Lastingham Gravestones – an environmental story

 

 

Lastingham gravestones have many stories to tell.  Dating back to 1701, their inscriptions certainly tell us a lot about the residents of Lastingham and nearby villages.  They also tell us a story of changing architectural fashions – from the oldest, low 18th century stones with their typical, ornately-carved tops, through the splendid art deco examples of the 1930’s and 1940’s, to today's modern, simple granite slabs.  Over time, the types of stones used have changed; so have lettering styles, and the information the stones give.  All of these stories are to be found in several, well-organised ‘rooms’ of the churchyard (such as those created in 1800+. 1900+ and 1930+) and in the gravestones themselves, which are mostly orientated north/south, with the inscriptions facing east.

But there is another, quite different story written on the gravestones – the story of environmental change as revealed through ‘weathering’ – the breakdown of the stones over time.  This story is a part of the environmental history of Britain over the last three hundred or so years.

Put simply, all the rocks used in gravestones are unstable in the atmosphere because they were formed in totally different environments.  The local sandstones, for instance, were formed in fairly shallow seas; the granite was created deep in the bowels of the earth; and the marble was forged from limestone under conditions of high temperature and pressure.  So. When they are exposed to the atmosphere, they begin to break up.

How they break up depends mainly on four things:

 

·         The type of rock and its intrinsic properties (e.g., chemical composition and crystal structure)

·         The design, geometry and craftsmanship of the gravestone.

·         The position of the stone, and the length of time it has been exposed.

·         The environment (including climate, changing tree shelter and ground conditions).

 

Most important, because each stone has a date on it that indicates when it was put in place, it should be possible for similar gravestones to be used to measure the rate of stone decay within the graveyard.  For example, take the marble stones that have lead lettering embedded in them (these gravestones are mostly of Carrera marble that was introduced in the early – mid 1800s).  The marble is dissolved in ‘acid’ rain, but the lead lettering is unaltered – thus, if we measure the distance from the original surface of the letters to the marble surface (with a micrometer) we have a measure of the amount of weathering since the gravestone was put in position.  Then, if we measure the amount of weathering from many marble stones with the same orientation, but of different ages, we can work out haw much change has occurred over time.  This method has it’s problems – for example, the marble must be the same in all the stones measured, the shelter provided by trees will certainly have changes over time, and the orientation needs to have been unaltered.  But we have used it throughout the British Isles and have been able to show how the rates of weathering vary across the country, and over time.  Not surprisingly, the fastest rates of weathering are to be found where atmospheric pollution was greatest.  Where?  The lower Swansea valley, the 19th century centre of non-ferrous metal smelting!  By contrast, my impression of Lastingham is that, as you might guess, it has not had a history of severe ‘acid’ rain pollution.  The marble tombstones, while they do show some signs of weathering, are relatively fresh.  (Another piece of evidence that Lastingham is relatively unpolluted today – as if you didn’t know! – is to be found in the lichens growing on gravestones.  In general, lichens do not flourish in a polluted atmosphere – in Lastingham they are rampant!).

There is a lot of other evidence of weathering of gravestones at Lastingham, but it needs to be carefully interpreted.  Many stones are local Jurassic sandstone, but they are not all the same; some weather more easily than others (and some of the oldest are almost unaltered).  Some of the sandstones break up by small sheets peeling off – this is a result of weathering working along the original ‘bedding planes’ in the stone.  Others show considerable, sometimes powdery, decay towards the bottom to the middle of the stone, on the inscribed side.  This is quite common, and its cause is not certain.  It may result from ‘rising damp’, or from water movement from one side of the stone (where the rain hits it) to the other (where it evaporates).  Elsewhere, you can see where rainfall has flowed down the stone surface and weathered away some of the lettering.  Interestingly, the relationship between the extent of these weathering features and the age of the gravestone is not always as you would expect. For example, the most weathered stones are not always the oldest.  Almost certainly this is because the original characteristics of the sandstones themselves are variable.  So, for instance, some quite new stones may be quite weathered because the stone is of ‘poor quality’.

Next time you’re in the graveyard, take a closer look at the gravestones.  They speak to us from the past.  They speak to us about the past, and the changes that have occurred both in this beautiful spot, and in our culture and environment over the past three hundred years.

 

 

Ron Cooke     York, 2005