486 



ME. A. STKAHAN ON THE LINCOLNSHIEE CARSTONE. 



39. Notes on the RELATioj^fs of the Lincolnshiee Caeston^e. By 

 AuBEET Strahan, Esq., M.A., P.G.S., H.M. Geological Survey. 

 (Eead June 23, 1886.) 



(Communicated by permission of the Director-General.) 



The Carstone of Lincolnshire lies immediately below the E,ed Chalk, 

 and rests upon the fossiliferous clays and limestone known as the 

 Tealby Beds. The Tealby Beds were described in detail for the 

 first time in 1867 * by Professor Judd ; and their relations to the 

 Speeton section, and to beds of the same age throughout Northern 

 Europe, were discussed in 1870 f by the same observer. In 1883 

 the survey of the district was completed, with the result of 

 verifying in almost every particular the conclusions which had been 

 so ably worked out by Professor Judd. On one point only I 

 ventured to form a somewhat difierent opinion, namely on the 

 relations of the Carstone to the Bed Chalk above and to the Tealby 

 Beds below. 



The following table gives (in brief) the correlations advocated 

 by Prof. Judd, and shows also the names of the various sub- 

 divisions which have been adopted for the Survey publications, and 

 which win be used in this paper : — 





Judd. 

 Yorkshire. 



Judd. 

 Lincolnshire. 



Survey Nomenclature. 

 Lincolnshire. 



Gault 



Hunstanton 

 red rock. 



Hunstanton 

 red rock. 



Red Chalk. 



Carstone. 



% r LTpper Ironstone and Clay. 



f^ J Tealby Limestone. 



^A Tealby Clay. 



'^ [_ Lower or Claxby Ironstone. 



Spilsby Sandstone. 



Neocomian J 



Middle \ 

 Neocomian J 



Lower 1 

 Neocomian j 



Uncon 



formity. 



O 



(D 



1 



(^ Clays, &c. 



Clays, &c. 



^ Clays, &c. 



Upper Sands 



Tealby Series. 



Lower Sands and 

 Sandstone ? 



The Carstone, which was doubtfully correlated with the Upper 

 Neocomian of Speeton, was believed by Prof. Judd to be quite 

 unconformably overlain by the Bed Chalk. This theory of an 



* *' On the Strata which form the Base of the Lincolnshire Wolds, 

 Journ. Geol. Soc. vol. xxiii. pp. 227-251. 



Quart. 



t " Additional Observations on the Neocomian Strata of Yorkshire and 

 Lincolnshire, with Notes on their Eelations to Beds of the same Age throughout 

 Northern Europe," Quart. Journ. Geol. Soc. vol. xxvi. pp. 326-347. 



