PROCEEDINGS OF GEOLOGICAL SOCIETIES. 



261 



Laurcutine chain of mountains, on the north side of the St. Lawrence, which for 

 an extent of 1,500 miles exhibit, often in spite of the forest, unequivocal signs 

 of glacial abrasion, being mammillated (or moutonnces), as if by the action of 

 ice. 



On the soiith side of the river, the country is low, and covered with boulder 

 and other drifts, derived from the Laurentine Chain and other tracts, in accord- 

 ance with the observations of Bigsby, Hitchcoclv, and others. The plains and 

 the Thousand Islands exhibit a general glacialization. These conditions are 

 traceable down the Valley of the Hudson to New York . 



During the period when the boulders and the associated clays and gravels were 

 being deposited, the Catskill Mountains appear to have been under water, and at about 

 the same period to have been subjected also to very extensive glacial action. The 

 strife left by ice-borne rocks on the eastern flank of the Catskills have a noi-th and 

 south direction, and are found up to nearly the height of 3,000 feet above the sea, 

 excepting in the east and west gorges near the top, Avhere the stria? rmi m a 

 cross direction — E. and W. The sea of the drift-period in the Valley of the Hudson 

 was then from 3,000 to 4,000 feet dee]). The deep valleys on the western side of 

 the mountains were observed by Prof. Ramsay to be often charged with drift, 

 Avhich had not been ploughed out by glaciers of a date subsequent to the upheaval 

 of the Catskills, as is the case with some of the valleys, once occupied by drift and 

 afterwards by glaciers, in Wales, the Highlands, the Vosges, and in the Alps. 



Prof. Pamsay then referred more i):iriicul;ivly to the di-ift-deposits forming 

 terraces in the neighbourhood of iSrontrcal, v/liidi bin e lately been described in 

 detail by Dr. Dawson; and ]i()inte(l out his rr;<sons t'ov regarding the JiCda-clay of 

 Dawson to be of contemporaneous foriniition \\\\]\ the Xucula-clay of the 

 eastern side of Lake Chamjilain, and with tlio clay-bLHls of Albany and elsewhere 

 on the Hudson. The cl.iy of the Hudson A'alley lies on bonlder-l)e(ls, and rarely 

 contains boulders. Along Lake Chaniplain similar clays overlie old drift, at 

 about 150 feet above the sea-le\el, au'l contain fossils similar to those of the 

 Montreal clays, at 110 feet above Ib.e sea, and (;f other contemporaneous beds on 

 the Ottawa. Prof. I\amsay assumed Dr. Dawson's coni-lusion as to the age of 

 the Leda-beds, which were deposited, in a thickness of from 100 to 300 feet, over 

 the boulder-clay, whilst the sea covered the Ontario basin, and came up against 

 the great escarpment of Niagara limestone, which, now stretching across this 

 region, formed the southern coast of the glacial sea. 



The author then inferred that, the Erie plateau having been elevated, the falls 

 of Niagara commenced, by the drainage of the upper lake-area, a little before the 

 close of the drift-jJcriocl, falling first into the sea over the edge of the escarpment 

 above Queenstown and Lewisto\ATi. If the 35,000 years suggested by Sir C. Lyell 

 as the minimum for the time occupied in the erosion of the gorge of Niagara be 

 approximately correct, though probably below the reality, we have an idea of the 

 amount of time that has elapsed since the close of the drift period. And, if it 

 be ever found possible to accurately determine the ancient rate of recession, we 

 shall have data for a first approach to an actual measurement of a portion of 

 geological time. This subject is intimately connected with the synchronism of 

 the mastodon-bearing iVeshwater strata of Niagara and those of the bluft's of the 

 Mississippi^ 



2. "On Lamination and Sleavage occasioned by the mutual friction of the 

 particles of rocks while in irregular motion." By 0. Poulett Scrope, Esq., M.P., 

 E.P.S., F.Ct.S. 



The author referred to a former paper read by him before the Society in April, 

 1856, in Avhich this subject was touched upon, and proposed to carry on the 

 inquiry as to the probable effect upon the internal structure of rocks, of the 

 mutual friction of their component parts when forced into motion under extreme 

 and irregular pressures. He commenced by examining the laws that determine the 

 internal motions of substances possessing a more or less imperfect liquidity, 

 whether homogeneous, or consisting of solid particles suspended in, or mixed with, 

 or lubricated by, any liquid, under unequal pressures ; and showed that unequal 

 rates of motion must result in the different parts of the substance, and that in 



