PERMIAN. 219 



Dolomieu. Hence the Upper Permian rocks are sometimes termed the 

 Dolomitic Series. An analysis of Bolsover stone showed the following com- 

 position ;! — 



Carbonate of lime 5 ' ' ' 



Carbonate of magnesia 40^2 



Oxide of iron and alumina i '8 



Silica 3"6 



Water and loss 3'3 



It is sometimes globular or botryoidal^ in structure ; and this, as remarked by 

 Sedgwick, is seen in its most imposing form on some parts of the coast of Durham, 

 where the whole cliff resembles a great irregular pile of cannon balls. 



The laminated limestone of Marsden, near Sunderland, yields a variety of flexible 

 limestone, very fine specimens of which occur in a bed near the middle of the 

 cliff near Marsden Rocks. Some beds in Yorkshire are fetid. 



The Magnesian Limestone has been largely quarried at P)olsover Moor in 

 Derbyshire, from which locality some of the stone used in the construction of 

 the Houses of Parliament was procured. There is about twelve feet of workable 

 stone, of a pale brownish-yellow colour, hence it is locally called Dunstone. As a 

 building-stone for plain or ornamental work the Bolsover stone is, under ordinary 

 circumstances, an exceedingly durable stone : the more perfectly crystalline 

 varieties being esteemed the best, for some beds are liable to comparatively rapid 

 decay. Intercalated among the beds of good stone are others of inferior quality, 

 some of which weather into "Rustic work." Much of the stone used in the 

 Houses of Parliament was brought from Huddlestone and the North Anston 

 quarries ; the lower part only of the Palace of Westminster being built of the 

 Bolsover and Mansfield Woodhouse Stone, which was that chosen by the Royal 

 Commissioners.^ In the quarries at Mansfield Woodhouse the stone is opened 

 up to a depth of 60 or 70 feet. Mr. J. W. Kirkby has remarked that notwith- 

 standing all the obloquy that has been thrown upon the Commission appointed to 

 select the building-stone, for fixing upon a Magnesian Limestone, yet there can 

 be no doubt they were right in their choice, the fault not being in the stone 

 chosen, but apparently in the neglect of the architect in not seeing that it was taken 

 from the right beds.* 



Southwell Minster was also to some extent (the Norman portions) constructed 

 from the Bolsover stone, and partly from that at Mansfield. Quarries have been 

 largely worked at Conisborough, Roche (or Roach) Abbey, near Bawtry, in 

 Yorkshire ; also in the neighl)ourhood of Doncaster, at Brodsworth, and Park- 

 nook, Steetley near Worksop, Shireoaks, Kiveton, etc. 



The stone employed in the Museum of Practical Geology was obtained at 

 Anston ; and that used in the construction of Westminster Hall was obtained at 

 Huddlestone. Jackdaw Craig, near Tadcaster, and Smawse on Bramham Moor, 

 are well-known localities for this building-stone. York Minster was partly con- 

 structed of stone from Jackdaw Craig, and Beverley Minster of stone from Smawse. 

 The stone is quarried at Bulwell and Kimberley near Nottingham, furnishing 

 building and paving-stone, road-metal, and being sometimes used for making 

 troughs, etc. There are quarries also at Sutton-in-Ashfield. 



Besides the yellow crystalline limestone of Mansfield Woodhouse there are in 

 that neighbourhood red and white dolomitic sandstones, which are probably on 

 the same horizon, and are only siliceous varieties of the Magnesian Limestone. 

 They have been much quarried for building-purposes, and are known as the 



1 R. Hunt and F. W. Rudler, Descriptive Guide to the Museum of Practical 

 Geology, edit. 4, p. 40 ; see also W. T. Aveline, Explan. of Sheets 71 N.E. and 

 b2N.E. and S.E. (Geol. Survey.) 



- A term applied to an assemblage of concretions resembling a bunch of grapes. 



=* Explan. Sheet 82 N.E. (Geol. Surv.), by W. T. Aveline. 



* Q, J. xvii. 292. 



