The Brotherton Formation in Doncaster

 

A detail of an old quarry face in The Dell

When leading the Sheffield U3A Geology Group field trip to Anston in June 2023, I essentially shared my knowledge of visiting Anston Stones Wood many times and my professional experence of more than 25 years spent surveying very many geological sites on the Permian Cadeby Formation and innumerable historic buildings that are built from this dolomitic limestone – from Aberford in the north to Mansfield in the south, where it is classified as a dolomitic sandstone.

 

The outcrop of the Brotherton Formation in Doncaster

 

Starting with my survey of the potential RIGS (Regionally Important Geological Sites) in Doncaster back in 1997 and the resurvey of these in 2007, when undertaking the Doncaster Geodiversity Assessment, I visited 3 sites on the Brotherton Formation – Skelbrooke quarry, Leys Hill quarries and The Dell quarry garden at Hexthorpe Flatts – and I also saw a small outcrop along Bubup Hill in Loversall, which was not on my list of sites to be surveyed, in addition to seeing it in the cutting when travelling by train from Rotherham to Doncaster

 

An extract from the geological memoir

 

The geological memoir for Goole, Doncaster and the Isle of Axholme says very little about the Brotherton Formation as seen at outcrop, mentioning that “Where exposed, mainly in old small quarries, the limestone is cream, yellow or buff, thin bedded and flaggy, commonly with grey and some red mudstone partings”. 

 

The BGS report on the Cadeby Formation

 

The British Geological Survey internal report (2005) on the building limestones of the Upper Permian Cadeby Formation further adds that “it generally only forms thin and very thin beds rendering it unsuitable for dimension stone. Locally it is used for walling and buildings along the outcrop, especially around Brotherton where it is currently worked for lime and building stone.” 

 

A view of the Skelbrooke quarry in 1997

When undertaking brief surveys of the quarries mentioned above, I didn’t spent any time looking for vernacular architecture in the vicinity but, even when looking at the quarry face from a distance at Skelbrooke quarry, I could see that the limestone was generally thin bedded and it was more suited to making lime or used as aggregates and industrial processes and not for building. 

 

A view of Skelbrooke quarry in 2007

At Leys Hill quarries near Brodsworth, most of the rock faces that I saw were dominated by very thinly bedded limestone that wouldn't even be suitable for dry stone walls, but in places the beds are thick enough to be used as coursed rubble for farm buildings and cottages in the vicinity. 

 

An old quarry face at Leys Hill

 

At Hexthorpe Flatts, the old quarry was transformed into a public park known as The Dell, which is now a Grade II Listed Park and I was able to get close to a bed of quite massive limestone that has a thickness of 20 cm and appears to possess physical qualities that would make it suitable as a general walling stone. 

 

An old quarry face in The Dell

 

During my travels in the previous year, I had been to Cusworth, Warmsworth and Sprotbrough, which are set on the Brotherton Formation and where all of the principal buildings - Cusworth Hall, Warmsworth Hall and St. Mary’s church - are built with limestone ashlar from the Cadeby Formation; however, if local quarries also had beds of 20 cm, I can’t see why these wouldn’t have been used in at least some of the agricultural buildings and cottages.

 

A detail of the old quarry face in The Dell

 

That said, in Warmsworth and Sprotbrough, which are also very near to quarries in the Cadeby Formation, I noticed that many of the cottages are rendered, which is not characteristic of settlements on the Cadeby Formation. This may reflect the fact that these buildings are built with poor quality thinly bedded limestone from the Brotherton Formation, with render applied to provide strength and durability.

 

An exposure of the Brotherton Formation on Bubup Hill in Loversall