SIMMS ON THE LOWER GREEN SAND. 



77 



exceedingly well defined at Atherfield Point. That of the lower 

 green sand with the gault, though not quite so obvious as the 

 last-mentioned junction, is yet very satisfactorily ascertained — 

 1st, Below the Hotel at Black-gang-Chine, where the green sand 

 forms a line of terrace projecting beyond the gault ; 2dly, On the 

 cliff eastward and immediately above Black-gang-Chine, where 

 gault fossils occur at the very point of junction with the lower 

 green sand. The junction of the gault with the upper green 

 sand is well defined on the face of the cliff south of St. Cathe- 

 rine's Down, east of the Sand-Rock Spring, and above the road 

 leading from Black-gang-Chine to Ventnor. The junction of the 

 upper green sand with the white chalk marl is very well marked, 

 near the summit of the same cliff. 



The author stated that in the section, drawn according to scale, 

 which accompanied this notice, he had given, not only the three 

 principal groups, but also their more remarkable and best defined 

 subdivisions, without pretending to describe, in needless detail, all 

 the strata of which they are composed. From the particulars 

 which he subjoins respecting these subdivisions, the following 

 table is extracted : — 



Chalk Marl. 



Parallel layers of a soft rock, " hassock," which rapidly ft. in. 

 disintegrates by exposure ; and of hard cherty sand- 

 stone, which, after weathering, stands out in high 

 relief - - . - - -37 



Sand, with beds of stone and chert - - -67 



Upper 

 Green 

 Sand. 



Gault. 



Lower 



Green 



Sand. 



Light-coloured gault, becoming gradually bluer 

 Beds of decided blue colour. No fossils have 

 found, except in the very lowest beds 



been 



Lower green sand. No notice required 



Bed containing oysters and Gryphoea - 



Various beds not noticed - 



A bed of argillaceous sand, containing large lenticular, 

 concretionary masses of very hard calcareous sand- 

 stone, locally termed " the crackers." These masses, 

 when broken, are found to contain numerous fossils - 



Blue argillaceous beds, the lowest of which approach 

 in their character to fullers-earth. The upper of these 

 beds contain Crustacea ; the lower contain remains 

 of Pinna. In the latter respect, these beds agree 

 with the clay that lies beneath the sand and stone at 

 Hythe in Kent, described in the paper read before the 

 Society in June last. If this bed be the equivalent 

 of the clay bed at Hythe, the crackers will represent 

 the stone- beds at Hythe, decribed in the same paper. 

 They also agree with the Hythe stone-beds, in being 

 very nearly at the same vertical distance above the 

 Wealden. For the purpose of comparison, the Hythe 

 section has been drawn to the same scale as that of 

 the Isle of Wight- - 



Atherfield rock, containing many fossils 



Dark greenish sandy clay, looking black when wet, 

 containing many of the same fossils as the rocky bed 



43 



103 



384 



21 



269 



Totals, 

 ft. in. 



104 



146 



15 



59 



2 2 



29 



- 752 i I 



