/ in NortJi- Eastern America. 



9 



they form, afford the illustration to which I am desirous of 

 drawing the attention of my readers. 



No. 1, the Medina Sandstone^ consists of layers of brownisli 

 or red sandstone, intermixed with layers of reddish shaly or 

 shivery clay. These yield the red soils of the low flat belt which 

 skirts the southern shore of Lake Ontario. At its eastern ex- 

 tremity this rock contains few partings of clay, and produces 

 therefore poor sandy soils of comparatively little value. Over 

 much of these poor sands natural pine forests still extend, as the 

 traveller sees when he steams along the Lake from Rochester to 

 Oswego. But, as is occasionally the case with other sandstones, 

 the partings of clay increase in number and thickness towards 

 the west, producing first sandy loams, and finally rich clay loams 

 well adapted to the growth of wheat. Hence this same forma- 

 tion, which at the east end of the Lake affords only poor hungry 

 soils, yields between the mouths of the Genessee and the Niagara 

 rivers some of the richest wheat-lands in the State. 



No. 2, the Clinton Groujo^ forms a very narrow zone, which is 

 nearly concealed by the debris of the rocks which lie immedi- 

 ately above and below it. This group consists of green and blue 

 shales with limestone intermingled, altogether from 60 to 80 feet 

 in thickness. They are soft and thin, and have therefore been 

 washed away by the ancient sea nearly to the edge of the hard 

 thick limestone of No. 3 which lies above it. The admixture of 

 the fragments of this Clinton formation has produced a surface of 

 excellent wheat-soil. It forms a very narrow terrace of calcareous 

 clay, sloping with a gentle inclination towards the lake. The 

 dotted line N S in the map represents the line of the cross-section 

 (No. in.) given in page 18. A glance at the map will show 

 that along the line of this section the zone of the Clinton group is 

 broader than it is anywhere towards the west, reaches a breadth 

 in fact about equal to that of the Medina sandstone below, or of 

 the Niagara limestone above it. It is necessary to notice this 

 fact, otherwise this cross section would appear to be inconsistent 

 with the general indications of the map, in Avhich the Clinton 

 group forms usually a very narrow strip indeed. 



No. 3, the Niagara Group, consists of an enormous thickness 

 of limestone above, resting upon a great thickness of dark blue 

 crumbling shales below. At Niagara, where the river falls, the 

 limestone has a thickness of 130, and the shale of about 80 feet. 

 The shale alone, where it comes to day, produces stiff blue clays, 

 which, from the sloping nature of the surface, are generally dry 

 and susceptible of culture. Like many of our own still un- 

 touched clays at home, however, they are to be hereafter ren- 

 dered greatly more valuable by the introduction of our British 

 system of thorough drainage. This mode of improvement is 



