82 



J. G. GOODCHILD ON THE GLACIAL PHENOMENA OE THE 



1 

 <3 



as 





If 





From evidence that will be referred to again it 

 is almost certain that these great rock- basins 

 could not have been filled with water to any 

 depth while the drifts were being deposited, 

 although the presence of alluvial terraces high 

 above the present beds of the rivers of that 

 part seems to point to the existence of a shallow 

 lake of considerable extent in postglacial times, 

 which may have been due to the presence of a 

 barrier of drift mounds ponding back the na- 

 tural drainage of the district. It is only referred 

 to here because the rock barriers must have 

 acted as bars to keep the sea out below the 450- 

 foot contour, so that the absence of any thing 

 at all resembling marine Boulder-clay above 

 them is easily enough accounted for. 



The cuttings now being made along the 

 Settle and Carlisle Eailway in the Eden valley 

 afford some very instructive sections in the 

 drifts. Above Culgaith there is not much that 

 calls for any particular remark ; but at the 

 north-western end of the tunnels between that 

 village and Longwathby the railway crosses the 

 axis of a drumlin at a small angle, so that a 

 very instructive section is laid bare. At the 

 south-eastern end till, with the ordinary far- 

 travelled boulders of the Eden-valley drifts, 

 and obscurely stratified, is seen overlying beds 

 of " marl" belonging to the middle division of 

 the red rocks of the Eden valley. Overlapping 

 the till is a series of alternations of diagonally 

 bedded sands and gravels with finely laminated 

 clays. Another mass of till, which is quite un- 

 distingnishable from that seen at the base of 

 the series, covers all the beds from the northern 

 end of the cutting to the solid rock. Fig. 2 

 will perhaps serve to make this clearer*. 



The most remarkable point about the whole 

 series of deposits is the singular uniformity of 

 inclination of all the beds below the upper 

 till that show traces of stratification. Some 

 of the beds of laminated clay are seen lying 

 at angles of from 25° to 30°, and in some 

 instances at even higher angles than that, 

 proving, beyond the possibility of a doubt, 

 that they could not have been deposited under 



* In the woodcut the gravels at the left hand of the 

 section are represented as too highly inclined. The 

 true inclination is nearly that of the base line of the 

 overlying till. 



