and Geology of Lake Ontario. 343 



lities I have seen two or three beds in succession alternating 

 with layers of the sand rock ; rarely with those of the slate 

 rock. The best ore beds (or perhaps, more properly, the 

 best parts of the great stratum of argillaceous iron ore) which 

 are at present wrought are between Little Falls and Oneida 

 Creek on the south side of the canal, and between Lyons and 

 the Genesee River on the north side." West of Genesee River, 

 the iron formation is chiefly on the south side of the canal as 

 far as Lockport*. 



Ferriferous Sand-rock is the other stratum, so characterized 

 by Mr. E., from its abounding in iron. He defines it to be " a 

 gray or yellowish gray massive aggregate of quartzose grains, 

 often hyaline, and without cement. 



This stratum is fourteen feet thick at the I'ivers Genesee and 

 Niagara; but at the out-croppings of these two rocks near the 

 Mohawk, and wherever their full thickness is in view, almost 

 to Vernon, the sand-rock is five to ten times the thickness of 

 the slate. This rock is hard, breaking into thick shapeless or 

 square-faced blocks. In some places the two rocks alternate 

 with each other, but generally they are separated by a con- 

 tinuous layer, or extensive bed of argillaceous iron ore. " — 

 (P. 120.) 



" The ore embraced in this rock is more granulated, and 

 has less the appearance of the lenticular form than that which 

 is between it and the slate, or embraced in the slate. More 

 of the jaspery variety is found in it ; and sometimes the oxide 

 of iron is in larger proportion, compared with the alumine, 

 than is found in connection with the ferriferous slate-rock." 



Calciferous Slate of Eaton next follows. It is " an aggre- 

 gate of quartzose sand and clay-slate, or other aluminous com- 

 pounds. Sometimes it is a soft thin slate ; but it is often hard, 

 siliceous, and rings more or less on being struck. It is of a 

 gray colour, and can scarcely be distinguished from grauwacke 

 slate in hand specimens with the naked eye. But under the 

 magnifier the constituent particles appear somewhat rounded ; 

 and it is nearly or quite destitute of the shining scales." — 

 (G. S. p. 37). 



This position of this rock is seen very clearly in numberless 

 places, and throughout the whole district now under discus- 



* " In the liottoiu of a well in Salina, at the upper part of the village, forty- 

 three feet deep, this rock presents a very singular structure. The surfaces 

 of the layers, which are about half an inch thick, arc marked with angular 

 grooves, so arranged as to resemble the mid-ribs of leaves, with lateral se- 

 condary ribs and veins. These appearances are undoubtedly the effect of 

 a crystalline tendency. They may be compared with the crystals of frost 

 on a glass window." — G. S. p. 1 1!). 



sion. 



