298 Edward Mwrick — The River Tyne Drainage Area. 



near Tynemouth the two banks of the Tyne are at different levels, as 

 already shown in the above table. This would seem to indicate by 

 its influence on the Tyne banks that the He worth 25 fathom dyke, 

 rather than the Ninety Fathom Dyke, is to be considered as the 

 easterly continuation of the Stublick Dyke, for it extends the 

 difference in levels produced by that dyke. This would also indicate 

 that the Ninety Fathom Dyke is the oldest of the three faults. 



6. The general strike of the strata does follow that of the restored 

 contour-lines. 



7. The restored contour-lines, up to 300 feet in the eastern area, 

 are fairly concurrent and in general trend follow that of the present- 

 day coastline. 



8. The main valley of the Tyne is concurrent with the Stublick 

 and Heworth dykes, and is therefore very straight. 



If a line be drawn on the north bank of the river from Fourstones 

 Railway Station to the Coastguard Station at Tynemouth, then the 

 river lies wholly to the south of it ; similarly, the river lies wholly to 

 the north of a line drawn on its south bank from Stocksfield to 

 Heworth Shore. On drawing a line half-way between these two 

 boundary-lines, the mean course of the existing river is obtained. 

 From this line the windings of the river are measured in the 

 following table, the easterly stations being at the head of the list: — 



TABLE III. 



Locality. Deviation or Winding. 



Tynemouth . . .1-8 miles north 

 Heworth Shore . 



Team Mouth 

 Stocksfield 

 Fourstones Station 



1-9 ,, south 



1-775 



2-125 



2-275 



north 



Maximum winding . 4-4 miles in all. 



The north and south bounding-lines diverge westwards and are cut 

 off by the Pennine Fault and Triassic deposits. 



It is rather peculiar that Condercum — 409 feet — lies near the mean 

 course of the river, and that there is no land north of it which reaches 

 this height. Byker Hill is also in a similar position. Condercum is 

 on the south or upcast side of the Ninety Fathom Dyke, and stands 

 upon sandstone, of which material Byker Hill is also composed. The 

 strata dip gently from these two hills towards the present position of 

 the river. Denudation beginning in the softer materials above this 

 sandstone has worked southwards and cut downwards till the present 

 river valley was formed, leaving these hills as monuments of the 

 former height of the land. It is not necessary to conclude that these 

 hill-tops were actually the bed of the river in times past, for the mean 

 course of the river is drawn, not from the past, but from the present 

 windings of the Tyne. 



B. The "Watersheds South of the Main Yalley. 



On going along the foot of the Cross Fell escarpment from north 



to south, the solid rocks are seen to have been faulted down to the 



west, while those on the east or upcast side have been bent into an 



anticlinal arch. Consider what the effect of this combined movement 



