40 Geological Reports on the State of Neio York. 



only are perceived, while in others they are numerous and deep, often ex- 

 tending for several feet, and in one case a continuous furrovs? was observed 

 one hundred feet in length. The general direction of these scratches is 

 N. N. E. and S. S. W. ; sometimes there are slight variations from this 

 course. The appearance of the scratches often indicates that they were 

 produced by two boulders coming in contact, when the lighter one was 

 moved out of its course, producing a furrow in the direction of the force 

 applied. 



" Where the soil is removed from the polished and furrowed rock, we 

 find resting upon it, in many places, an irregular deposit of pebbles and. 

 boulders, some of the latter of large size. These are frequently cemented 

 by a gravel or hard pan, with infiltrated carbonate of lime. Above this 

 stratum we have clay, sand, and loam, with little or no coarse materials. 

 These boulders are of various granites, limestone from the formation on 

 which they rest and from the south, and siliceous sandstone from the 

 north. These materials all attest the action of violent currents, and not 

 of a single and uniform current, but of opposite or conflicting ones. The 

 presence, in the same locality, of boulders from the north, with those from 

 the south, proves that opposite forces have prevailed either at the same or 

 at different periods. 



" The extent of these diluvial formations, with the great numbers of 

 erratic blocks, and the evidence of long continued wearing action on the 

 limestone, proves that the force was not sudden and violent, but contin- 

 ued for an indefinite period. If then, we admit the presence of an ocean 

 covering the continent or a part of it, we should also admit the condition 

 of an ocean as we find it at the present time." 



" Lake Ridge. — Ridge Roads. — One of the most remarkable features 

 of the surface of the Fourth District is the ' Lake Ridge,' which is a 

 travelled highway from Sodus, in Wayne county, with some slight inter- 

 ruptions, to the Niagara river. West of the Niagara river, we find a con- 

 tinuance of this ridge, and it probably passes around the head of Lake 

 Ontario. Throughout the greater part of this distance, the ridge is well 

 defined, being a slight but actual elevation above the general surface of 

 the country. In some places, the descent is abrupt on either side of the 

 ridge, but in general, it is gradual. The elevation of this ridge above 

 Lake Ontario is, in Niagara county, about one hundred and sixty feet, 

 though there are variations of a few feet. The course of the road along 

 the ridge should not be taken as a guide for its elevation, as in some cases 

 the road passes over the point of a hill which projected into the ancient 

 lake, and at which place the ridge is not so well defined. In other cases, 

 the ridge has been partially removed by streams, as a beach now is form- 

 ing along the lake shore. We often find this ridge divided into three or 

 four parallel ones, which extend for a few rods and then unite in one. 



