PHYSICAL AND CLIMATIC SETTING 23 



formations are of special importance because of their 

 bearing on the later introduction of lime into the 

 soils with its attendant agricultural significances. 

 Their position with reference to the topography of 

 the State and the important agricultural areas is 

 also important in the matter of supplying lime to 

 the soils that require it. 



The remainder of the State upward and south- 

 ward from the Helderberg limestone is a succes- 

 sion of shales and sandstones with occasional thin 

 layers of limestone. Their color varies widely, but is 

 predominantly gray or black. The first important 

 division of these is the Hamilton shale which is some- 

 what calcareous. But the great mass of these forma- 

 tions is very lean in lime content and weather down 

 to a light brown or yellow soil material. They be- 

 long to that part of the Devonian series usually 

 known as the Catskill group. Some layers are hard 

 sandstone, others soft shale. Capping the Catskills 

 is a rather hard layer of conglomerate rock, expressed 

 in the topography of the country as the protection of 

 hills and the facing of steep slopes and waterfalls. 

 Centering in Delaware County is an area of dark red 

 shale and sandstone known as the Oneonta forma- 

 tion which has a marked effect on the soils of the 

 region. 



The topography of this southern region is the ex- 

 pression of the resistance of these soft and hard rocks 

 to long erosion, coupled with the factor of elevation. 

 The Catskills are highest, have the hardest capping 

 and have been most eroded. Hence, it is a rough 



