HAMSTEAD BEDS. 201 



correspond with those on the Signal Hill (B.H. 11). It is there- 

 fore not improbable that an outlier of the marine beds may be 

 found higher up near the Farm, where the land is 20 feet higher. 

 But the exact position of the synclinal axis has not been fixed ; 

 if it lies south of this boring the ridge will be a dip slope and 

 there will be no outlier. 



East of the Medina the beds continue with the same character, 

 except that in the middle portion is developed a bed of sand. 

 Tracing first the lower beds, we made a series of borings (B.H. 

 1 to 9) between Newport and Whippingham. These show that 

 the strata on opposite sides of Medina exactly correspond, and that 

 there can be no fault down the valley. The Nematura beds are 

 found opposite the Cement "Works at exactly the same level as at 

 the Works. Lower down the river the Black Band occurs. There 

 is no necessity to repeat the details of the borings. 



At Whippingham the Black Band rises quickly, so that it must 

 cross the 100-foot contour near the village. A short distance 

 further north characteristic fossils of the Nematura beds were 

 found by Dr. Wilkins in a well at the Keeper's Cottage at 

 Osborne.* From this point eastward the base of the Hamstead 

 beds cannot be traced till Palmer's Brook is passed. But between 

 the Brook and Palmer's Farm four borings (B.H. 175, 176, 177, 

 178) seemed to have been sunk in the lower part of the Ham- 

 stead Series, one of them reaching the Black Band. 



Half a mile to the south-west Alverstone Brick and Tile Works 

 deserve notice as one of the few localities where the Hamstead 

 Beds can be examined in an open section. The strata there 

 visible belong perhaps to that part of the series which overlies the 

 Nematura beds, but the fossils are not sufficient to settle this 

 point, though a boring was carried 17 feet below the bottom of 

 the pit. The following is the section obtained : — 



Alverstone Brick Yard. 



Feet. 



Blue and yellow claj'-, with a thin seam of shelly marl. Paludina 

 angulosu, Hydrobia Ghasteli, Melania muricata, M. Forbesii, 

 Melanopsis subulata, Fish bones, and Folliculites thalictroides 6 



Ferruginous clay and ironstone ----- a 



Laminated clay, with sand partings. Folliculites thalictroides, 

 Sequoia, and other plant remains, Trionyx ? - - - 5 



Blue and yellow laminated clay, with selenite, becoming stifBer 

 below. Paludina and Melanopsis carinata at 20 feet from 

 surface - - - - - . -17 



28f 



The whole of the beds, except those reached in the lower part 

 of the boring, are much weathered. Then the Black Band is again 

 lost, though wells show that the Lower Hamstead beds are well 



* On a newly-discovered Outlier of the Hamstead Strata, on the Osborne 

 Estate, Isle of Wight. Proc. Geol. Assoc, vol. 1, p. 194. (!8f51.) 



