310 



GEOLOGY OF THE ISLE OF WIGHT. 



St. Helen's Fort. 1867? 



Sunk and communicated by Messrs. Docwra and Son. 

 brackets from an account communicated by Mr. Mylne.) 

 Bored throughout. 



(The words in 



Thickness. Depth 



Concrete ----- 

 Speckled sand - - - - 



Shingle and black pebbles 

 Grey clay (Yellow sandy clay, 57) 

 Peat (Black earth) . - . 



Greenish sand (Coarse green sand) 

 Stones (Flint gravel) ... 

 Greenish clay and shells 

 Pale green shell-marl (Shelly clay) 

 Green clay and shells (Hard green clay) 

 Claystone - - - - 



Grey clay and shells (Brown shelly clay) - 

 Claystone - - - - 



Green clay and shells - - - 



Stones - 



Dark green clay and shells 

 Claystone - - - - 



Green sand - . . . 



Green clay and pebbles - - - 



Grey sand - - - . 



Mr. Mylne's account is as follows, below 149 feet. 



Thickness, 



Claystone \ 



Hard blue clay/ 

 Limestone "1 



Green clayey sand J 

 Dark blue clay 

 Dark sandy clay 



Depth. 



Ft. 



154 



162 



168 

 170 



Spithead Defences — Horse Sand Fort. 



Communicated by Capt. Hewett, R.E., to H. W. Bristow. The fossils- 

 determined by Mr. Etheridge. 



Surface of shoal 24J feet below high-water of ordinary spring-tides. 

 Measurements from the Pump Room Floor, 3^ feet above high-water. 

 6 foot Cylinder to 83 feet ; the rest bored. 



Thickness. Depth. 



Recent 

 Marine De- 

 posits 70:t 

 feet. 



Water, &c. to surface of shoal 



Shingle and a little sand 



" Natural concrete " 



Clean shingle - 



Moderately fine sand and occa- 

 sional shingle, pieces of bark 

 and branches of trees - 



Shingle, sand and vegetable 

 matter, the latter almost entirely 

 compressing to centre dark band 

 [shown on the drawing sent] - 



Shingle, sand and shells - 



Blue clay, shingle and sand 



Pure sand 



Feet. 



271 



18 



14 



Feet. 

 32f 



50f 



58| 

 63f 



773. 



' ' 4 



78 



