THE HAMILTON ASSOCIATION. 25 



pavement are more clayey than sandy, while to the north the sand 

 predominates over the clay. The percentage of boulders is in 

 many localities greatly Laurentian, Huronian and Montalban ; in 

 others the Hudson River calcareous sandstones predominate, and 

 few, if any, Medina pebbles and boulders are found. It may be 

 added that the boulders are well rounded and as a rule free from 

 ice-marks. 



About half a mile to the south lies the famous Second Terrace, 

 the ancient lake margin, of which Burlington Heights is the contin- 

 uation. This beach, as has been shewn by other observers, enters 

 the Province at Queenston Heights, follows the escarpment to 

 Hamilton, forms there the Burlington Heights, and runs on across 

 the Counties of Wentworth, Halton, Peel, York, Ontario, Northum- 

 berland and West Hastings. While in the last locality the ridge 

 rises to the height of over four hundred feet, at Beamsville the 

 average elevation is about sixty feet, or about a hundred and ten 

 feet above the present lake level. It is composed of stratified 

 brown clay full of boulders in many places, the boulders being of 

 the same character as those of the boulder pavement. Strange to 

 say, however, here and there, especially on the Thirty Mile Creek, the 

 terrace is composed of unaltered Medina deposits, the conditions 

 for excavation having been favorable and those for deposition the 

 reverse. 



But this second terrace slopes gradually southward and upward 

 to a third beach, which abuts against the lower Niagara escarpment ; 

 here and there it rises suddenly, but in general its slope is gradual, 

 with billowy, sweeping outlines. While here and there in the val- 

 leys of the creeks which cut into the deposits, the Medina series, 

 grey band at the top and all, may be seen, the material of this beach 

 seems to be in general a lighter brown clay, here and there contain- 

 ing boulders and pebbles, principally Archaean or Hudson River in ' 

 age. 



The fourth beach is, as has been said, the lower escarpment, 

 the Pentamerous limestone, at the base of the Niagara series. Very 

 often the beach is semi-circular in form, as may be seen near Beams- 

 ville, near Grimsby, and near Stony Creek. It may show upon unex- 

 posed surfaces deposits of clay and sand, but as a rule these are ab- 

 sent, for a reason suggested above. On exposed surfaces, however, 

 ice-marks and grooves are plentiful, and seem to be due to coast-ice 



