﻿94 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [Feb. I905, 



followed by the borings made through the superficial deposits lying 

 along them. 



(v) That the maximum depth at which the rock-surface is met 

 below sea-level is 141 feet, and the greatest recorded thickness of 

 the superficial deposits is 233 feet. 



(vi) That the upper post-Glacial reaches of the Tyne, "Wear, and 

 other rivers are the same as the pre-Glacial, but that in their lower 

 parts numerous changes have taken place. 



(vii) That the drainage of the Magnesian-Limestone area of the 

 east of County Durham was in pre-Glacial times more distinct from 

 that of the west than it is now, since the Wear Valley has been 

 developed through it after the Glacial Period. 



(viii) That the present streams flowing over this portion of the 

 country are all post-Glacial, and have cut numerous, deep, gorge- 

 like valleys since the uplift that produced the raised beaches. 



(ix) That the elevation that caused these beaches was not uniform, 

 and appears to have been dome-shaped, reaching a maximum on 

 Fulwell Hills of 150 feet above the present sea-level. 



(x) That the dependence of the contour of the country on its 

 geological structure was much more pronounced in pre-Glacial 

 times than at present. 



(xi) That the superficial deposits are thickest along the pre- 

 Glacial valleys, and are not found above an altitude of 1000 feet. 



(xii) That a great thickness of the original superficial deposits 

 has been removed, and a varied series of derived formations 

 produced. 



In conclusion I wish to express my heartfelt thanks to Prof. 

 Lebour, who inspired this work, and who has by his constant 

 interest in it aided me in the carrying of it to a successful issue ; 

 to Prof. Watts for some helpful suggestions ; to Dr. J. A. Smythe, 

 who has been a companion in the field on numerous occasions, and 

 has discussed many a point with me ; and finally to Mr. M. Walton 

 Brown, Secretary of the North of England Institute of Mining and 

 Mechanical Engineers, who kindly granted me full permission to 

 make use of such maps and data as are in the possession of that 

 institution. 



IX. Bibliographical List. 



1. Wood, N., & Boyd, E. F. ' On a " Wash " or " Drift " through a Portion of 

 the Coalfield of Durham ' Trans. North of Engl. Inst. Min. Eng. vol. xiii 

 (1863-64) p. 69. 



2. Howse, B. ' On the Glaciation of the Counties of Durham & Northumberland ' 



Trans. North of Engl. Inst. Min. Eng. vol. xiii (1863-64) p. 169. 



3. Gbikib, J. ' The Great Ice- Age ' 1874. 



4. ' An Account of the Strata of Northumberland & Durham, as proved by Borings 



& Sinkings.' [Six Volumes.] North of Engl. Inst. Min. Eng. 1878-1897. 



5. Howse, B. ' Preliminary Note on the Discovery of old Sea-Caves and a Raised 

 Beach at Whitburn Lizards ' Nat. Hist. Trans. Northumberland, Durham, & 

 Newcastle-upon-Tyne, vol. vii (1880) p. 361. 



6. Lebour, G. A. ' Outlines of the Geology of Northumberland & Durham ' 

 2nd ed. (1886). 



7. Jukes-Browne, A. J. ' The Building of the British Isles ' 1888. 



