222 BR0WELL AND KIRKBY ON MAGNESIAN LIMESTONE 



undoubtedly often the case, though* not always, as shown by 

 analysis 36. 



It is of little or no use as a building stone. 



Sub-fokmation— UPPER LIMESTONE. 



Geological Characters, — Yellow, brown, and grey; friable, com- 

 pact, crystalline, and concretionary, the concretionary beds being 

 very remarkable on account of the peculiar forms taken by the 

 limestone ; in strata of various thickness up to three feet ; some- 

 times fossiliferous ; two hundred and fifty feet thick and more. 



No. 37. Locality— EULWELL QUARRY, 



SUNDERLAND. 



Lithological Characters (Botryoidal limestone). — Composed of 

 congeries of grey or yellowish crystalline, pea, or grape-like 

 bodies, imbedded in and with the interstices filled with a yellow, 

 impalpable powder or marl that is readily moved by weathering. 

 A common form of the concretionary beds of the Upper Lime- 

 stone both in this locality and on the coast between the Wear 

 and Tyne. 



ANALYSIS (of concretions only). 



Carbonate of lime 91 -95 



magnesia 2-06 



Sand, clay, oxide of iron, &c 5'26 



Water, &c 0-73 



100-00 



Nos. 38 and 39. Locality— EULWELL QUARRY. 



Lithological Characters. — Small spherical concretions of a grey 

 colour, imbedded in a light yellow matrix of soft "marl." The 



* The Middle Limestone of Humbleton Hill has been analysed by Dr. Thomson, Annals 

 of Philosophy, Vol. IV. 



Carbonate of lime 51-50 



magnesia 44-S4 



Insoluble matter 1-60 



Loss 206 



100-00 



