606 



MR. P. G. H. BOSWELL ON THE 



[Dec. 19 1 3, 



cortex. Others are subangular, in the process of being rounded off, 

 their edges smooth, but their substance still unaltered. Mr. Slater 

 also secured one well-rounded pebble of Jurassic limestone. The 

 appearance of these rocks, from their shape and lack of alteration, 

 at once suggests pot-hole action ; but pot-hole action where Eocene 

 and Crag detritus had no entry, for there is an entire absence of 

 iron-staining. Very different are the terrace-gravels, also the 

 glacieluvial gravels, with their intensely iron-stained and battered 

 flints, and the ' Cannon-Shot ' Gravels, with their ferruginous flints 

 often beautifully rounded, as our specimens are. 



It is possible that the flint-gravels so frequently noted at the 

 base of other buried channels may be similar, but the well-sinkers 

 would probably not record the difference in character of the pebbles. 

 In normal sections in the district a band of glauconitic green-coated 

 flints, of the usual irregular shape, generally occurs at the base of 

 the Thanet Beds, lying directly upon the Chalk. 



Table of Borings in the Gipping Valley — Lower Portion. 



Bramford Chalk-pits ' 100+ — 



Sproughton Clav-pit ■ — — 



Ipswich— Henley Road : 150+ 136 1 



Do. Tollemache's 35 35 



Do. Cliff Brewery \ 34 34 



Do. Co-operat. Society, Carr St. 40 42 



Do. Stay Factory i 47 52 



Do. Unicorn Brewery 26 32 



Do. Burton's Jam Factory '' 16 35 



Do. Mason's Paper Mills 13 29 



Do. Keavell's Works 1 18 34 



Do. Gas Company, Holy wells....' 27 37 



Do. Orwell Works 12 32 



Do. Near Cliff Brewery ! 18 



Do. Fison's Works 12 30 



Do. Waterworks 25 27 



Do. Stoke Uni^n 40 60 



Do. Waterside Works 15 t 20 & 26 



Do. South of Key Church 11 61 



Do. St. Peter's Works 12 70 



Do. Cranfielrls 10 127 



Do. College Street 14 130 



Do. Gas Company, Patteson Rd. 14 90 



Do. Diesel Work's 23 113 



Do. Smart's Wharf 13 40^ 



Do. Old Dock borings Manybelow — 



6.D. 



Do. New Dock borings, average... do. — ! —25 to —32 



Rushmere ■ 82 114 x -32 



Woolverstone 95 305 1 -- 10 



Butterman's Bay — — I Below —40 



+ 100 

 + 50 

 + 14 

 + 



+ 



- 19 



- 16 



- 16 



- 10 



- 20 



- 18 



- 18 

 _ 2 



- 20 . 

 -5&-9 



- 50 



- 58 

 -117 

 -116 



- 76 



- 90 



- 27* 



■ 13 to -60 



1 Includes Eocene beds and Crag also. 



