St. John's Church in Mexborough II

 

A detail of limestone and sandstone in a buttress

Continuing my investigation of the masonry at St. John’s church in Mexborough, a closer look at the Early English chancel reveals that, unlike the later Perpendicular Gothic elements, limestone has been used in the dressings for the door and windows, as well as for the buttresses.

 

A detail of the chancel

In the diagonal buttress, the original stone is pale yellow Permian dolomitic limestone, but it has been repaired at a later date with a Jurassic shelly, oolitic limestone, which may be from the Lincolnshire Limestone Formation at Clipsham in Rutland. The examples that I have seen are much coarser than the Ancaster stone used in many restored dolomitic limestone churches, but Clipsham stone isn’t used very often in South Yorkshire.

 

A lancet window in the chancel

Moving along to look at the lancet windows, the pale coloured limestone used for the dressings appears to be original and, although the surface has weathered slightly to reveal fine cross-bedding and ripples, its cement is quite crystalline and dense and it has therefore lasted very well.

 

A detail of a window surround

The coursed rubble walling of the chancel is built in sandstone blocks that have varying degrees of orange iron staining, which is typical of the Mexborough Rock in this area; however, several blocks are wholly or partially reddened with the same colouration as ‘Rotherham Red’ sandstone.

 

Walling stone in the chancel

The geological memoir for Barnsley describes the occurrence of this mottled variety in a road cutting near Denaby, which has probably long since disappeared. Although I have seen it many times where used as a building stone, I have yet to see a rock exposure where red/yellow mottled Mexborough Rock appears.

 

A Perpendicular Gothic style chancel window

At the west end of the chancel, a large Perpendicular Gothic style window has been inserted into the C13 coursed rubble wall, with limestone used for the dressings and sandstone for the sill and the large traceried head, which is formed from one piece of stone.

 

A detail of the parapet to the south aisle

Looking up at the east end of the south aisle, the parapet is formed with face bedded fine grained sandstone, which is not suited for use in exposed weathering details like this. In places, this silty stone has weathered to reveal the internal cross-laminations and some areas are deeply eroded.

 

A silty sandstone used for a gravestone