War Memorial #678 ~ Saddleworth EarthCache

War Memorials often feature as EarthCaches because they are easily accessible, located in the centre of communities and are often made from an impressive stone type foreign to the area. This War Memorial is absolutely none of those things - it sits high on the moor above the valleys below, in a remote and exposed location. It is also constructed of local stone similar to that found in the rocks nearby. But it is still very interesting for different reasons.

So why was it positioned up here so high above the valley? This cenotaph was erected in 1923 to honour the 259 people from all the villages of Saddleworth who died during the first world war. Therefore, it was positioned here specifically to be visible from all those villages.

This EarthCache looks at the type of stone used to construct the memorial and after analysing a number of key points, you will decide whether you agree with the choice made nearly 100 years ago to use this type of stone up here in such a bleak location. All the information in this listing is based on a very interesting Historic England/War Memorial Trust document specifically about the stones found in war memorials and the problems they face.

This is an observational EarthCache - this means to answer the questions you only need to observe what you see here and use the information included in the listing to form your answers. No other research or previous knowledge is required so please do give this EarthCache a try!

Back in the early 1920s a group of people from the Saddleworth villages raised enough money within the local community to build an impressive war memorial and lets assume the location had been already agreed to be up here near the Pots and Pans rock formation. This group of people had to make a choice as to which stone they purchased to construct the war memorial. We are going to look at the main types of stone often used for such memorials at the time.

Sedimentary Rock Options

Limestone - A sedimentary rock largely made of calcium carbonate (often in the form of crushed shells or round grains called oolites). It is found mainly in the Midlands and south of England and is generally soft enough to be worked by hand. Minerals such as clay and iron can change the appearance and characteristics of the stone considerably. Its durability will also be affected by the way in which it is used (especially the orientation of the natural bedding plane) and the degree of weathering to which it is exposed. The colour and texture of limestone varies from the even, fine texture of pale grey Portland (Dorset), through to the rich, warm, yellow, open texture of Ham Hill (Somerset). It has been used for almost all components of memorials, including steps, ashlar blocks and columns, as well as for decorative and carved elements.

Sandstone/Gritstone - A sedimentary rock found most commonly in the north and west of England. It varies considerably in texture, durability and colour – from the deep red of St Bees (Cumbria), to the pale cream of Stancliffe (Derbyshire). These differences in appearance and behaviour derive from the way in which different grains (mainly quartz but also clay, feldspar, mica and glauconite) are bound together by the natural cement of the stone (mostly quartz but also calcite and iron compounds). The mineral content and the type of cement give rise to the geological terminology such as argillaceous sandstone (containing significant amounts of clay) or calcareous sandstone (quartz bound together by calcite). Like limestone, it is a versatile material which can be used for almost any purpose on a memorial. Although many sandstones appear durable, they are susceptible to weathering and deterioration - some faster than others.

Igneous Rock Options

Granite - The most common form of igneous rock found in Britain. It is coarse-grained and mainly formed of quartz, feldspar and mica crystals. These provide the typical flecked appearance and colouring that varies from pink to grey. It is mainly sourced in Devon, Cornwall and Scotland. Granite is dense and durable but because it is difficult to cut using hand tools it is rarely used for fine carving. It can be polished or left with a rough tooled surface finish. In memorials it tends to be used for substantial elements such as columns, plinths and crosses.

Methamorphic Rock Options 

Slate - A metamorphic rock naturally found in several regions of England. At one time the Midlands contained many slate quarries but these are now redundant, though other sources in Cumbria and Cornwall are still active. Slate is formed from the recrystallization of fine-grained sedimentary or igneous rocks under extreme pressure or temperature. It is extremely durable and fine in texture but its layered structure makes it liable to de-lamination (flaking). It is often used for inscription panels.

Marble - A metamorphic rock that has a close-formed matrix composed mainly of calcium carbonate, with mineral inclusions that impart colour. There are no true marbles from England, only limestone that can be polished, such as that from Purbeck (Dorset). The marble found on memorials is therefore imported and consequently expensive. It is usually finished to a fine polish and was often used for inscription panels or sculpture. Perhaps the most common marble encountered is white Carrara from Italy; its purity of colour and fine-grained texture made it ideally suited for detailed carving. External marble is susceptible to weathering, particularly through sugaring of the surface. 

Whichever stone the people of Saddleworth selected, it would have had certain advantages and disadvantages and this final section looks at the main risks to the stone used on war memorials. The location of this memorial will help determine which of the potential problems are likely to apply here.

The stone components of war memorials are subject to a variety of decay mechanisms that can be generally categorised as chemical, physical and biological. The presence and behaviour of moisture is a common theme and plays a significant part in any deterioration. Because stone is a natural material it is bound to deteriorate to some extent over time but decay can also be due to previous attempts to repair or preserve the memorial.

Chemical - Some atmospheric gases, such as sulphur dioxide, nitrogen oxides and ozone can cause decay of stone surfaces. The effects are associated with the formation of gypsum (calcium sulphate), a mineral that is more water-soluble than the carbonate minerals from which it is formed. This is typically found as a black crust in protected areas of limestone memorials. Marbles (and some limestones) are particularly sensitive to chemical attack from acids formed from the combination of pollutant gases and water. This can lead to erosion of detail (especially lettering) and the loosening or ‘sugaring’ of grains. Mineral changes near the surface of sandstone can cause a brittle and less permeable crust to be formed. This eventually exfoliates and is often referred to as ‘contour scaling’. Deposits on sandstone, unlike those on limestone, are not generally durable, can deteriorate (particularly in damp polluted environments) through the breakdown of silicate minerals within the stone; this results in crumbling of the surface. Rainfall can be slightly acidic as a result of both the dissolution of carbon dioxide and pollution. This can lead to the erosion of limestone and marble as well as encouraging mineralogical changes in other stones. 

Physical - Sedimentary rocks, such as limestone and sandstone, are formed by deposition of particles, which build up in layers termed ‘beds’. In any construction, stone should be placed so that its natural bedding plane is perpendicular to applied forces or weathering. If this is not the case, weathering takes advantage of the natural weaknesses between the beds and can lead to delamination of the stone. Inscription panels, particularly because of the height required, may be ‘edge bedded’ with their bedding planes parallel with the face. This makes them susceptible to delamination leading to loss of inscriptions and surface details. Beds within sedimentary rocks can also contain varying amounts of clay. As clay expands when wet and contracts as it dries, repeated wetting /drying cycles can cause clay-rich beds to decay preferentially. This can be manifested either through different degrees of erosion or (for sandstones particularly) delamination of the surface. Slate is extremely durable and may remain sound even in the most inhospitable situations, but it is still susceptible to delamination. 

With war memorials, another physical weathering problem is disruption through soluble salts. Salts can be present as a result of: 

• Ground water which contains dissolved salts derived mostly from the natural degradation of plant materials ? 
• Rainfall run-off or splash–back contaminated with salts, especially from roads and pavements treated with de-icing grit 
• Materials used in the construction or repair of a memorial, especially cement 
• Sea salt either from contaminated sand used in the construction or, for memorials close to the sea, blown by the wind 

The stone of a memorial is normally buried in or has contact with the ground and, because stone is generally porous, it will act as a wick for both the ground water and any run-off or splashing of contaminated rainwater. As this evaporates salts will appear as crystals, often white in colour. This is generally referred to as efflorescence and should not cause major damage; it can be brushed off with a natural bristle brush. When salts crystallise within the sub-surface pore structure of the stone (known as cryptoflorescence), internal stresses are created which lead to the weakening and loss of stone. Repeated wetting and drying cycles exacerbate this process by causing salts to go into and out of solution. 

Freeze/thaw activity is also a physical weathering problem. The way that water runs off may not have been a principal consideration when the memorial was designed. However, if there are flat areas (for example paving or steps) or open joints and surface voids where water is trapped, the surface may remain saturated. If water within the pores of the stone is subject to freezing, it can create a bursting pressure that causes decay. A freeze/thaw cycle can be repeated many times each winter, leading to crumbling of the surface and the gradual disappearance of details such as inscriptions. Frost damage on stone memorials can be extensive and destructive, particularly if the damaged stone is not repaired before the next winter.

Biological weathering is the final category.

• Trees - Well-maintained war memorials tend not to be liable to damage from this source. However, trees may be an intentional or unintentional part of the surroundings of a memorial and so they can become invasive. For example, memorials too close to trees can suffer damage from roots or staining from deposits such as sap. 
• Shrubs and climbing plants - These can engulf a memorial, prevent the evaporation of moisture and attach themselves to vulnerable surfaces. Woody species, such as Buddleia cause physical damage by establishing root systems within joints which then push elements of monuments apart. Creeping plants, such as ivy or Virginia creeper are tenacious and can cause physical damage as well as trapping moisture and encouraging staining on the surfaces. There are many non-woody herbaceous plants that cause no problems, but any plant that causes disruption to pointing between stone elements can cause moisture to get into the memorial with potential adverse consequences.
• Lower plants - The discolouration and patina caused by microbiological growths (such as bacteria, moulds, algae and lichens) often add to the mellow and historic appearance of war memorials. Although this may be generally desirable, excessive colonisation can obscure inscriptions. Some growths secrete acidic deposits or hold moisture, which in the long term may lead to slight deterioration of the stone surface.

Human interventions are the final category we need to consider as well as the natural threats to the stone of a war memorial. Despite the best of intentions, some previous repairs of stone memorials may have led to further deterioration. This is why it is so important that the correct methods and materials are used. The most common ways in which previous repairs can cause problems are:

• Cleaning - Stone is vulnerable to inappropriate cleaning processes that lead to the pores of the surface being exposed; this allows pollutants to collect and microbiological growths to become established. The cleaning process might have been too aggressive (for example sand blasting), inappropriate for the type of stone (for example chemical cleaning of limestone with acidic-based cleaners) or too frequent (for example regular maintenance using a pressure washer).
• Pointing - It is likely that most stone war memorials will have been repointed at some stage. This is primarily to prevent moisture ingress and plant growth but it also improves the appearance. Cement mortars were often used in the past, but these tend to be hard and impervious. They will tend to crack and encourage moisture movement through the adjacent stone rather than through the pointing; this can lead to accelerated decay of the stone.
• Surface treatment - Products that claim to protect and preserve stone have been around for a long time. Many of these were based on silicones, more recently replaced by siloxanes. All of them will claim ‘moisture permeability’ but this usually means that they are permeable to water vapour and not liquid water. If used in the past they will have changed the moisture transfer characteristics of the stone, which can lead to lamination of the surface. 

We have a local example of poor maintenance as just down the road in Uppermill a gritstone memorial similar to this one was damaged a couple of years ago (pictured above). The intention of the stone mason was to roughly paint over the lettering on the memorial and then rub off the surface paint with a carborundum stone. This is a technique used on granite, and the stone mason was unaware that he would be unable to clean the paint off gritstone without damaging the stone (a local councilor had to stop him when he spotted it!). With difficulty the paint was later removed and the lettering has now been permanently painted in to protect the damaged stone. So you can see how even experienced stone masons can fail to understand the difference between stones and make costly mistakes.

Please visit the listed coordinates at the war memorial. The questions all relate directly to the information provided in the listing so you should be able to answer everything from GZ with no extra reading required. Please ensure you send in the answers at the time or soon after you log your find, as logs may be deleted if no attempt at the answers are made.  

1) Take a close look at the stone used to construct the monument and from the list of choices given above, which stone type did the people of Saddleworth select?

2) Please firstly study the war memorial. From the 'Decay, Deterioration and Damage' section we see the problems war memorials can face after being exposed to the environment for a long period of time. Which of the potential problems can you identify on this war memorial?

3) You have identified a number of weaknesses in Q1 but looking at the stone from a positive perspective, what parts of the war memorial have aged well?

4) When this EarthCache was published, the memorial here was almost 100 years old. How do you think it will stand up to the next 100 years?

5) At the start of the EarthCache we looked at some other rocks types often used for war memorials. Some have a more decorative look, some have more impressive colours and some are harder and more durable. Imagine you had been in charge of choosing the stone used for the memorial in this exposed location, would you have used any different types of stone? This could be either for the entire memorial or just for certain bits (let's assume you have whatever money you need but need to spend it wisely). Explain what you would change and why (or why you wouldn't change anything if that is the case).

Please note. Non spoiler photos are always welcomed. At the time of publication if you are in an area where there is no signal and you write your answers into the message center it will not queue the message to be sent later as it does with logs - instead it will be deleted immediately by the app if it fails to send. Please be aware of this as I need to receive your answers. If you don't get a pop up saying 'message sent' then it hasn't!

Thank you for visiting the Saddleworth War Memorial EarthCache

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The series is dedicated to those who fought for their country. "We will remember them!”

If anyone would like to place a War Memorial Cache of your own then please do so. We would ask if you do so please contact Just-us-Two through their profile page or justustwo1013@gmail.com
so they can keep track of the numbers

Please note, physical caches are not allowed to be placed on the actual memorial or within the boundary of such memorials. Please treat war memorials with the appropriate respect when finding or hiding geocaches.

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