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| The transepts at Roche Abbey |
Leaving Stone and walking westward towards Roche Abbey, Firbeck Dike is now seen to flow through a wide and shallow valley that has a completely different character, with the woodland being replaced by open grassland grazed by horses.
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| A view along the valley to Roche Abbey |
The only outcrops of Permian dolomitic limestone seen at its east end are a few isolated crags on its upper slopes, which are in places partly overgrown, but these show that the limestone here is laid down as thick, massive beds in which solution cavities have since developed.
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| Massive beds of limestone with solution cavities |
Continuing along the path for a couple of minutes, the impressive remains of the transepts of Roche Abbey soon come clearly into view – the only substantial parts left of the abbey after its dissolution in 1538 and subsequent pillaging, which was described by Michael Sherbrook – the rector of Wickersley who witnessed this despoliation.
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| A view of the transepts and crags at Roche Abbey |
The abbey is set on low lying land at the confluence of Hooton Dike and Maltby Dike, which served the day to day needs of the Cistercian monks, including the powering of mills; however, in the C18, the 4th Earl of Scarbrough commissioned Capability Brown to landscape the site, including the burial of the ruins under mounds of earth, but the site has been since excavated during the 1920’s.
To the north side of the transepts, there is a resumption of the crags, which continue for some distance to the west past the abbey and were once the site of the Roche Abbey Quarries - now frequented by rock climbers. The quarries were not only the source of stone for the abbey, but they also supplied the stone for several other mediaeval churches in the region and for work at Sheffield Castle and Windsor Castle.
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| Dolomitic limestone crags at Roche Abbey |
The limestones here, which are quite high up in the sequence of the Cadeby Formation, appear from a distance to be similar to those seen at Stone, with thick bedded massive limestones again being the dominant strata.
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| Thick beds of massive limestone at Roche Abbey |
Although it is the Wetherby Member of the Cadeby Formation that outcrops here, as shown below in a sketch map of the Permian rocks in the district, the geological memoir suggests that some of the granular beds in the quarries and crags should be classed in the upper subdivision – the Sprotbrough Member.
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| A sketch map from the 1957 geological memoir |
Over the years, while undertaking surveys of RIGS (Regionally Important geological Sites) in South Yorkshire and during subsequent investigations in West Yorkshire and Derbyshire, I have visited more than 40 sites on the Magnesian Limestone.
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| An extract from the 1957 geological memoir |
Using the generic descriptions in the Geological Survey of Britain memoirs as a starting point, I have encountered most of the lithological characteristics mentioned and, with this formation often being extremely variable from place to place, I still find it to be full of surprises.
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| A section of limestone at Roche Abbey |
At Roche Abbey, there is considerable variation between the lithologies seen in the lower and upper parts of the section, which exceeds 15 metres in places, and a proper understanding of it needs a detailed survey.
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| A section of limestone at Roche Abbey |
With many other people, mainly teenagers from Maltby, taking advantage of the sunshine during the school half term, I didn’t want to attract attention by wielding my Estwing hammer too openly, but I did discreetly collect a sample from the crags nearest to the path.
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| A sample of limestone in bright and dull light |
This was taken from a section with thin rubbly beds, with the limestone appearing quite grey in colour and very fine grained, which indicates that it was deposited in an environment such as a lagoon, where the sediment was not affected by strong currents or wave action.
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| The gatehouse at Roche Abbey |
Having obtained a sample of limestone for my growing collection of rocks, I continued past the remains of the gatehouse, where part of the ashlar masonry has been removed to reveal a rubble core, before heading off to the next stop on my walk – Maltby Crags.
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| An exposed core of rubble masonry |
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