Horace T. Brown — Boring at Stratford-on-Avon. 57 



Permian rocks of the Midland Counties, 1869, he gives the following 

 estimate of the thickness of the Keuper along this line : — 



Lancashire and Leicestershire and 



"W. Cheshire. Staffordshire. Warwickshire. 



Upper Keuper Marls ... 3,000 ft. 800 ft. 700 ft. 



Lower Keuper Sandstone ... 450 ft. 200 ft. 150 ft. 



Mr. H. H. Howell determined the thickness of the Upper Keuper 

 Marls east of Coventry and Warwick by measuring them across the 

 outcrop from their junction with the underlying Lower Keuper 

 to the overlying Rhaatic. He estimated the vertical thickness at 

 800 feet, and this estimate is strikingly confirmed by the results 

 both of the Rugby and the Stratfoi'd-on-Avon borings. The Rugby 

 boring was made in 1861, and, on reaching the Lower Keuper 

 Sandstones at 1,110 feet, was abandoned on account of the highly 

 saline properties of the water (see Rugby School Nat. Hist. Soc. Rep. 

 1868, p. 41). The Upper Keuper Marls were reached at 480 feet 

 from the surface, and were found to be 663 feet in thickness. 



Now, a line joining Rugby with Stratford-on-Avon intersects 

 Professor Hull's South-Easterly line of maximum attenuation almost 

 exactly at right-angles, and we should consequently expect the 

 thickness of the Upper Keuper along this Rugby-Stratford line to be 

 practically the same. Whilst at Rugby the thickness is 663 feet, at 

 Stratfoi - d-on-Avon the new boring has proved the Upper Keuper to 

 be 604 feet as a minimum. When to this we add the few feet 

 representing the very uppermost portions of the Keuper Marls, 

 which are not represented in the boring, and which probably 

 amount to from 25 to 30 feet, we find a very remarkable agreement 

 between the Rugby and Stratford data. 



South of Stratford-on-Avon the Trias has been reached at two 

 places by boring. At Mickleton in Gloucestershire, eight miles due 

 S. the Upper Keuper was struck at 1,285 feet, and penetrated for 

 57 feet, when the boring was abandoned. 



At Burford, Witney, 26 miles S. of Stratford, the Trias was 

 reached at 821 feet from the surface, and red beds to a total 

 thickness of 428 feet were passed through before the Coal-measures 

 were entered. The available descriptions of these Marls, Sandstones, 

 and Conglomerates, are unfortunately so vague that it is impossible 

 with any degree of certainty to differentiate the subdivisions of the 

 Trias, or to determine whether any portion of the rocks belong, as 

 in all probability they do, to the Permian. The best information 

 1 have been able to obtain is derived from a paper by Mr. De Ranee, 

 Trans, of Manchester Geol. Soc, vol. xiv (1877-8), p. 438. If the 

 cores of this boring, which was put down by the Diamond Rock 

 Boring Company, are still in existence, it is highly desirable that 

 the portion between the Rhaetic and the Coal-measures should 

 be subjected to a close examination by some geologist well acquainted 

 with the Trias and Permian of the Midland Counties. 



Mr. De Ranee, from the particulars given to him, estimates the 

 New Red Marls to be represented by 291 feet of the cores. 

 Assuming this to be correct we can now estimate the rate of 



