EXCAVATIONS AT EAST AND WEST AYTON. 
87 
The pipes turn southward from the high road, and run down 
the road to the station, the trenches being cut in a deep loamy 
soil up to the railway line. Beyond this they passed through a 
coarse ground which did not vary much till it approached the 
river, where the gravel died out into pure sand. A great 
number of boulders were turned up weighing a few stone 
apiece. I remarked only one boulder bigger than a man could 
carry, and it was of whinstone. 
The pipes also pass down the street of West Ayton past the 
Post Oiiice. I was unable to see the trench, but there was 
sufficient evidence to show the ground was of a gravely nature. 
An old footpath lay at a depth of almost a foot below the 
present one. 
Subsequently the water has been conveyed from Lonsdale 
Farm across the fields to Betton Farm—a distance of about 
half a mile. The coralline rock was found close under the 
top spit all the way. I expected this, as I had been told that 
the plough sometimes struck the rock, so shallow is the soil. 
None of the boulders turned up show any signs of ice polish 
or ice scratches, and in this respect present a great contrast 
with those found in their boulder clay of the coast. Attrition 
in water has doubtless rubbed off all ice marks. 
1 hese works indicate then four periods in the development 
of the district. 
1. A Picture of the Oolitic Age. 
Coral reefs are forming in a warm sea. Huge Phasianellm 
and elegant Delphinulas crawl upon the rocks ; Oysters and 
Pectens and Limas form beds ; now and again a big Ammonite 
drifts by. Exquisitely beautiful sea-urchins abound, and the 
pools are enlivened by fishes and crustaceans. The trench in 
Castlegate indicates this period. 
2. A Picture of the Great Ice Age. Millions of years have 
gone by. 1 he chalk has been formed at the bottom of the sea 
and raised into the wolds. I he tertiary period has come and 
gone, and left no trace. Then the temperature lowers, and 
eventually a huge glacier towering to the height of 400 feet 
pushes in between the chalk wolds and the oolitic hills, driving 
back the drainage of the district, and compelling it to force 
