TYPICAL SHERBURNE 429 



Fifteen feet higher is another concretionary stratum which contains 

 Liorhynchus^ and the next exposures, some distance above this, carry the 

 Ithaca fauna and are referred to that horizon. 



The equivalent of the Sherburne beds is here absolutely continuous 

 with the Hamilton, which also contains many barren beds in its upper 

 part. The character of the fauna of these higher beds is clearly a 

 Hamilton one and shows the persistence in the waters east of the typical 

 Sherburne deposits of that fauna and its slow modification by the ap- 

 pearance of species of the Ithaca fauna. 



In the Schoharie Valley the horizon of the Sherburne is not well 

 exposed, being mostly a greenish or grayish sandstone with alternating 

 shales and indistinguishable lithically from the Hamilton below and the 

 Ithaca above. Fossils are much less numerous in this region, though plant 

 remains are not uncommon. Fossils are also much less abundant in the 

 underlying Hamilton, where great thicknesses of barren sandstones and 

 shales occur. The influence of the near-by Devonic land made itself felt 

 during the deposition of the later Hamilton and succeeding beds, all of 

 these being merely the seaward extension of the great Devonic delta of 

 the Appalachian region, the formation of which began in Hamilton time. 

 When fossils do occur in the Sherburne they are still of Hamilton types. 

 Xear Breakabeen bluish gray shaly sandstones 100 feet above t3^ical 

 Sherburne sandstone and 410 feet below red Oneonta shales carry 

 Tropidoleptus carinatus in abundance, while Spirifer mucronatus occurs 

 less frequently.^* East of Breakabeen, in bluish shales 335 feet below 

 red Oneonta beds, the following fauna occurs,^^ this being quite certainly 

 the Sherburne, which in this region lies 500 or more feet below the 

 Oneonta : 



1. Camarotcechia prolifica (a) 



2. Amhoccelia umhonata (rr) 



3. Strnphalosia truncata (rr) 



4. Pterinea flahella (c) 



5. Nyassa arguta (c) 



6. NucuUtes ohlongatus (rr) 



7. Palceoneilo constricta (rr) 



8. Nucula hellistriata (rr) 



9. TelUnopsis suhemarginata (rr) 

 10. TentacuUtes hellulus (r) 



In the Panther Creek section, along one of the branches of the West 

 Kill, in coarse grayish sandstones and thin blue shales, lying 140 feet 

 below shales carrying the Ithaca fauna, Prosser found^^ 



" Pi-osser : 17th Ann. Kept. N, Y. State Geologist, 1897, p. 181. 

 15L0C. cit., p. 178. 

 i« Loc. cit.. p. 192. 



