GEOLOGY OF SARATOGA SPRINGS AND VICIxNITY II 



similar character. But unlike the shale belt of the Mohawk, these 

 shales are greatly deformed. They have been compressed, folded 

 and faulted, and show steep dips nearly everywhere, instead of 

 lying flat. The boundary between the two shale belts is fairly 

 abrupt, and is readily traced across the Saratoga di-strict. The 

 shales of the Saratoga quadrangle are the undisturbed shales of 

 the Mohawk belt, while the greater part of those of the Schuyler- 

 ville quadrangle are the tipped shales of the Hudson valley belt. 

 The greater part of the Schuylerville quadrangle is included in the 

 Hudson lowland. 



There are occasional harder bands in these tipped shales, bands 

 of hard sandstone or grit and chert, whose lines of outcrop form 

 low ridges on the otherwise level valley floor. Glacial deposits 

 also diversify it somewhat, as they do along the Mohawk. Close 

 to the river they have been washed away, but back from it they 

 rise in prominent benches and widely cover the valley floor so 

 that rock outcrops are very exceptional. 



Two hilly tracts of land rise from this plain, one east of Sara- 

 toga lake, culminating between Ketchums Corners and Quaker 

 Springs and attaining the 600 feet level ; the other in the northeast 

 corner of the Schuylerville sheet, north of the bend in the Moses 

 kill. A landmark in the broad plain north of Fish creek is Ken- 

 drick's hill rising 200 feet above the plain. 



The hilly region at the eastern edge of the Schuylerville sheet 

 is the western margin of a plateau of somewhat higher level. This 

 plateau is but little higher than the Hudson river plain ; its base 

 is about 400 feet above sea in the west and it rises gradually to 

 about 600 feet across the adjoining Cambridge sheet to the eastern 

 edge of that sheet, where another somewhat abrupt rise takes place 

 to a higher plateau. W'e will call this lower plateau, which is about 

 10 miles wide, the Greenwich i)lateau. It can be traced on the east 

 side of the Hudson across the Hoosic into Rensselaer count}' and 

 south, where it lies in front of the Rensselaer plateau and has 

 been fully described by Dale.^ This plateau is characterized by its 

 extremely irregular surface, as shown on the easterii edge of the 

 Schuylerville sheet. It is covered with a great number of more 

 or less oval hillocks, mostl\' but a few hundred feet high, but in 

 many cases rising 500 feet, and in some c\ en a thousand feet above 

 the plain. It gradually approaches the Hudson river until at Troy 



1 Dale. T. Nelson. (Jcolog}- of tlu- lludsoii \'allc> hot w ten tho lloosic atul 

 the KiiKk-rliook. U. S. (ie<il. .Surw I'ui. 242. i<X)4. 



