REPORT OF THE STATE PALEONTOLOGIST I9O3 345 



gradual one, the conglomerate or the sandstone (Oswego) being 

 transitional into the Medina. The lower portion of the Medina 

 throughout the central portion of the State contains pebbles abun- 

 dantly and is also characterized by an oblique laminated structure 

 which is well shown in the exposures of the Medina in Herkimer 

 county. On the other hand the base of the red shales (=High Falls 

 shales) above the Shawangunk grit in Ulster county and far- 

 ther southwestward do not possess the transitional features 

 ascribed to the Medina of central New York. In the eastern 

 section these shales are entirely devoid of pebbles, generally of 

 a bright red color and uniform in character, specially near their 

 base. On exposure to the atmosphere they break into small 

 angular fragments which are easily washed away leaving the 

 sloping surface of the conglomerate beneath clean and white. 

 In small protected areas on the western face of Shawangunk 

 mountain, where the agencies of weathering and erosion have 

 been less severe and the shale, perhaps, of a firmer texture, a 

 number of isolated patches of these red shales occur. They 

 are, however, easily removed and the underlying conglomerate 

 brought to view. On the farm of Patrick Winn at High Falls 

 the contact of these red shales with the conglomerate is favor- 

 ably shown. At this place the shales formerly were quarried 

 and used for making paint. They here retain their characteristic 

 features down to the conglomerate. It is evident then that there 

 is a very marked change in the character of the sedimentation 

 following the conglomerate, suggestive of a hiatus at this point. 

 Nowhere in central New York has the base of the Medina the 

 features presented by the red shales of this section. In litho- 

 logic features they are more like the Vernon red shales of the 

 Salina than any bed of the Medina, though in the upper portion 

 of the Medina there are beds of red shales of a somewhat similar 

 character but more arenaceous. Such beds can be favorably 

 examined at Lewiston on the Niagara river. 



A study of the overlaps on the west side of the Helderberg 

 shows that the Salina shales extend farther east than does the 

 Medina, and since the period was one of increasing submergence, 



