177 
GEOLOGICAL NOTES ON THE ROBIN 
HOOD’S BAY DISTRICT. 
Professor PERCY F. KENDALL, M.Sc., F.G.S. 
Tue Whitsuntide excursion of the Y.N.U. to Robin Hood’s Bay 
will afford the members of the Geological Section an opportunity, 
of which they will probably not be slow to avail themselves, of 
studying a series of rocks unsurpassed in Britain for the com- 
pleteness of their development and the excellence of the 
exposures, both on the coast and inland. The physical features 
are of equal interest to the stratigraphy, and the paleontology 
to both. But the geological fare is even more generous still, 
and students of geological tectonics and of glacial geology will 
find entrées as subtly compounded as the most fastidious palate 
could demand. The fzéce de resistance is, of course, the 
Jurassic series, and with Spring Tides (the moon is new on 
Whit Sunday) the magnificent exposures on the scars and in 
the cliffs will be easy of access. 
The whole Liassic succession can be made out in the Bay 
with the sole exception of the lowest Zone, that of Asmmonztes 
(Pstloceras) planorbis, and of that evidence is occasionally 
obtainable in blocks thrown up from submerged reefs. At 
Blea Wyke can be seen the only certain occurrence in Yorkshire 
of the Zone of Lytoceras jurense and of the overlying Blea Wyke 
Beds which form a complete passage from the Lias into the 
Inferior Oolite. These are succeeded by the most important 
development of the Dogger to be found in the country, and that 
is followed by the great Estuarine Series with its occasional 
marine beds, which have played an important part in the 
correlation of the Lower Oolites of Yorkshire with their south- 
country equivalents. 
All these Jurassic beds are well furnished with the fossils. 
characteristic of their age and of the conditions under which 
they were deposited. The principal problem which these rocks 
present is connected with the movements of a large fault 
which is exposed in the upper part of the cliff at Peak, and 
bifurcating seaward produced Peak Steel, a triangular reef of 
Middle Lias let in between the Lower Lias of Robin Hood’s 
Bay and the Upper Lias of the foreshore to the south of 
the point. 
1907 May 1. 
