418 
EXCURSIONS. 
was reached. Interest here was divided between the limestone 
beds of the quarrj^ and the remarkably fine exposures of the 
Boulder Clay which was being removed in order to enable the 
quarrying operations to be extended. 
The limestone itself was simply one mass of broken stems 
of encrinites, which must have flourished abundantly in the 
carboniferous sea of this area. 
In places the entire quarry face could be seen to be formed 
by the interlaced stems beautifully weathered out. There was 
just a question as to whether it was the Underset or Main lime- 
stone, but the evidence, such as it was, rather strengthened the 
view — commonly held — that it is the Underset. This is just one 
of the points where, in the present state of knowledge, the fossil 
evidence is not sufficient to enable the distinction to be made. 
The chief point of interest, perhaps, was the beautifully 
polished and scratched upper surface of the limestone from 
which the Boulder Clay was being removed. The management 
had thoughtfully washed one portion where the groovings were 
very distinct. Nothing clearer in the way of evidence as to 
the direction of movement of the great glacier could be wished. 
It might, too, have caused the suggested diversion of the Tees, 
but while the members were quite willing to accept the glacier and 
its movements, the river diversion theory was held over for con- 
sideration until the leaders of the excursion had an opportunity^ 
of bringing forward more convincing evidence, than had been seen 
during the morning. After enjoying the hospitality of the pro- 
prietors of the quarry, the members drove through Aldbrough, 
with its spacious village green and interesting old houses. 
A halt was called at the Forcett Quarry where lunch had 
been provided by the proprietors. Under the guidance of 
Mr. Abbott, the manager, the drift covering of the quarry and 
the uncovered pre-glacial floor with its clints and potholes were 
inspected. This old pre-glacial floor must have rather resembled 
the well-known surface of the Great Scar Limestone of Ingle- 
borough. In the face of the quarry could be seen the ancient 
potholes that had been filled with drift w^hen the glaciers of the 
Ice Age moved slowly over the land and obliterated many of 
its ancient features. 
