Pontefract Castle

Liquorice at Pontefract Castle

The 1940 edition of the British Geological Survey Memoir notes that the old mediaeval store houses of Pontefract Castle are hewn into Pontefract Rock, a massive - but loosely cemented - medium grained sandstone from the Pennine Upper Coal Measures Formation. 

Pontefract Rock

Pontefract Rock is generally buff/grey in colour, but it also contains partings of reddish-purple stained shale, from which the iron oxides have sometimes permeated into the body of the rock.

It is further recorded that much of the castle is built from this sandstone and that there are several old quarries on its north side so, having had a quick look at All Saints church, I set off up the hill to explore its rocky foundations. 

Having noted the principal physical characteristics of the sandstone that I had seen, I retraced my steps and walked up Castle Garth - where there is a mixture of stones - to see Pontefract Castle itself.

Building stones on the Garth

Completely destroyed at the end of the English Civil War, by the order of Oliver Cromwell himself, there isn’t much stonework to see apart from the remains of the keep; however, there is a good opportunity to study the characteristics of both the Pontefract Rock and the Magnesian Limestone, with the latter possessing a distinct yellow/orange colour here.

Carboniferous sandstone and Permian limestone at Pontefract Castle

With the first leg of my field trip now completed, I carried on up the hill to look at the various fine historic stone buildings that can be seen in the town centre.