GLACIAL BOULDERS IN CALDERDALE. 
JAMES SPENCER, 
Halifax ; Member of the Yorkshire Boulder Committee. 
GEoLocisrs tell us that the Glacial epoch was ushered in bya period 
of gradually increasing cold, which ultimately became so intense 
that the mountainous districts of Norway, Scotland, and the north of 
England became enveloped in a thick mantle of snow and ice. 
Then glaciers began to form on the mountains and upland valleys, 
from whence they radiated in all directions, but as soon as local 
obstacles were surmounted they all took a southward direction down 
the country and finally became confluent, forming one vast sheet of 
ice which covered Scotland and the north of England, and filled up 
the beds of the North and the Irish Seas with a vast thickness of ice. 
The route taken by many of these glaciers can be traced by the 
boulders which they dropped while on their way down the country. 
The glacier which brought down the boulders of granite, syenite, 
trap and volcanic ashes, etc., that now occupy so many miles ot 
the bed of the Calder appears to have originated in the Galloway 
Mountains (south-western corner of Scotland). Starting from the 
neighbourhood of the Solway, with its burden of ‘ Criffel’ granite 
boulders it came down the western coast* bounded on the west by 
the great glacier from the north, which occupied the bed of what is 
now the Irish Sea, and on the east by the land. It then spread over 
Morecambe Bay, where it was joined by a great glacier from the 
western side of the Lake District, bringing with it a vast quantity of 
Lake District rocks, including Eskdale granite, Ennerdale granophyre, 
quartz felsite from St. John’s Vale, Borrodale ashes, and many other 
characteristic rocks from that district. 
€ now greatly augmented glacier still kept to the western coast 
until it reached the neighbourhood of Blackpool and Lytham, where, 
probably meeting with less resistance from the land ice and being 
impelled by the great glacier on the west, it was forced across the 
Plain of North Lancashire, engulfing and overtopping hills of from 
* Criffel ’ granite from west to the east. e thi 
granite has been recognised, both in Lancashire and Calderdale. 
March 1893. 
