1 6 NEW YORK STATE MUSEUM 



a little of the calcareous basal Utica shale, is shown. This 

 again contained Coryno. ides calicularis and 

 D i p 1 o g r . ( Me sogr.) mohawkensis. 



An excellent section of the Trenton and basal " Utica " shale is 

 exposed in Morphy creek, (title 33, page 654; title 44, page 

 460) halfway between Cranesville and Amsterdam and about 

 one and one-half miles west of the preceding section. Here 

 5 feet of Amsterdam limestone are overlain by 37 feet of 

 Trenton limestone. The uppermost 27 feet are thin, irregu- 

 lar, dark blue, limestone layers with very black shale intercalations. 

 These beds abound in Prasoporas, Trinucleus concen- 

 tricus, Calymmene senaria, but contain no 

 graptolites. The black calcareous Utica shale follows abruptly with 

 profusely graptolitiferous beds, the species being: 



Dicranograptus nicholsoni var. parvulus nov. 



Diplogr. (Mesograptus) mohawkensis nov. 



Diplogr. cf. putillus (Hall) 



Rafinesquina alternata ( Emmons) (small) 



Leptobolus insignis Hall 



Orthoceras sp. 



It follows from this series of outcrops that the Lower Trenton 

 or Prasopora zone at the eastern terminus of the continuous 

 " Utica " belt of the Mohawk valley is separated by a disconformity 

 indicating a small interval of nondeposition, from black calcareous 

 shales characterized by Corynoides calicularis 

 and a characteristic Diplograptus of the Mesograptus group. All 

 three of these ravines reach the drift directly above the basal 

 " Utica " beds and no satisfactory section of the upper " Utica " 

 could be obtained. The latter is found along the south branch of the 

 Chuctenunda creek, which empties opposite Amsterdam, and 

 reaches back into the " Frankfort " shale hills, southwest of the 

 village of Minaville where the transition from the " Utica " shale 

 into the " Frankfort " shale is finely exposed in the ravines. 



The contact between the Trenton and " Utica " is not shown 

 in the section; the first outcrop is found at the falls of the creek, 

 probably not more than 20 feet above the top of the Trenton. Here 

 were found (Museum locality number 3758) : 



i Diplograptus amplexicaulis (cc) 



Diplograptus (Mesograptus) mohawkensis (c) 



Lasiograptus eucharis (r) 



Leptobolus insignis (r) 



icc:=very common, c=common, r=rare, rr=very rare. 



