St. Mary's Church in Wheatley

 

The west end of St. Mary's church

The village of Armthorpe is mainly associated with Markham Main Colliery and, although mentioned in Domesday Book and I saw a couple of buildings that are marked on the 1854 Ordnance Survey map, the Church of St. Leonard and St. Mary is its only listed building. 

 

Our Lady of Sorrows and Saint Francis Roman Catholic church

 

Having had a look at is exterior and interior and collecting a few glaciofluvial pebbles from the churchyard, I then took a few photos of Our Lady of Sorrows and Saint Francis Roman Catholic church (1959), where serpentinite has been used for the door surround, before catching the No. 382 bus to Wheatley. 

 

Views of St. Mary's church

A British Listed Buildings Photo Challenge showed just a couple of buildings in the vicinity, St. Mary’s church (1885) and Strawberry Lock; however, the latter didn’t appear to be easily accessible and I therefore only visited the church, which was designed by Lord Grimthorpe. 

 

A view of the west front

It had been originally been my intention just to take a few record photos, but I was quite curious about the stones used to build the church. Although an overcast day, the walling stone appeared to have quite a noticeable green/grey colour, which I had noticed in St. Bartholomew’s church in Old Whittington the week before. 

 

A detail of walling stone and quoins

 

At St. Bartholomew’s church, the stone used was obtained from a Pennine Lower Coal Measures Formation sandstone, the Wingfield Flags, which obtains its colour from the presence of the mineral chlorite, like its northerly equivalent - the Greenmoor Rock.

 

A window in the south aisle

 

The well established railway network enabled the specification of a wide variety of building stones, as an alternative to the local dolomitic limestone from the Cadeby Formation. Ancaster freestone, with its distinctive ripple marks, has been used for the quoins, window surrounds, other dressings and for headstops to the west door. 

 

A headstop

The headstops have in part accumulated a thick black crust, formed by industrial atmospheric pollution and is associated with the formation of calcium sulphate, a soluble salt which can cause great damage when it is absorbed into the pores and then recrystallises. 

 

A headstop

Lord Grimthorpe, then only Sir Edward Beckett Denison, also designed the Church of St. James (1858) in conjunction with Sir George Gilbert Scott, which is built entirely in Ancaster limestone. The headstops here, which are also partially covered with a black crust, are very similar in style and look like they have been carved by the same sculptor, despite a difference of 27 years in age. 

 

A capping stone on a buttress

The capping stones to the buttresses on the west end are made of a cross-bedded, coarse grained and shelly limestone, which I thought is probably Ancaster weatherbed, which is typically 'blue hearted' but here has differentially weathered to reveal a cream colour. 

 

Capping stones on a buttress

 

Back in 1996, I worked for a few months at the Gregory’s Quarry in Mansfield, sawing White Mansfield  dolomitic sandstone, Chilmark calcareous sandstone, Ancaster hard white limestone and Ancaster weatherbed. The latter is very dense and, when feeling its resistance to the saw blade, I understood why this generally very durable variety of Ancaster stone has been used for weathering courses. 

 

Over the years, I have seen very many examples of differentially weathered Ancaster freestone that reveals its ‘streaky bacon’ texture, but I was very surprised to see a section of a buttress where the conversion of calcium carbonate into calcium sulphate seems to be in progress - a process that results in a significant increase in volume. 

 

Red sandstone used for the plinth course and quoins

 

The plinth course and the quoins to the lower sections of the buttresses are made with a dull red sandstone that is both massive and very coarse grained with small pebbles and medium grained plane bedded varieties. 

 

Another view of red sandstone used for the plinth course and quoins

I have encountered reddened medium grained gritstone from the Corbar Grit/Ashover Grit at Birchover and Cromford along the Derwent Valley, but I don’t recall ever seeing small pebbles in these. A Google search mentions that reddened gritstone is found at Spofforth and Follifoot in North Yorkshire, both of which were connected to the railway network when the church was built. 

 

A detail of the quoins used in a buttress

 

One section of the plinth course is badly weathered and very friable and I managed to obtain a small piece of this, which subsequently partially disintegrated. Immediately below the blackened surface, the sandstone is quite reddened, but the body of the stone is a dull mauve colour. 

 

A heavily weathered stone in the plinth course

Comparing the piece from the plinth course with a specimen of the Rotherham Red variety of the Mexborough Rock, which comprises a drill core from my house when a new boiler was installed, the colours are very similar. Examining them both with the naked eye and a hand lens, although the former is poorly cemented, they are both medium grained and the mineralogy also appears to be similar - although petrographic analysis would be needed to confirm this.

 

Comparing the sample from St. Mary's church with my Wentworth scale

  

The generally very coarse texture rules out the use of Rotherham Red sandstone, as this is fine to medium grained and in my experience doesn’t contain pebbles. Although the geological memoir mentions a quarry at Spofforth and that the Plumpton grits did produce building stone, referring to Spofforth castle, the Building Stones Database for England map explorer doesn’t show quarries at either Spofforth or Follifoot. 

 

Sandstone from St. Mary's church (top) and my house (bottom)

At some point, the deterioration of the stone to the plinth course will require it to be restored, using a red sandstone that matches the original as closely as possible. As seen in the Triton Stone Library, now in the Redmires Building at Sheffield Hallam University, the vast majority of red sandstones quarried today are from the Permian and Triassic periods, with these being much brighter in colour and obtaining a good match is therefore not easy.

 

The Triton Stone Library in the Redmires Building