Mesozoic and Coenozoic Geology and Palceontology. 293 



stone on the top of the terrace; and at this place, the surfaces 200 feet 

 lower, and 100 feet higher, are scored in like manner. What agency 

 could produce this effect ? Here is an abrupt elevation of 100 feet 

 above the striated surface; and it seems hardly possible that an island 

 of ice, loaded with granite bowlders, could have stranded upon this pro- 

 jecting shelf, and produced the scoring, and that, at the same time, 

 others above and below could be made in like manner. 



The fourth district, in its greatest elevation of about 2,000 feet above 

 tide water, descends to the level of Lake Ontario, 240 feet above tide, 

 for the most part, in a series of steps or terraces over the successive 

 formations; the surfaces of these, from the highest to the lowest, are 

 grooved and striated, and in the limestones often beautifully polished. 

 There is no high land on the north, from which glaciers could origin- 

 ate to cover this entire surface. The relative levels, as well as the 

 directions of the water courses, must also have been different, to have 

 allowed of such effects from glaciers; for, under present circumstances, 

 we should hardh^ expect to find a glacier advancing from the vallej^ of 

 Lake Ontario, toward the southern margin of the State, and ascending 

 nearly 2,000 feet in 100 miles. Even admitting the glacial theory to 

 be true, it is probable that the glaciers would originate among the 

 mountains of Canada, or farther north among the primary rocks; and 

 in this event, we might expect to meet, intermingled with the earliest 

 drift, a considerable proportion of granite and other pebbles and 

 bowlders of the older rocks, which is not the case. 



There is another fact worthy of notice. The vertical faces of joints, 

 when much separated and nearly coinciding with the direction of these 

 grooves, are polished in the same manner as the surfaces. The chinks 

 and fissures, in the harder rocks along the sea shore, are polished, in 

 like manner, by the washing in of sand and pebbles b}^ the advancing 

 and retiring waves. 



The first plateau above Lake Ontario is often plentifully- covered 

 with bowlders. These usuall}' lie upon the surface, and alwa3\s upon 

 the top of the drift. They are not evenly distributed, but often appear 

 in immense numbers, scattered over several acres; while beyond this, 

 for a great distance, few are to be found. There appears to be no law 

 regulating their distribution, though they are more abundant in the 

 eastern than in the western part of the district. The bowlders are 

 often in immense numbers on the low ground just north of the Ridge 

 road from Wayne county to the Niagara river, and appear as if they 

 had been brought there while the water was limited by this barrier, 



