﻿64 DR. WOOLACOTT ON THE SUPERFECIAL DEPOSITS, ETC. [Feb. I905. 



7. The Superficial Deposits and pre-Glacial Yalleys of the 

 Northumberland and Durham Coalfield. By David 

 Woolacott, D.Sc, F.G.S. (Read November 23rd, 1904.) 



[Plate IX— Map.] 



Contents. 



Page 



I. Introduction 64 



II. The Nature of the Deposits 65 



III. The Distribution, Thickness, etc. of the Glacial Deposits. 72 



IV. The pre-Glacial Surface of the Country 74 



V. The pre-Clacial Valleys 75 



(a) The Tyne and its Tributary Valleys. 



(b) The 'Wash.' 



(c) The Upper Wear and its Tributary Valleys. 



(d) The ' Sleekburn Valley.' 



(Y) The Depression running out at Druridge Bay — 

 the ' Druridge Valley.' 



VI. General Remarks 86 



VII. Deductions 88 



VIII. Conclusions 93 



IX. Bibliographical List 94 



I. Introduction. 



Nearly the whole of the rock-surface of the Northumberland and 

 Durham Coalfield is covered by superficial deposits of an extremely 

 variable thickness. After I had made some study of the thickness 

 of these deposits and the pre-Glacial contour of the north-east of 

 County Durham, Prof. Lebour suggested to me that results of some 

 importance might be obtained from a thorough investigation of all 

 the borings and sinkings made in the Northern Coalfield, and the 

 working out of this subject has occupied the greater portion of my 

 leisure-time for the last three or four years. 



Nicholas "Wood &E. F. Boyd, in a paper on the 'Wash' published as 

 long ago as 1864 (l) 1 first clearly showed that the deposits covering 

 the rock-surface of this coalfield were not arranged in an irregular 

 manner, but were found along valley-like depressions. Since then, 

 little has been done towards the thorough elucidation of the Glacial 

 and superficial geology of this area. Indeed, little of a detailed 

 character could have been attempted until the publication in 1897 

 of the final volume of the ' Account of the Strata of Northumberland 

 & Durham, as proved by Boring & Sinkings ' (4). The six volumes 

 published by the North of England Institute of Mining & Mechanical 

 Engineers give details of 2,353 borings made in the Northern Coal- 

 field, or in its immediate neighbourhood. A large number of these 

 are useless for our present purpose, because their exact position is 

 not known, many of them are vague and indefinite, and some fail to 

 give the thickness of the superficial deposits. All, however, that 

 could possibly be of any service have been carefully analysed, and 



1 Numerals between parentheses refer to the Bibliographical List on pp. 94-95. 



