Alluvium 



and 

 Terrace. 



604 MR. P. G. H. BOSWELL ON THE [Dec. I9I3, 



feet O.D. Along the broken lines on the map, near the Dock- 

 entrance, there seem to be hollows in the Chalk : that on the west 

 being indicated by the old series of borings, that on the east being 

 indicated by the new. However, the hollows do not appear to be 

 of any great extent or importance, though they may be the end of 

 the proved deep channel. The well-boring for the Gas-Works in 

 Patteson Eoad (1905) yields evidence of a Drift-filled hollow, 

 but whether it is connected with the deep channel, or with the 

 minor channels at the Dock-entrance, we do not know. The 

 particulars of the boring are : — 



Ground-level +14 feet O.D. 



Thickness in Depth in 

 feet inches, feet inches. 



Made soil 5 6 5 6 



Coarse ballast, 3 8 6 



Black mud 3 11 6 



Coarse dark ballast 11 6 23 



/'Light loam 4 6 27 6 



I Running sand 8 35 6 



| Dark loam 6 41 6 



j London Clay 1 2 43 6 



Loam sand 6 6 50 



Dutft J London Clay 1 5 9 55 9 



^ RirT - ) Loam and sand 9 6 65 3 



Light-brown clay 9 66 



j Flint-bed and gravel 18 84 



I Light coarse sand 2 86 



I Sandstone 1 87 



^Fiint-bed 3 90 



Chalk 160 250 



Surface of Chalk -76 feet O.D. 



If the hollows indicated by the Dock-borings and this Gas-Works 

 boring are connected with the proved deep channel, the result 

 would be interesting, as their direction is at right angles to that 

 of the proved channel, and it would indicate that the hollow 

 changed direction sharply with the present estuary. Until recently 

 there were two anomalous borings reaching Chalk at considerable 

 depths only. The details of the strata bored through have been 

 frequently reprinted, 2 and it is unnecessary to give more than a 

 summary here : — 



(1) College Street, Messrs. Burton $ Saunders. (14 feet O.D.) 



Feet. 



Drift 130 



Chalk 191* 



Chalk-level -1160.D. 



(2) St. Peter's Quay, Messrs. Cranficld. (10 feet O.D.) 



Feet. 



Drift 127 



Chalk 81 



Chalk-level -117 O.D. 



1 The well-sinkers' term only. The grouping of the beds is mine. 



2 Mem. G-eol. Surv. 1906 (2i) p. 74, etc. 



