A. J. Julies Browne — On tlie Upper Greensancl, etc. 353 
Feet 
Upper ( Parallel layers of soft rock and of hard cherty sandstone 37 
Greensand ( Sand with layers of stone and chert ... 67 
— 104 
r u | Light-coloured Gault becoming bluer 43 
| Beds of decided blue colour .. 103 
146 
Lower Greensand in various beds ... 
250 
These measurements and divisions, although apparenfly taken 
with great care, do not seera at first siglit to correspond with those 
given in the Survey Memoir on the Isle of Wight; but it is re- 
markable that the combined thickness of the Gault and Upper 
Greensand should be estimated in both at exactly the same amount, 
viz. 250 feet. Of this, 150 feet are assigned to the Greensand by the 
Geological Survey, including 50 feet of clayey micaceous sands at the 
base. Now I think it is not improbable that these are the “ light- 
coloured Gault ” mentioned in the above section, which, if added to 
the other beds, makes the thickness very nearly the same, viz. 147 
feet. This is of course a conjecture ; but as they are certainly 
passage-beds, it would not be surprising to find them placed in the 
lower formation by some authors, and in the higher by others. 
Captain L. L. B. Ibbetson seems also to have excluded these beds, 
when he states that the Upper Greensand is about 100 feet thick ; 1 
he does not mention the locality where this was measured, but he 
gives a detailed list of the strata observed in descending Order ; as 
this has never been reproduced elsewhere, I give the following 
abridgment of it : — 
ft. in. 
f 1. Zones of Cbert and Rag, with Pecten orbicularis, P. 5-costatus, 
) Serpula concava and Siphonia ... ... ... ... 15 0 
4 2. Conglomerate of Chert and Rag (much rolled) 4 0 
| 3. Bands of Chert and Firestone ... 5 2 
4. Freestones separated by layers of Rag 11 6 
f 6. Rag and Malm alternating 16 8 
j 6. Mammillary Rag, round Chert, sandy boulders, with phos- 
j phate of lime ( P nodules) ...’ 1 6 
i 7. Malm and Rag 6 8 
| 8. Fossiliferous Malm ... .. 3 0 
t. 9. Malm and Rag, with numerous Serpulce 40 0 
103 6 
The close agreement of this section with that of Mr. Simms is 
made more apparent if it is still further abbreviated thus : — 
ft. in. 
Zones of Chert, Firestone and Freestone 35 8 
Alternations of Rag and Malm 67 10 
103 6 
and it is possible therefore that the thicknesses were estimated at the 
same place, viz. at St. Catherine’s Down. 
About the same time (1S4S) Messrs. Paine and Way published an 
important paper on the Phosphatic Strata of the Chalk Formation/ 
1 Notes on the Geology and Chemical Composition of the Yarious Strata in the 
Isle of Wight, London, 1849. 
2 Journ. Roy. Agric. Soc. ser. i. vol. is. p. 56. 
DECADE II. — VOL. IV. — XO. VIII. 
23 
