branches of yew were brought into people’s houses at Christmas as decoration and also as bitter reminder of the Christian Passion.

Yew trees in St Mary’s churchyard, Goathland. This churchyard contains some of the largest yew trees in the North York Moors. Copyright Sam Newton, NYMNPA.

Yew trees (Taxus baccata) are now strongly associated with churchyards. They are a connection to the old Norse and Celt beliefs that yew trees protected against bewitchment and death. Pagans celebrated the yew at the mid winter festival of Saturnalia, which later melted into Christmas. Many old churchyard yews may have been planted by church-builders, brought out of the woods and into a civilised setting. Or later on top of graves to ward off evil around the dead and provide branches to be carried on Palm Sunday and at funerals. It became a tradition without a remembrance of its origins.

There are also a number of churchyard yews predating their churches, and even Christianity. Some trees alive today in Britain are truly ancient. The Fortingall Yew in Scotland is possibly between 2,000 and 3,000 years old – a myth tells of Pontius Pilate as the son of a Roman envoy, being born beneath and playing as a child within its branches. While the Ankerwycke Yew witnessed the signing of the Magna Carta in 1215, as an already 1,000-year-old tree overlooking Runnymede meadows in Surrey.

The first few lines of ‘Lines on the Ancient Yew in Darley Church Yard’ (in Derbyshire)
By Samuel Barker

Thou art an interesting tree,
The fact’s beyond dispute,
Thy monster trunk and giant bows
And intersecting roots,
Rearing in solemn grandeur,
Thy patriarchal head,
Reigning in midnight dimness,
O’er the regions of the dead.

Male yew tree in St Nicholas’ Churchyard, Bransdale, showing the beginnings of next year’s flowers. Yew trees are dioicous, with individual plants either male or female. Copyright Sam Newton, NYMNPA.

The story of the yew tree is one of life, death, and resurrection. It was said by the noted forester and dendrologist Alan Mitchell, that “there is no theoretical end to this tree, no need for it to die”.

Yews reach such old age through an amazing ability to renew themselves and return from apparent decay. New shoots from the base can coalesce with the main trunk, while lowered branches can put down roots, and fallen trees remain alive as long as the smallest amount of root remains attached. Ancient trees can be split into several parts, and no longer look like one tree, but can go on surviving for many hundreds of years more.

St Nicholas’ Church, Bransdale, and its churchyard yew tree. Copyright Sam Newton, NYMNPA.

Death lingers in these long-lived trees, with all parts of the plant containing highly poisonous taxine alkaloids. Yet at the same time these same highly poisonous chemicals provide modern day science with anti-cancer compounds. The yew tree can regenerate us, as well as itself.

Yorkshire has a strong but somewhat forgotten link to yew trees. The ancient Celtic name for the City of York is Eborakon, which can be translated to ‘the place where the yew trees grow’, or came from the name Eburos, meaning ‘yew man’. In the North York Moors, yew trees are common in churchyards, and can occasionally be encountered in the surrounding areas.

For more information about this natural and cultural marvel have a look at the Ancient Yew Group’s website

Colouring in

David Mennear – Land of Iron Administration Assistant

Have a look at these two digitally ‘coloured in’ historic photographs of our local mining communities in the North York Moors, from 100 years ago.

Photograph by Thomas Smith, courtesy Beck Isle Museum. Photo colourised by: Photo Restoration Services.

Our first photograph (above) shows ironstone miners at Sheriff’s Pitt, Rosedale, getting ready for a day of hard labour in 1900. If you look closely you can notice the clothing they wore and the wide shovels they used for helping to move the heavy ironstone and scoop it into the tubs. From the tubs it was taken out of the mine and along to the nearby calcining kilns to remove the impurities to make it lighter to transport via rail on to blast furnaces in the wider region.

Photograph by Joseph Brotton, courtesy Ryedale Folk Museum. Photos colourised by: Photo Restoration Services.

The second photograph (above) was taken by J. Brotton on the 24 July 1903 – it’s of an almighty crash at the bottom of the Ingleby Incline railway. The incline is a 0.8 mile long stretch of rail to the moor top, which reaches a stonking 1 in 5 gradient at its steepest points. It was here that wagons were carefully drawn up and down the incline by a rope pulley system to allow the transport of ironstone from the Rosedale mines on to Teesside for processing into pig iron, before being transported and used across the country and the world.

Does the colourisation help make the people look more relatable? Does it make the scenes seem more immediate? Does it bring the communities of the 1900s to life?

Photos colourised by: Photo Restoration Services

Down in Yon Forest

Rachel Pickering – Woodland Team Leader

Deep in Cropton Forest is a very special place called High Leaf Howe. Its actually just a grassy clearing within the forest with a large mound, the ‘howe’, in one corner and a ruined house in another. Our archaeologists are probably more interested in the howe but for me it’s the ruin that is magical. I recall my grandma Ethel talking very fondly of her childhood at ‘Leaf Howe’ which was a small holding of about 20 acres on the edge of Wheeldale Moor where they grazed 20 sheep. They also had 3 cows and my grandma had hens which she sold the eggs from to help her parents pay the rent to Keldy Estate*. Her dad made besoms (brooms used in the steel works to clean the slag off the rolled steel when it was red hot) from the heather and her mother cleaned the school at Stape to make ends meet.

*The Forestry Commission acquired the freehold of the Keldy Estate in 1948 to incorporate into their Rosedale Forest holding, now named Cropton Forest.

High Leaf Howe, then. Property of Rachel Pickering.Recently I was looking into the census data for Stape and made a remarkable discovery. Not only had my grandma been born at High Leaf Howe but also her father Bertie in 1895 and his father George in 1851. Four generations of my direct descendants lived there.  During the first lockdown I was looking through some old family photos and imagine my delight when I came across a small black and white photo which had the words ‘Leaf Howe’ penned on the back! Even better I could recognise that the girl outside the house was grandma and the shy head poking out of the door was her mother Ada.

I have taken my father and my two children to see the old homestead, and although my son was more interested in climbing a nearby tree at the time I’d like to think my two will see the significance of this special place in the future.

High Leaf Howe, now. Copyright Rachel Pickering.

 

Diary of a Heritage Intern

Chris Bradley – previous Building Conservation Intern

Having completed my Masters degree at the University of York I was excited to be applying for jobs and starting a new career. After a year of applying and volunteering, I Chris in his natural habitat - Ryedale Folk Museum, Hutton le Hole.was elated to get the opportunity of an internship with the North York Moors National Park Authority.

Meeting the Building Conservation team was great, they were friendly and encouraging and offered to help in every way possible whilst of course keeping to the social restrictions in place. My mentors, Maria Calderon and Clair Shields, presented a clear desire to provide a practical opportunity for new starters in the heritage sector which is something that I have found to be limited in my time searching for work.

My main objective was developing a Conservation Area Appraisal and Management Plan (CAAMP) for Hutton Le Hole. Having read and interpreted some of these official documents for past academic research I was both excited and nervous to be able to produce something that would inform and offer professional guidance whilst finally gaining experience in the career path I wanted to follow.

The first week revolved around researching the history of the village and going out to see the area in person to understand the full scope of the work. The initial research phase felt instinctual, reminiscent of my previous studies and was a comfortable start to my internship. For the initial walk in Hutton Le Hole I met up with the team to get my bearings and discuss the vision and style of the Conservation Area which helped settle my nerves as we all had similar thoughts as we walked around. The starting week was informal and friendly which helped me to quickly settle in and feel like part of the Building Conservation team.

The following few weeks I began to work on my own with supervision meetings with Chris (in the distance) appraising the beckside fencing, a feature of Hutton le Hole.Maria periodically who really helped to encourage me and regularly offered some much needed advice. Through my second week I felt my work had been making slow progress into the Conservation Area Appraisal. But I then started to create my own schedules and push myself to reach bigger targets each day. My first site visit alone felt like a big and unorganised mess, I found the hours of the day had passed but I had hardly made any progress giving me cause for concern about my deadline. However, as with everything new, this quickly changed once I had a routine and the workload soon felt manageable and was an interesting and fun job to produce and complete.

Come the sixth week I had completed a draft of the CAAMP and got the opportunity to expand my experiences with using a Geographical Information System (GIS). This is something I had only heard of briefly through my studies and through applying for jobs. I had zero experience and I believe this was just as useful to practice as the Conservation Area Appraisal process. Using the Authority’s Earthlight system, under the supervision of Nick Mason the Archaeology Officer, I was tasked with plotting and producing information for the non-designated local list for the Hutton-Le-Hole parish. This, again, was a fun task to take part in and I enjoyed the opportunity to gain the additional knowledge. I knew the Conservation Area very well at this point but now I had to expand this to the whole parish, being able to explore and research the wider setting was now easier having gained the experience of recording the data for the Conservation Area already.

Hutton Le Hole by Chris J. Parker.

By my final week I had completed the Conservation Area Appraisal documents and the non-designated local list. So I got the chance to review and discuss planning applications with Maria. This gave me an insight into how the Building Conservation Team works on their more regular tasks, giving me more opportunities than planned within the time of my internship.

My internship was a fully positive experience and offered more than I expected in the time frame. I am very grateful to have been given the opportunity by Maria and Claire and I feel I have built strong relationships with them both within the short period of time at the North York Moors National Park Authority. I hope this can become a regular internship there where they can offer more experiences and, more importantly, encourage others to get involved in heritage.

Band of Six

Our Ryevitalise Landscape Partnership Scheme has been active now for over 16 months; it’s had quite a time so far. We thought it would be courteous to introduce the very adaptable delivery team.

Upper reaches of the Rye catchment. Copyright NYMNPA.

“I’m Alex, the Programme Manager for Ryevitalise. My main role is to work closely with all of our wonderful partners and the National Lottery Heritage Fund to deliver our Ryevitalise vision to ‘conserve, enhance and restore the natural and cultural heritage of the area, enabling people to reconnect with the history, wildlife and landscapes of the River Rye and its tributaries’.

I’ve always had a passion for nature. Growing up locally I have great childhood memories of taking part in lots of activities with the North York Moors National Park. In my early teens my family moved to the Falkland Islands where I was fortunate to volunteer for Falklands Conservation, spending days on end undertaking penguin chick census checks … it was amazing! My family then moved to Ascension Island where I carried out bird, turtle and endemic plant counts, and these experiences led me to pursue a career in conservation.

Alex Cripps, Ryevitalise Programme Manager. Copyright NYMNPA.I studied Environmental Science at the University of East Anglia, including a year in Canada – my dissertation focused on the impacts of habitat fragmentation on ungulates (moose, elk and deer) near Banff National Park. I then spent two years travelling and working in New Zealand before I decided I’d better get a ‘real’ job.

I was delighted to be offered a job in 2013 working for the North York Moors National Park as their Conservation Graduate Trainee. Since then I have developed a huge passion for rivers; I became the Esk and Coastal Streams Catchment Partnership Officer in 2014 before taking on the role of Ryevitalise Catchment Restoration Officer in 2017, part of a small team to develop Ryevitalise. In 2018 the final Ryevitalise application was submitted and now here we are, delivering this ambitious landscape partnership scheme and it’s great to be leading the team as Programme Manager.

I love sharing my enthusiasm for rivers and the fascinating wildlife that our freshwater habitats and surrounding areas support. For those of you who know me you will know that I absolutely love aquatic invertebrates – one of my favourite moments in the Rye catchment was watching mayflies dancing above the River Rye near Helmsley, there’s nearly always a dipper bobbing about here too.

Ryevitalise will be raising the profile of rivers, looking at how valuable these ecosystems are and how important they are to local communities. We will be working alongside local communities, including land managers and young people, reconnecting people to their local river systems and exploring how simple every day actions to help care for our rivers can collectively make a huge, positive difference. So it’s great to be underway, delivering a wide variety of projects, and I look forward to meeting some of you soon!”

Mayflies dancing above the River Rye near Helmsley. Copyright Alex Cripps, NYMNPA.

“Hi everyone. My name’s Paul Thompson and I’m the Programme Officer for Ryevitalise currently overseeing our ancient woodland restoration work, access improvements, and community arts project. I’ve also been supporting land managers in Bilsdale carrying Paul Thompson, Ryevitalise Programme Officer. Copyright NYMNPA.out habitat improvement works. I’ve been really inspired by our community who care passionately about our local heritage and rural landscape. Finding solutions to key conservation challenges that benefit people, the economy and the environment is incredibly rewarding, and demonstrates the power of National Lottery Heritage Fund’s landscape partnerships.”

View of Hawnby Hill. Copyright Paul Thompson, NYMNPA.

“Hello! I’m Amy, Ryevitalise Education & Engagement Officer; my job is exactly what it says really. Anything from working with schools, volunteers, local communities, running events and bit of historical work thrown in for good measure!

I started conservation life as a seasonal ranger for the National Trust on the lovely South East Cornish coast. Then moving closer to home to work for the Tees Valley Wildlife Trust as part of the River Tees Rediscovered project. All my roles have involved people (and rivers) in some way! Whether it’s bossing… I mean working with… volunteers; mammal surveying, running community events or working with local people of all ages. I love seeing folks reaction to the first path they have built, catching their first tad pole or that first cup of tea after a gruelling task. It’s amazing how inclusive conservation can be; wildlife doesn’t care who you are or what you can do.

Having spent many of my days as a teenager walking the Cleveland Way and hiking up Hasty Bank, it’s great to actually work here and show off what a lovely place the Ryevitalise area is!”

Cleveland Hills from Urra Dyke at top of Rye Catchment. Copyright Simon Bassindale.

“Hi! I’m James and I’m the Catchment Restoration Officer. Essentially my job involves working to improve the water quality of the River Rye by engaging with land owners, whether by creating conservation agreements which typically address point source James Caldwell, Ryevitalise Catchment Restoration Officerpollution issues, promoting opportunities to increase habitat connectivity, controlling invasive species, or helping to create a more natural river by removing obstacles to fish migration.

I had a rural upbringing and have always had a passion for the environment which is reflected in my career choice, starting as an assistant ranger for a trust in Peterborough, moving to a countryside ranger position with a borough council in Surrey and most recently settling at the North York Moors National Park Authority. 

I enjoy exploring, whether walking, running or cycling, and am delighted to have such variety on the doorstep that also forms my wider “office” and supplies great photo worthy content.”

Byland Abbey. Copyright NYMNPA.

“Hi everybody! I’m Sam Lewsey, the Field Officer for the Ryevitalise project and my main areas of responsibility are the citizen science programme, and the delivery of practical works with our wonderful volunteers.

Sam Lewsey, Ryevitalise Field OfficerI came to the North York Moors from the National Trust, where I worked as a Ranger for the last few years, and before that I worked for Cambridge University. Both my parents had a huge love of the great outdoors and natural history, and this was something I picked up from an early age. I am passionate about wildlife and love working with volunteers setting up programmes of surveying – developing my own ID skills and helping others develop theirs. Hay meadows and their associated pollinators hold a particular fascination for me. When not crawling about looking at wildflowers and fungi you’ll find me out on a run – the longer and hillier the better!

If you’re keen to get involved in volunteering with us please give me a shout and I can talk you through the opportunities that are available within this fantastic scheme.”

Riparian woodland in autumn, near Hawnby - copyright Paul Harris, NYMNPA

“Hi everyone – my name’s Ann Pease and I am the Administration Assistant for Ryevitalise, overseeing all of the background paperwork that keeps the project ticking Anne Pease, Ryevitalise Administration Assistantalong! One of my many roles is liaising between the team and the National Lottery, helping to collate and provide the evidence needed to receive our funding. 

I’ve volunteered for many years across the conservation sector – and am over the moon to be able to work on a project having such a positive effect on our areas landscape and wildlife. 

Being a local girl I am deeply connected to this landscape – I’ve spent much of my life up on the North York Moors and it’s great to see this project champion what makes the area so special. 

If I’m not working you’ll probably find me out walking somewhere – I am a big fan of National Trails and long distance walks…I am also a big fan of butterflies, moths and birds of prey and never miss a chance to have a bit of a geek out!

At the moment I am on maternity leave having had a baby boy in July (mid lockdown!), so am watching from afar – but am very much looking forward to being back in February to see how the project is getting on…”Ryevitalise logo banner

Sweetening the land

Ellie Leary – Monuments for the Future Project Officer

Not all of the archaeology within the North York Moors is as ancient and enigmatic as the standing stones or rock art (see previous posts). Once a ubiquitous presence within the landscape, you can still stumble across the remains of a more industrial feature – lime kilns. These structures were part of an industry that has shaped and changed the landscape of the area from the extraction of the limestone from quarries to its end use as a building material and soil improver.

Over 400 lime kiln sites are recorded within the National Park’s Historic Environment Record, with the evidence coming mainly from historic maps, but also earthworks and standing remains. Only three of these kilns have the benefit of protected status as Scheduled Monuments, and in all cases they are included as part of a wider monument rather than in their own right. Another three have protected status as Grade II Listed Buildings.

Grade II Listed Building (1149198) - lime kiln, Hawnby (HER 5946). Copyright NYMNPA.

The use of lime has a long history in Britain dating back to at least the Roman period and over time it has had a wide range of practical uses from forming the base of plasters, mortar and concrete; as lime-wash for waterproofing walls and lightening interiors; in the bleaching of paper and preparing hides for tanning; as a disinfectant; and as a soil improver for agriculture.

During the Roman period it was used particularly for lime-mortar, plaster and lime wash; while during the mediaeval period the need for quantities of lime hugely increased with the construction of large stone-built buildings and bridges. From the 17th century onwards however the main use of lime has been in agriculture, with it being added to soil to improve acidic soils or as a top dressing to pasture to “sweeten” the land.

In most cases in order to turn raw limestone into a useable product it has to be fired in a kiln, creating a process called calcining where calcium carbonate is converted into calcium oxide. This process was both labour and fuel intensive and the trade was known as lime burning – those working at the kilns, were lime burners.

Most of the kilns known of within the North York Moors date to the 18th and 19th centuries, although earlier examples do exist. Excavations at Ayton Castle, for example, revealed a lime kiln dated to the 14th century, which may have produced lime mortar and cement for the construction of the castle’s tower house, the ruins of which still stand.  (This is one of the three kiln sites included within a wider Scheduled Monument – see above).

The earliest kilns were simple clamp kilns which consisted of a circular or rectangular hollow within which the limestone and fuel were layered, covered with clay or turf, and left to burn for a few days. Often clamp kilns leave little obvious trace, however the remaining protected kiln sites in this area (as mentioned above) include two clamp kilns built into the bank of a scheduled prehistoric cross dyke and another cut into the edge of a scheduled Bronze Age barrow – the actual kilns are all thought to be 18th or 19th century in date. Their remains can be seen as horse shoe shaped mounds of earth and stone rubble.

As the demand for lime increased kilns became more substantial in size although the transformation process remained the same. Kilns were generally circular or square stone structures, about 3m in height, with a bowl lined with sandstone or firebricks and at least one draw hole located at the bottom of the kiln. As the contents burnt through the lime was extracted through the draw holes at the bottom. Additional layers of stone and fuel could be added to the top if necessary, otherwise one-off firings were carried out as needed. A good example of this kind of kiln can be found at Old Byland where the remains of four lime kilns stand next to a road (see image below). They are located on the edge of a quarry to the south west of the village and some parts survive to 5m in height, with two of the kilns having the roof and flue surviving.

Old Byland roadside lime kilns (HER 2680). Copyright NYMNPA.

The end product removed from a kiln was called ‘lump lime’, ‘burnt lime’ or ‘quicklime’ and in order to convert this for use it has to be ‘slaked’ – a process involving adding water to cause a reaction which produces heat and steam. By then adding enough water, putty is produced, which, mixed with sand, produces a mortar. Over time this reverts back to calcium carbonate and hardens.  When used in agriculture the ‘lump lime’ was left in heaps, covered in earth and left to slake, eventually creating a powder that could be ploughed into the soil. Other methods were used too, including leaving the lime uncovered and occasionally turning to produce the same result.  ‘Lump lime’ is a volatile material and there were inherent dangers if it started to ‘slake’, producing heat, before it arrived at the final destination.  By the late 19th century, hydration plants were introduced that could grind the lime, sprinkle it with water, dry it and then bag it for transporting.

The location of kilns largely depends on the final use for the ‘quicklime’, so that if it were needed for building construction the kilns would most likely be located close to the building site. They could then either be dismantled and moved or left to decay once they were no longer needed.

Field kilns were sometimes built by farmers and land owning estates from the 17th century. Smaller kilns would have been built by farmers for occasional use to improve their land but estates often built larger kilns to serve the whole estate and wider area, providing a profitable source of income.

Another common location for kilns was close to or within limestone quarries. Many of these quarries are still obvious on the ground now as large excavated pits; historic mapping helps to identify the full extent of the quarries and the location of kilns. The 1893 Ordnance Survey map (below) shows Sour Ley Quarry near Helmsley with up to 20 lime kilns within the quarry.

Extract from 1:2,500 Ordnance Survey Map 1893

Easy access to transportation was also another consideration for the location – for fuel to be brought in and for the final product to taken away for sale.  Colonel Sir Joshua Crompton, 19th century owner of the Kepwick Estate on the western edge of the North York Moors, built a railway line in the early 1820s which carried limestone from a quarry on Kepwick Moor down to the lime kilns and stone yard to the west. Fuel for the kilns could be easily brought in and the final product taken away on the Thirsk to Yarm turnpike road (now the A19). With a very steep incline up to the quarry the railway used gravity; as the full wagons were sent down slope they pulled the empty ones up towards the quarry, whilst horses pulled the wagons along the flat plain to the west. The quarry and the start of the now dismantled railway line lie with the National Park boundary and the lime kilns themselves are a short distance outside the boundary and are protected as a Scheduled Monument.

Lime kiln north of Sinnington (HER 4981). Copyright NYMNPA.

As the demand for quicklime grew the process became industrialised, with new kilns designed with efficiency in mind as well as a higher quality lime product. As a result most of these smaller local kilns were abandoned by the 20th century, with some being dismantled and others left to decay, remaining in the landscape as a reminder of this chapter of industry.

To keep up to date with the latest National Park response to Covid-19 – see here.

Reconnecting people to the near and far past

Paul Thompson – Ryevitalise Programme Officer

Ryevitalise is reaching out with its ‘Rye Reflections – inspired by the river’ project. We’re currently putting a call out for people to send in their memories of wildlife encounters, past activities and changes in land management practices so we can record these experiences before these precious memories are lost.  We want to document change that has happened within the living memory of our communities, providing a framework that shaped how we connect with our local landscape today and how our children will connect with this landscape in the future.

We will share these memories with local school students, encouraging them to compare these experiences with their own, highlighting the differences and similarities and inspiring them to protect our catchment habitats in the longer term.

Old photographic image of Rievaulx.

I’m really excited about Rye Reflections, and what we might find out about the landscape we think we know so well.  I remember seeing hedgehogs regularly in my garden, and my car number plate used to get covered in dead flies in the 90’s, but these are no longer common sights in 2020.  I can’t wait to hear what memories our local community have about growing up and living around the catchment of the river Rye.  I hope to share these stories and help people reconnect with nature and the river.

If you have any wildlife memories, old photographs, journals or other records that might help us inspire the next generation of landscape guardians – please get in touch with me by email or post (North York Moors NPA, The Old Vicarage, Bondgate, Helmsley, York, YO62 5BP).

And that’s not all…we’re already underway with Rediscovering the Rye project …

Amy Carrick – Ryevitalise Education & Engagement Officer

Humans have lived with, and adapted the Rye from the earliest times. The story of how and why humans adapted their environments can be traced through the ages; from low-impact exploitation in Bilsdale during the Mesolithic era, to the beginnings of dramatic alterations and clearances for cultivation purposes in the Neolithic era. Current land managers have inherited these changes which bring about the opportunity to learn about these old practices, especially the use of the flowing waters of the Rye for farming, metal extraction and working. There is documentary evidence of the manipulation of the Rye by the monks of Rievaulx Abbey, including a long-established ‘canals’ theory. Land in Bilsdale belonged to the Abbey as an important grange site with a prototype blast furnace at Laskill and was the location of the quarries for which much of abbey’s construction relied. Dissolution destruction of this technically advanced furnace (c. 1530s) is suggested by metallurgical expert Gerry McDonnell to have delayed the Industrial Revolution by 250 years.

On the earth science side, there is a complicated story of how the Rye runs along various complex geologies, impacting on the unusual behaviour of the water; disappearing down sinkholes, bubbling up unexpectedly at springs, flash floods and how communities have managed to adapt to the unexpected ways of the river.

But where to start? We needed to design a project to enhance our understanding of the Ryevitalise landscape through river science and field investigation but also provides a unique and engaging way for our volunteers to engage with archaeology.  Which lead us to….LiDAR! LiDAR (Light Detecting and Ranging) is a relatively new technique that records ‘lumps and bumps’ on the ground using a laser mounted aeroplane. LiDAR data, originally commissioned by the Environment Agency for non-archaeological purposes, is available in most areas of the Ryevitalise catchment. This data can be processed into LiDAR maps that show the ground surface in amazing detail beneath the trees and vegetation, including previously unrecorded archaeological features.

Example of a 1km LiDAR data grid square.

So with our 30 eager volunteers and academics from Durham and York Universities Ryevitalise hase set about this exciting project, the initial stages of which can usefully be done at home! Volunteers will be given their own 1km square of LiDAR, within the Ryevitalise area, to analyse and annotate for any possible archaeological sites. These will then be validated by our project consultant, Paul Frodsham (ORACLE Heritage Services), leading to a list of intriguing sites to explore further through Ryevitalise …

Although this particular project now has a full quota of volunteers, if you might be interested in other Ryevitalise volunteer opportunities, please see here.

Ryevitalise Landscape Partnership Scheme logos

A to Z: a variety of Us and Vs

U, V

Underwood

Underwood is a term for trees within historically managed woodland (Silva minuta in the Domesday Book) – the ones grown and managed for common usage such as wattle for buildings, stakes for fencing, and firewood and charcoal for fuel i.e. not for building timber. A managed woodland often included underwood as well as timber trees left to grow big and straight. Underwood is made up of the trees that were coppiced and pollarded over and over again – from early history on to the post medieval period.

The underwood was managed frequently so trees stayed smallish, and their crop of wood was productively harvested much more often than from the timber trees and so the underwood could be worth more than the timber. What is left of the historic underwood can sometimes still be seen within semi natural ancient woodland – look for idiosyncratic-shaped overgrown veteran trees. Because the trees were managed and encouraged to rejuvenate they have lived a lot longer than single timber trees which were felled. They are as much cultural heritage as natural heritage. 

Veteran tree - grown up underwood - in the upper Rye catchment. Copyright NYMNPA.

Whereas oak and beech might be more likely to have been left to become timber trees, the quicker growing underwood species were often more of a mix such as crab apple, holly, service, ash, sallow, hazel, maple, thorn, wych elm, birch. Careful rotation would be needed to give the different species the best chance to flourish and to ensure there was always wood available to the people who had the rights to collect it. The species mix were what came naturally in different parts of the country and what thrived in local conditions.

From the 18th century onwards, as demand altered, the products from underwood became less valuable and timber trees became more so, and therefore the management and species proportions of woodlands changed. During the 20th century predominantly conifer planted woodland for timber prevailed.

Urra

Urra Moor, part of the Cleveland Hills, contains the highest point on the North York Moors – 454 metres above sea level, at Round Hill. There is a lot of prehistoric archaeology in the area – cairns, lithic scatters and a flint arrow head find. Being at the highest point for miles around is always going to be useful for humans as well as significant.

There is some disagreement over where the unusual name Urra comes from. Most simply it might mean hill from the Norse haugr, or it could imply a more impressionistic idea of the darkness and gloom of such a wild barren area and be from the Old English word for dirty – horheht/horhig/horuweg. Try speaking the words without pronouncing most of the consonants.

Trig Point on top of Round Hill, Urra Moor. Copyright NYMNPA.

Obviously it’s not the time to explore Urra Moor, due to the Covid-19 situation. Please do not travel into or around the North York Moors National Park unless this is absolutely essential (essential travel does not include travel for exercise or to second homes and holiday accommodation). The National Park will be here waiting for you to enjoy when it is safe to do so.

Urtica dioica

The European stinging nettle (Urtica dioica) is found where there are high amounts of nutrients in the soil and so is usually associated with habitation and other types of development. It is often frowned upon as a ‘pernicious weed’ because it is such a successful perennial that spreads through its rhizomes and runners, out competing other plants. At least it wont be suffocating many wildflowers however as many of those don’t appreciate nutrient rich soils.

Urtica dioica has serrated edged leaves and small grouped flowers. The leaves and stem are covered in hairs the tips of which can deliver a biochemical sting into your skin if touched (Urtica comes from the latin word for burn). This active element may be one of the reasons some people think it has medical efficacy. The plant can be usefully added to compost, and it (as a young plant only) can be used as an ingredient in food and drink, the immediate danger being in the collection rather than the eventual digestion. N.B. Don’t partake of any wild plant unless you are absolutely sure you know what it is and whether it really is edible or not. 

From a biodiversity point of view the nettle is particularly useful as a living plant because it acts as a host for the eggs and then provides vital food for the caterpillar stage for a multitude of butterfly and moth species – including Comma (Polygonia c-album), Peacock (Aglais io), Red Admiral (Vanessa atalanta), Small Tortoiseshell (Aglais urticae), Angle Shades (Phlogophora meticulosa), Buff Ermine (Spilosoma luteum), Burnished Brass (Diachrysia chrysitis), Dot Moth (Melanchra persicariae), Ghost Moth (Hepialus humuli humuli), Mother of Pearl (Pleuroptya ruralis), Setaceous Hebrew Character (Xestia c-nigrum), Snout (Hypena proboscidalis), Spectacle (Abrostola tripartita), White Ermine (Spilosoma lubricipeda).

Red Admiral caterpillar on nettle plant. From Butterfly Conervation website.

Verjuice

Verjuice (Verjus) is the liquor that comes from pressing unripe fruit. The word means ‘green juice’ – ‘green’ conveying the tart un-ripeness of the fruit. The fruit used depended on what was available in the region. In and around the North York Moors that would have largely been crab apples, and maybe gooseberries. The fruit would have been pressed/crushed to abstract the liquor. The remaining mush could be fed to animals like pigs. The liquor could be used to flavour food with sourness – it is very acidic, like lemon juice before lemons were widely available, like a mild vinegar or a bad wine – and as medicine or tonic. The Crab apple tree (Malus sylvestris) is native to Britain and the trees were mostly wild in the past, although sometimes used in fencing (i.e. manipulating woody species to create enclosure hedges). In the 19th/early 20th century foraged crab apples were collected along with orchard fruit from the North York Moors to be sent off to jam factories; crab apples have a particularly high level of pectin to help the jam set.

Crab Apple Tree in Tripsdale. Copyright NYMNPA.

There are a couple of records of parts of Verjuice presses included in the North York Moors Historic Environment Record (HER 840 and HER 19525). There is also at least one ‘crab mill’ which would have been driven by a horse, conserved as a feature in village of Sutton under Whitestonecliffe on the edge of the Moors. Crab apple trees are much less common than they were, both in the wild and in the hedgerows.

Image of a Crab Mill

Vernacular

Vernacular buildings were domestic and functional. They were ordinary in their time – built out of local materials (what was to hand) using traditional techniques. The vernacular buildings in each area might look similar, but are very rarely identical. It is this local distinctiveness that makes these buildings particularly important nowadays and therefore the best examples are worthy of being listed.  From the 19th century onwards materials became more easily transported around, house building was done on a more uniform and larger scale, architectural techniques and fashions were reiterated across the country – so the term vernacular is mainly used only for pre 19th century buildings..

Vernacular buildings have been described as a component of the landscape and not just because they’re built from materials hoved out of the local geology. The buildings needed an appropriate toughness to withstand the weather.  They are patched up over time to stay useful sometimes these phases of building add to the character sometimes they might deflect. But vernacular buildings,  whether they’re listed or not, always have a connection back to the people who built them, lived in them, drank in them, kept their animals in them. 

In the North York Moors vernacular buildings that still stand are mainly from the 17th and 18th centuries. The most typical are built from sandstone and clay pantiles. Around Whitby cut ashlar blocks and quoins (corner stones) are common instead, and along the south edge of the Moors buildings are often built out of mixed rubble and quoins or sometimes gritstones/limestone. Materials were often re-used; after the Dissolution (mid 16th century) new or repaired buildings around some of the dissolved Abbeys and Priories of the North York Moors ended up a characterful mix of the vernacular and the spectacular.

Whereas it can be easy to see why stately homes, churches and castles are listed (protected for the nation), it can be more difficult to identify which of the many vernacular buildings of England should be listed too. Historic England have a series of Listing Selection Guides.

Vernacular building (not listed), after repairs - Raisdale. Copyright NYMNPA.

Previously on the North York Moors A to Z … ABCDEF, GHI, J, KL, M, N, O, PQRS, T

Interiors

Kelsey Blain – Development Management Graduate Trainee

When you find yourself in your home a bit more than you’ve been used to you might want to look up and consider your ceilings.

Our Building Conservation Team are particularly keen on the ceilings in older houses and buildings in the North York Moors that have historic interest and value that can be easily lost but could be skilfully repaired.

Ceiling and frieze of the first-floor great chamber, Helmsley Castle, Yorks (c.1582). From http://clairegapper.info/Plaster ceilings (and walls) form an important historic, architectural and aesthetic feature in many of the historic buildings within the National Park and elsewhere. They are often composed of lime or earth and can be finished to varying degrees of ornamentation depending on the status of the building or room in which they are housed. Ornate examples may be found within the high status buildings such as Helmsley Castle (currently closed), where the design and finish of the ceilings often reflects the wealth and standing of the building’s previous residents.

Interior plaster walls and ceilings in Spout House, Bilsdale. Copyright NYMNPA.More functional styles of plaster ceiling can be found within the vernacular buildings of the North York Moors, such as Spout House in Bilsdale (currently closed), where the composition and application of the plaster is indicative of the building’s traditional character.

As such, plaster ceilings and wall coverings provide a useful insight into the cultural and architectural history of a building and make an important contribution to a building’s significance. It is for this reason that the repair of plaster ceilings should always be preferred to their replacement in order to conserve the historic, evidential and aesthetic value that they possess. Furthermore, repairing traditional plasters over replacing them has a lower carbon footprint, and traditional materials better preserve the health of the building.

Here is a recent instance of repairs being carried out to a particularly fine plaster ceiling in nearby York which might not be exactly typical – but repairing all sorts of lath and plaster ceilings is possible. Our Building Conservation team can offer advice and help (by email or phone but currently not in person) if you are lucky enough to have a likely building in the North York Moors.