DAVIS : SECTIONS IN THE LIASSLC AND OOLITIC ROCKS OF YORKSHIRE. 197 
aud extends to Staintondale and Cloughton ; at the latter place it is 
quarried for building purposes. It forms the summit of the exten- 
sive Fylingdales Moor, dipping southwards under the Cornbrash and 
Kelloway's Rock of Hackness, Wykehain, and Pickering Moors. 
In this district the Lower Oolites are principally of estuarine 
formation ; in the South of England they are exclusively marine. It 
is evident that whilst in the Oolitic areas of the Middle and South 
of England the strata were deposited under marine conditions, at the 
same time in the north for a long period there were alternations of 
marine, estuarine and terrestrial conditions. I he thin bands of the 
Millepore and Scarborough Limestones being deposited in the sea. 
The beds of coal and leaf beds of the middle estuarines indicating 
a terrestrial surface. 
II. The Gristhorpe and Filey Sections. 
The Lower Oolites have been traced from their junction with 
the Liassic Beds at the foot of Peak to the summit of the escarpment 
at Blea Wyke, and this incomparably fine section comprises all the 
series from the Dogger's to the Upper Estuarine sandstones and 
shales. To continue the series a profitable and most interesting 
series of sections are exposed on the coast between Scarborough and 
Filey. At Gristhorpe, midway between the two, the cliffs and 
scars exhibit the rocks between the Estuarine Series and the Lower 
Calcareous Grit. The lowest rocks are part of the Lower Estuarine 
Series, and consist of irregular but massive sandstones ; they form 
the lowest part of the scars or reefs opposite Yons Nab, the northern 
extremity of Gristhorpe Bay. They appear to have become much 
harder than at Peak ; they are only exposed at very low water. 
Above these sandstones the Millepore Beds form a reef of rocks 
extending from Yons Nab south-eastwards completely across the 
bay to the Old Horseshoe Rocks. The beds are composed of a very 
hard siliceous calcareous sandstone with ferruginous partings. It is 
false-bedded and full of the remains of crinoids, and has every ap- 
pearance of having beon deposited during a slight subsidence of the 
estuarine beds beneath the sea, in shallow water. The true Mille- 
pore beds are about 15 feet in thickness. Resting on them at Yons 
Nab are 25 feet of strata, which from the contained fossils are evi- 
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