LOWER LIAS : SOUTHERNPOWN. 
105 
down, for the beds may be traced eastwards continuously, past 
Southerndown beach to the cliff by the fault west of Dunraven 
Castle. That in this division of the cliffs the sequence is clear, 
may be proved by detailed measurements of the beds at either 
end of the beach ; and by observing the continuity of a thick and 
prominent band of limestones (with little shale), that occurs near 
the upper part of the Southerndown cliff and appears again on 
the Dunraven side of the little bay. (See Fig. 45.) 
In the entire section, about 180 feet of ordinary Lower Lias 
limestones and shales have been exposed, and of these beds about 
100 feet are shown in the Southerndown cliff. These beds rest 
on a series of hard and more massive beds of bluish conglomeratic 
limestone and shale (Southerndown Series) that form the base of 
the cliffs ; and, as the strata undulate, the sequence can be traced 
upwards from the lowest bed exposed on the foreshore at the 
western end of the bluff, and again further eastwards, whore the 
ledges and platforms of rock stretch out seawards for some distance. 
Unfortunately in these exposure^ we do not find evidence of the 
white Sutton Stone and conglomerate anywhere along the base 
of the cliffs or foreshore. Brislow's section vras evidently taken 
from this portion of the cliffs, and consequently it did not show 
the Sutton Stone that underlies the Southerndown Beds. He 
notes the occurrence of an irregular layer of black chert, in 
addition to the derived fragments of this rock ; and Conybeare 
noted that specimens of Grypho^a, coated with chalcedony, were to 
be found in the Lias of this area.' 55 ' In order to make clear the 
sequenca we must carry our investigations further eastwards 
beyond the Witches Point. 
The section of the beds at Southerndown, traced westwards 
from the fault seen in the cliffs east of Southerndown beach, and 
near Dunraven Castle, is as follows: 
FT. IN. 
Limestones and shales (mostly inaccessible). 
Unicardium cardioides and Gryphcea 
arcuata in lower beds - - About lUO 
Thick and prominent mass of irregular lime- 
stones and marly clays ... 
Alternate bands of earthy, compact, and 
shelly limestone, and dark shale : yielding 
Ammonites Bucklandi, Gryphcea arcuata, 
Ostrea, Unicardium, lignite 
(Hard grey and conglomeratic limestones with 
thin shaly beds. Gasteropods abundant 
in different layers of limestone. Cerithium, 
Litlorina, G. arcuata 
Hard grey limestones, conglomeratic, and 
with obscure shaly layers. Ammonites, 
lignite - ... 
Hard blue and grey limestones, with occa- 
sional conglomeratic beds, cherty lime- 
stone, and indurated shale 
Hard blue limestone, with chert fragments ; 
Gasteropods 
Hard blue conglomeratic limestones, with 
indurated shaly bands. Seen to depth of 
Zone of 
Ammonites 
Bucklandi, 
Southerndown 
Beds. 
- 10 
65 (I 
5 6 
4 3 
24 3 
1 
13 
* Conybeare and Phillips, Geol. Eng. and Wales, p. 2C5 ; see also J. J. Conybeare, 
An. Phil., 1822, p. 336. 
