What Does a Geologist do for a Cathedral?
Dr Michael Ashton, Ashton Geology Ltd
Lincoln Cathedral is unique amongst the great English Gothic Cathedrals in being built of the stone upon which it rests and working its own quarry that provides that stone. For the last 150 years the 'Lincoln Stone' used for the renovation and maintenance of the cathedral has been quarried from the Dean and Chapter Pit in the northern part of the city. The recent decommissioning of the quarry has presented Chapter with a series of new challenges centred around replacing the stone supply: whether to replicate the current quarry installation, or to seek external supplies of 'Lincoln Stone' or to use other UK or foreign sources of stone. These decisions are complicated by contrasting views on whether 'Lincoln Stone' is confined to the City of Lincoln area. Part of the dilemma revolves around the parochial terminology applied to building stones compared to that used for their 'geological host formations'.
In this talk I will illustrate the range of masonry and conservation skills that are applied in maintaining the fabric of Lincoln Cathedral, before characterising geologically the 'Lincoln Stone' and placing it in its broader stratigraphical and depositional context within the Middle Jurassic Lincolnshire Limestone Formation. From this sedimentological vantage point I will discuss examples of how the pure geology can be used to guide the applied needs of the Cathedral either in the search for any potential new quarry site or the evaluation of externally sourced building stones of local or foreign origin. Finally, I will propose how the conflicts of terminology and understanding can be resolved through the development of a stone characterisation archive that can underpin decision making around the Cathedral's fabric activity in the future.
In late2017 , Mike Ashton retired from the company he founded with Michael Badley in 1982: Badley Ashton and Associates Ltd, which supplied reservoir description skills and training to the oil industry worldwide with offices in Oman, Abu Dhabi and, since 2003, a subsidiary, Badley Ashton, America, Inc in Houston, Texas. From 2002 to 2017 Mike was primarily based in Houston working on deepwater reservoirs in the Gulf of Mexico, offshore areas of Australia, Malaysia and Africa, and the eastern Mediterranean principally for BP, Shell, Noble Energy, British Gas and Hess.
Since retirement he has shared his time between consultancy for his former company and his voluntary work for the Heritage Trust of Lincolnshire and Lincoln Cathedral. The latter has involved a return to his first geological love, the Lincolnshire Limestone Formation, retracing and re-evaluating his Ph.D from a building stone perspective. Mike has authored over 240 technical reports for the oil industry and published six papers on various aspects of the Lincolnshire Limestone's bio- and lithostratigraphy and depositional development.