Edivard Merrick — The River Tyne Drainage Area. 295 



head of the Redewater they are all members of the younger Palaeozoic 

 period, the youngest member of which, the Permian, covers but a very 

 small area on the East Coast. Up to the present no later deposits, 

 except the Glacial and post-Glacial deposits, have been discovered in 

 tbis area. 



In other parts of England — the Kent Coal-field, the Bristol Coal- 

 field, the Cottes wolds, and the Staffordshire Coal-field — the Mesozoic 

 deposits rest unconformably upon a junction-plane of Palaeozoic rocks, 

 the Trias being frequently the first unconformable deposit upon it. 



In South Durham there is no exposure of the junction of the 

 Permian and Triassic rocks, and there is some conflict of opinion as to 

 where the divisional line is to be drawn in some borings passing 

 through them. Still, for practical purposes, the Tyne area may well 

 be regarded as a continuation of this junction-plane which has been 

 eroded into the present system of hills and valleys. Placing the 

 formation of this junction-plane, peneplain, or surface of planation — 

 whatever the causes were which produced it — as originating about 

 this time, it follows that it was probably affected by the later move- 

 ments proved in adjacent areas, and that such movements were liable 

 to follow the same general trend and lines of weakness as the pre- 

 Permian movements. Something of this kind must have taken place, 

 for when walking westwards along the left or north bank of the 

 River Tyne it is noticed that the surface-levels of the country to the 

 north are typically lower than on the south or right bank, and that 

 this difference continues to increase on walking westwards. In other 

 words, the Durham side of the river has higher contours than the 

 Northumberland side. 



The following Table of Levels, taken from the 1 inch Ordnance 

 Survey Maps, illustrates this difference. The most easterly stations 

 are at the head of the list : — 



TABLE I. 



Left Bank. 

 Tynemouth l 

 Moorhouses 

 Scaffold Hill 

 Byker Hill 1 

 Condercum 

 Westerhope 1 

 Heddon Laws 



Harlow Hill 



Kip' Hill '.' 



" 1 

 Little Whittingham 



Land Levels in Feet. 



Height. Difference. Height. 



120 

 242 

 253 

 214 

 409 

 435 

 501 



554 

 649 



689 



Eight Bank. 



157 111 Cleadon. 



65 307 Down Hill. 



3 250 No hill, but rising ground. 



286 500+ Beacon Lough. 



290 700 Tinkler Bow. 



314 749 Near west of Sandy Gate. 



84 585 High Spen. 



404 905 Billingside. 



534 1,035 Pontop Pike. 



296 851 West of Currock Fell. 



76 620 Near Edgwell House. 



311 960 - Kilnpit Hill. 



264 913 No name. 



582 1,231 Stoterley Hill. 



571 1,260 Edmundbyers Common. 



343 1,032 Pit House Fell. 



1 Picking out the five marked hills as least denuded. 



