DERWENTHAUGH LAND IN DERWENT GUT. 425, 



denudation, so that a large period of time parts the two lower 

 clay deposits, the boulder clay and the Birtley brown clay. 



Above this brown clay comes a bed of wet hard gravel 

 and sand of an average thickness of 8-ft. 8J-in., parting the 

 great clay stratum from another of soft blue clay and river 

 mud with average thickness 33-ft., and above which lies a 

 yellow clay and surface soil of an average thickness of 5-ft. 2-in. 

 This gravel and sand deposit shows variations which indicate 

 just as we might expect, shifting currents, in first, the rough 

 gravel and sand of No. 9 hole; in second, the very rough 

 gravel and sand of No. 6 hole ; in third, the gravel without 

 sand of No. 12 hole; in fourth, the 6-ft. sand over the 62-ft. 

 gravel of No. 10 hole; and fifth, in the 3-ft. of loamy sand 

 above the usual sand and gravel of No. 7 hole. In this upper 

 bed of clay and river-mud appears, in all the holes except 

 Nos. I and 5, a peat-bed of maximum thickness 6-ft. 9-in., 

 and average thickness 4-ft. 3i-in,, capping the bed. 



Now here we have a succession of deposits of gravels and 

 muds, and shall do well to remember that deposition of gravels 

 points to times of energetic action and shallow waters, and 

 muds to quiet times and deep waters. There were three such 

 times of energetic action, one in the very beginning of the 

 filling up of this rock-bed exceptionally active, for among the 

 pebbles are many considerable boulders ; and another between 

 the boulder and brown clays ; the third when the filling up 

 work was two-thirds done and its energy was getting spent, 

 for the stones here are true pebbles, such as we may find 

 to-day in any of our river beds. There is considerable ground 

 for believing that the first of these marks the beginning of the 

 retirement, the second a genial interval, and the third the end 

 of the retirement of the Glacial age in our county, and the 

 presence of that whinstone boulder in No. 3 hole confirms 

 this. The brown clay is therefore a Till. 



In more quiet time's, and with ameliorated climate, the 

 upper soft clay was laid down, that bed which yet bears its 

 last cap of verdure in the peat-bed which underlies the present 

 soil some 5 or 6 feet. ■ 



