DERWENTHAUGH LAND IN DERWENT GUT. 423 



and 126-ft., with slope toward the Tyne westwardly, and 

 reveal part of an olden mouth of the Derwent, which ended 

 then as now in the Tyne, somewhere N.W. of No, i hole, 

 and deeper than 150-ft. below the present surface, which is 

 only 6-ft. above high-water mark at the present day in that 

 river. This trough was about 3 fathoms deep, and can be 

 traced upwards through the varying deposits, thus linking 

 past and present. 



These 12 borings, therefore, place beyond all doubt the 

 facts that the Derwent has followed roughly its present course 

 for a very long period, and did so at a time when the surface 

 was at least 150-ft. higher than it is now — that it subsequently 

 filled up the rock-bed with the present alluvial deposits in 

 consequence of a gradual sinking of the whole N.E. coast in 

 this neighbourhood. Nay, these borings do much more than 

 this, for the alluvium is not uniform ; its character changes 

 several times most markedly and apparently abruptly, and in 

 these changes reveals to us climatal and surface variations, 

 thus preserving to us a record, which once read extends the 

 history of Derwent-dale back many centuries, probably many 

 thousands of years, and with it the history of the Tyne ; takes 

 us back in fact to the earlier and most energetic ages of the 

 last Glacial period, for ice, so far as we know, is the only 

 physical agent capable of scooping out such a rock-bed as is 

 revealed here in Derwent Gut; and running water is the 

 only agent likely to have filled that Gut up with its present 

 alluvium. 



The deposits in Derwent Gut fall into six natural groups as 

 follows : — 



1. Soil with average thickness nearly 2-ft. 2-in., maximum 



4-ft., and minimum i-ft. 2-in. 



2. River Muds and Peat, average 35-ft. 6-in., maximum 



44-ft., and minimum 28-ft. 2-in. 



3. Hard Gravel and Sand, average 9-ft., maximum 



14-ft. 2-in., and minimum 2-ft. 4-in. 



4. Brown Clay, average 64-ft. 6-in., maximum 88-ft. 8-in., 



and minimum 54-ft. i-in. 



