1036 



NEW YORK STATE MUSEUM 



recognizable. It may correspond to the Trenton conglomerate 

 of Rysedorph hill described by Ruedemann, 1 or it may be of still 

 earlier date. Its areal relations seem to indicate that it is 

 older than the Normans kill beds of Mt Moreuo. Boulders of 

 this rock have been found on Becraft mountain in such a loca- 

 tion that they could not well have been derived fiom any known 

 outcrop. They therefore suggest other outcrops to the north 

 or northeast of Becraft mountain. 



2 "HUDSON RIVER" SHALES 



Ruedemann has shown that the Hudson river shales do not 

 constitute a single stratigraphic unit but rather comprise all 

 the formations from the Beekmantown up to the top of the 

 Lorraine. Nevertheless, these shales constitute a formational 

 unit, with but slight lithic variations, representing continuous 

 deposition, and hence it is advisable to retain the local name, 

 Hudson river group or shales, for this series. At Mt Moreno 

 these shales contain a typical Normans kill fauna in the higher 

 beds. Clarke cites Coenograptus gracilis, Didy- 

 mograptus Sagittarius, D. tenuis Hall and other 

 species of graptolites. 2 In the lower beds Phyllograptus was 

 found by the Columbia field party. A recent visit in company 

 with Dr Ruedemann resulted in the rediscovery of the Phyllo- 

 graptus beds in the lower layers at the northwest end of Mt 

 Moreno. In these Dr Reudemann identified Phyllograptus 

 angustif olius Hall, Trigonograptus ensiformis 

 Hall, Climacograptus pungens Rued, (ms), Diplo- 

 graptus dentatus Brogn. and Phyllograptus pos- 

 t r e m u s Rued. (ms). Dr Ruedemann refers these beds to his 

 third Deep kill zone or zone with Diplograptus denta- 

 tus which may represent a Beekmantown horizon. Though no 

 fossils have been obtained from the Hudson river shales of 

 Becraft mountain, it is probable that they are of the same, or 

 perhaps somewhat earlier age. Some of the strata underlying 

 the mountain are somewhat more compact and firmer textured 



1 Ruedemann. Trenton Conglomerate of Rysedorph Hill. N. Y. State Mus. 

 Bui. 49. 1901. p.3. 



Oriskany Fauna of Becraft Mountain. 1900. p. 7, footnote. 



