All Saints Church in Darfield - Part 3

A general view of the east elevation

Standing back in the very large churchyard of All Saints church, in Darfield, the east elevation appears as a vast expanse of Mexborough Rock, laid out in large and often wide ashlar blocks. This massive, cross-bedded medium grained sandstone is generally light brown in colour, with a variable content of oxides and hydroxides of iron, which can add a general orange colour in places, with concentrations in bands and Liesegang rings. 

A general view

Also, like the variation of the Mexborough Rock known locally as “Rotherham Red” sandstone, it contains varying amounts of clay ironstone pebbles, which are often found concentrated in distinct beds - sometimes containing fossils of Carboniferous plants. 

The east window of the north chapel

With various old quarries located a few hundred metres away to the east, on the other side of the River Dearne, the fabric of the church provides geologists with a good opportunity to study these various physical characteristics. 

The chancel window

Looking more closely at the individual blocks of stone, very many have been blackened by the pollution from industry and coal fires. Others are covered in soluble white salts, which have evaporated from rising groundwater and, during continual phases of wetting and drying, have broken down the stone by forces generated by their recrystallisation. 

The east window of the Lady Chapel

When investigating mediaeval churches, I am always interested to see how changes in the patterns of masonry indicate various phases of construction, as seen in the tower of All Saints church, but the ashlar masonry of the east elevation is quite uniform. 

A detail of the east window to the north chapel

As a geologist, I have developed a good eye for detecting variations in colour and texture of the stones that I encounter, but I am still learning from Pevsner, Historic England, church guides and other published sources, when it comes to the dating of the various architectural elements – all of which are generally not very methodical or comprehensive. 

A detail of the Mexborough Rock

The three windows of the east elevation are quite different, with those of the chancel and north chapel being Perpendicular Gothic in style, with their emphasis on upright elements to the tracery and use of simple cusps, but that of the Lady Chapel – in a Decorated Gothic style with headstops - seems to be disproportionately large. 

Crystallising salts and cavernous decay in the Mexborough Rock

Further examination of the plinth courses and butted joints in the masonry, between the chancel and the chapels on either side, reveals that the north chapel is an obvious new addition and that the pre-existing south chapel has been partially rebuilt.

A general view from the south-east