162 JlgricuHitral Geology of Onondaga County. [April, 



soil in the county of Oswego, but in Niagara its inferior portions 

 ai'e soft and marly, and must have contributed largely to the 

 formation of tlie soil in the western and middle divisions of the 

 state. Still, in Onondaga county, its effects are manifested rather 

 in the furnishing an abundance of red or brown cobble stones, 

 than the fine materials of which the soil is composed. 



The Clinton group, which succeeds the Medina sandstones in 

 the ascending order, is a heterogeneous mass of rocks, some of 

 which are soft and shaly, and liable to disintegration; others are 

 hard and sandy, and resist the action of the weather with con- 

 siderable obstinacy. These, however, skirt the county only on 

 its northeastern bordere, passing through a portion of Lysander. 

 The same remark, in regard to the group, which has been made 

 of the Medina sandstone is true, that it has but little influence 

 upon the soil of this county. 



We now pass at once to the rocks of the county, and they 

 merit, from their influence upon the agricultural capabilities of 

 this part of New York, an extended description. We shall adopt 

 the same divisions of the formations as those which have been 

 given in the New York reports. 1. The red shale; 2. The 

 greenish shale with hopper-form cavities, plaster beds and vermi- 

 cular limestone layers; 3. The water limestone; 4. Onondaga 

 limestone; 5. Marcellus shales; 6. Hamilton group. 



1. Red shale. It is exceedingly soft throughout, except a few thin 

 strata of sandstone near the top: but even these fall to pieces, and 

 cannot be employed at all for purposes of construction. It is pro- 

 perly a red marl, and whenever it crops out, is generally covered 

 by its own debris. Its greatest thickness is about 500 feet, and 

 as it underlies the whole northern border of the county, it is agri- 

 culturally an important rock, and has contributed largely to the 

 formation of the soil. Its debris, as would be expected from the 

 nature of the rock, is argillaceous; but not excessively so. The 

 nature of the soil is better indicated, however, by the composition 

 of the rock itself: thus, the elements of one hundred grains of 

 the most sandy part, and the same amount of softer kinds, we 

 have found combined in the following proportions: 



