162 HELDERBERG DIVISION. 



bj a ilun band of Oriakany sandstone. The bed usually quarried for cement, is not no- 

 ticed ; though at Vienna in Ontario county, it is two feet thick ; and in Genesee county, 

 al Morganville, the waterlime is thirty-eight feel thick, consisting of four feet in thin 

 courses, twenty-two feet in thick courses (in combination with silcx) , and twelve feet in 



graj layers « ah scams of blue marl. The scries terminates below in the screen and grayish 

 fragile shales or marls. 



I'lu- development of the upper part of the series I have been describing, is best in Scho- 

 harie county, while the lower part is best exposed in Onondaga county. At Schoharie 

 village, the following series occurs at the strontian locality, on the slope west of tin* creek : 

 1, Hudson-river series, three hundred feet exposed ; -\ Waterlime series of the Onondaga- 

 salt group, consisting of blue thick-bedded limestone, and greenish or drab-colored shaly 

 limestone, one hundred feet, and pentamerus, twenty feet. Between the Hudson-rivet 

 series and the waterlimes, the red shales are feebly developed, and contain, as at the Kon- 

 doul falls, numerous crystals of sulphuret of iron. Developed also in and beneath the mass 

 of thin-bedded limestone containing strontian and barytes, is a mass of compact blue lime- 

 stone about eight feet thick, in which favosites abound, and which is scarcely known out 

 of Schoharie county. 



Soils of the Onondaga-salt group. The debris of the rocks of this group is almost uni- 

 formly of a drab color, and it may be usually traced to the source from which it is derived. 

 It becomes line by the slow process of disintegration ; constantly furnishing-, in the changes 

 it undergoes, suitable materials for vegetable food. The soil, as might be expected from 

 the character of the rock, is excellent : it possesses a sufficient tenacity for the growth of 

 wheat ; but sometimes, especially where the clay predominates, it acquires too much tena- 

 city for indian corn. The clay beds possess the same colors as the soil, only they are of 

 deeper tint. 



It will be noticed, from the preceding description of the localities where these rocks are 

 developed, that the lower parts of the group furnish the best soil, as they undergo more 

 rapid decomposition. The process is slow in the superior portion of the waterlimes, still 

 the soil furnished in each case has the same general character ; but in consequence of the 

 great development of the lower portion in the central part of the State, the soils are 

 much more widely spread anil extended than to the eastward : it is, moreover, derived 

 from the rocks themselves, and without intermixture to any considerable amount of the 

 northern drift. 



The soil and clay of this series may generally be distinguished from that of the slates of 

 the Hudson-river series : the latter is bluish, and rarely of that distinct drab-color possessed 

 by those derived from the waterlimes, although it is true that the upper clay of the Hud- 

 son river series is of a drab or yellowish brown color. As I propose to treat of the soils 

 of the different rocks under a separate head, I leave this subject at present. 



Sj/iings and wells whose origin can be traced to Hie Onondaga-salt group. Probably no 

 series of rocks furnish such a variety of soluble products as the Onondaga-salt group ; and 



