Yorkshire Naturalists at Malton. 233 
filacier dammed up the waters of the Calder and Colne at 
Horbury, and formed the large lake Calderdale. The Hudders- 
geld deposits could be satisfactorily explained as lake deposits, 
and this theory would also account for the high level gravels 
in the neighbourhood. The paper was illustrated by photo- 
graphs of the sections exposed, and by a map showing the 
extent of the lake. 
His second lecture dealt with the vegetation of the Vale 
of Pickering. After paying a high tribute to Mr. J. G. Baker’s 
‘Flora of North Yorkshire,’ he described the geology of the 
neighbourhood, tracing the beds of the Upper, Middle and 
Lower Oolites and their influence on the topography. The 
surface deposits were illustrated by Prof. Kendall’s Glacial 
Map of Cleveland, and on this basis he explained first the 
types of woodland occupying the calcareous dales on the north 
of the Vale, and distribution of the Pine in the higher parts. 
The woods of the Howardian Hills were described, and the 
distribution of the Beech was considered, and the influence of 
limestone on plant distribution, especially on the heather and 
grass moors in the district. The Vale itself was finally described, 
and the distribution of the vegetation shown in detail on a 
number of six inch maps, special reference being made to the 
marshy pastures and their economic influence, and the way in 
which its special topography has influenced man’s operations 
from earliest times to the present day.—W. E. L. W. 
GEOoLoGY.—Miss M. A. Johnstone, B.Sc., writes :— 
In solid geology, the only work done was at the exposures 
of Oolitic limestone. Several of the quarries mentioned by 
Mr. Burton in the circular notes were visited and typical fossils 
were collected from them. 
The glacial problems of the district and the solutions 
provided for them by the reseaches of Professor Kendall and 
others raised much interest in all sections of the society. 
From the higher levels near Malton, the eye could range over 
the wide vale of Pickering with its encircling hills, within 
which at one stage in the glacial epoch was penned up the 
whole or nearly the whole drainage of Southern Cleveland and 
the northern slopes of the Howardian Hills. Nearly due 
north of Malton, the torrents from the Lakes of Eskdale poured 
out of Newton Dale. Forge Valley brought the waters of 
another chain of lakes and every other dale added its minor 
flood from the moors. The waters of this great lake, surging 
to higher levels at times of melting snow and ice, hemmed in 
from the sea on the East by moraine and ice, converged towards 
the angle in the hills near Malton and cut a way down through 
the watershed of the Howardian hills, to escape into the Vale of 
York. This gorge, one of Professor Kendall’s ‘direct overflows,’ 
was visited, and its impressive and convincing outlines noted. 
1916 July 1. 
