KIMERIDGE CLAY. 



333 



iron. The usual yield of ore per diem at these works is 300 tons, which are 

 smelted at the fine blast-furnaces adjoining.^ 



In Yorkshire the Lower Calcareous Grit yields building-stone and road-metal ; 

 there are quarries at Castle Howard, etc. The Lower Limestone is extensively 

 quarried and burnt for lime. The Greystone is quarried for building walls and for 

 road-metal ; near Hackness it is known as Wallstone ; and at Gaterley it is burnt 



Fig. 49. — Section from Abbotsbury to the West Fleet, Dorsetshire 



(R. Damon.) - 

 S. 



Abbotsbury -nt 

 Common. 



Linton Hill. 



Abbotsbury. 



Wall Down 



e. Oxford Clay. 



f. Cornbrash. 



g. Forest Marble. 



a. Chalk. 



b. Upper Greensand. 



c. Kimeridge Claj'. 



d. Corallian Beds. 



for lime. The Middle Calcareous Grit has been quarried at Pickering, and Wass 

 Moor. The Upper Limestone is quarried at Pickering for lime-burning and as a 

 flux for smelting iron-ore ; it is also used for road-metal. Mr. Strangways 

 mentions that the old cavern of Kirkdale is almost quarried away. 



Near Oxford, the Headington Stone, which consists of 12 feet of Oolitic freestone, 

 has been worked for building-purposes ; the stone is also quarried at Faringdon, 

 Cumner, and Wheatley ; it is, however, nowhere very durable. Many of the 

 Colleges at Oxford were built of Headington Stone. At Calne (Calne freestone), 

 Goat Acre, north of Hillmarton, again near Gillingham, Todbere (Todbere stone) 

 and Marnhull, stone has also been worked for building-purposes, or road-metal. At 

 Westbrook north of Seend, the stone (Westbrook rag), has been burnt for lime ; 

 and at Westbury the limestone is quarried as a flux for smelting the iron-ore. 

 Near Weymouth clay-beds are worked for brick-making. The Sands are dug in 

 many places. 



The Corallian series furnishes a light sandy and brashy arable soil ; the 

 pasture is poor and the soil unproductive in some localities. The Corallian beds as a 

 rule are water-bearing strata. In some places, as in a well-boring at Swindon, and 

 near Wootton Bassett, saline waters have been met with.'' 



UPPER OOLITIC. 

 KIMERIDGE CLAY. 



The Kimeridge Clay consists of dark bluish-grey shaly clay, 

 which is sometimes bituminous. Crystals of selenite are not un- 

 common. The clay is occasionally calcareous ; it contains nodules 

 of argillaceous limestone or septaria, and sometimes sandy beds 



^ Blake and Hudleston, Q. J. xxxiii. 2S4 ; A. C. Cruttwell, Geology of Frome, 

 p. 18. 



^ Geol, Weymouth, etc., p. 52. See also De la Beche, T. G. S. (2), iv. plate ii. 

 3 Q. J. xlii. 298. 



