APPENDIX. VI 



I saw no traces of any kind of organic remains in these lower 

 dark shales, excepting a few trails, apparently of annelids, but 

 they doubtless owe their dark color mainly to minutely com- 

 minuted particles of organic matter, perhaps chiefly of marine 

 plants. From their position, however, and general appearance, 

 there is little or no reason to doubt that they represent the Mar- 

 cellus shale of the New York series ; which, although sometimes 

 viewed as a distinct formation, may perhaps be properly con- 

 sidered a subdivision of the Hamilton group. Here these dark 

 beds are seen to shade upward into various lighter colored shales, 

 and flags, presenting different shades of drab, olive, and dull gray, 

 and bluish-gray. In some parts there are intercalated layers of 

 various thickness and harder texture, composed of variable pro- 

 portions of arenaceous and argillaceous matter. These latter 

 harder layers are usually of dull gray coloi', or often on fresh 

 fractures, bluish-gray, and, as may be seen in other cuts further 

 eastward and westward, increase in proportion to the more shaly 

 portions as we ascend in the series. At some places, however, 

 higher in the series there are seen beds of dark shale. The lighter 

 colored shaly beds above the lower dark shales are often quite 

 soft, and are dug out along the railroad in small rhomboid blocks 

 that soon crumble under exposure to atmospheric agencies. 



Fossils seem also to be rather rare here in the lighter colored 

 beds of the Hamilton group, near the bases of the mountains, in 

 the immediate vicinity of the springs, but I succeeded in finding, 

 in some of the harder layers at several places along the cuts of 

 the railroad, and up the side of the mountain to the southeastward, 

 casts and moulds of the well-known Hamilton species, Spirifer 

 mucronatus, and Orthis Vanuxemii, along with Martinia umbo- 

 nata, Atrypa reticularis, A. aspera, a flattened Strophomena and 

 a smooth Avicula or Pterinea. 



From what has already been said, it seems that there are here 

 no representatives of the Upper Helderberg limestones or grits 

 of the New York series ; the black shales at the base of the 

 Hamilton group being found resting directly against and upon 

 the Oriskany. 



West of the Springs, the lower dark shales are seen along the 

 base of the mountains for a mile or more, on the right or north- 

 west side of the valley, dipping at high angles to the northwest- 

 ward, or at places locally tilted vertically, or variously flexed and 

 distorted as if by lateral pressure, as well as from upheaval. 

 The direction of the valley here is southwestward, but within a 

 short distance its direction becomes nearly east and west, and five 

 miles below, it curves around more nearly to the noi'th. The rail- 

 road sweeps around the south side of this curve, cutting through 

 several spurs and ridges of the mountains on that side of the 

 valley, at an elevation of some fifty feet above its bottom. Its 

 direction for several miles below the springs being very obliquely 



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