176 DAVIS: SECTIONS IN THE LIASSIC AND OOLITIC ROCKS OF YORKSHIRE. 
thrown down to the foot of the cliff and the scars at Peak Steel. 
It is proposed to give a description of the several beds, which are 
admirably exposed for observation, perhaps nowhere elso so well, in 
Robin Hood's Bay and Peak. 
FIG. 3. — SHORE-PLAN IN ROBIN HOOD'S BAY, SHOWING THE POSITION 
OF THE LIAS-ZONES. 
The Lower Lias is more extensively exposed in the scars and 
cliffs of Robin Hood's Bay than elsewhere in Yorkshire. The lowest 
beds containing Ammonites planorbis do not occur in Yorkshire, but, 
as Professor Blake has pointed out, it probably occurs in the bottom 
of the North Sea, because hard calcareous nodules are constantly being 
washed upon the shore, which contain that fossil in excellent preser- 
vation. The next zone, Am. angulatus, is exposed at Redcar, and 
the succeeding beds, in the district under consideration. The rocks 
here consist of argillaceous shales, slightly sandy and of a dark 
colour, with bands of hard marl in the lower part. The Lower Lias 
may be divided into the following beds, each characterized by a 
distinct fauna. 
' d. Soft shales with rows of ironstone 
doggers. 
B. Soft shales with rows (Zone of Am. Capricornus) Gryphwa 
of ironstone doggers J obliquata. 
and pyritous nodules, c. Soft shales with rows of pyritous 
320ft. nodules. 
(Zone of Am. Jamesoni) G. obliquata, 
\- Pinna folium. 
