456 ; NEW YORK STATE MUSEUM 



feet A. T. while in the present section it is 450 feet A. T. which 

 gives a dip of 140 feet a mile to the south. 



The thin bedded appearance of the Black river limestone (no. 4) 

 is apparently due to weathering. Almost uniformly the Black 

 river in this region appears massive in fresh exposures, but after 

 long exposure it exhibits an extremely irregular, lumpy structure, 

 giving the general impression of irregularly thin bedded layers. 

 The same is true of this limestone at Newport south of Trenton 

 Falls and seems to be a very constant character. 



Westward from this point the Calciferous is exposed in ledges 

 above the West Shore railroad and the Trenton is exposed at inter- 

 vals at an elevation of between 200 and 300 feet above the river. 

 Along the highway passing through the small hamlet of Scotch 

 Church are a number of exposures of the Utica shale, the highest 

 being at an altitude of 1040 feet A. T. at a point .8 of a mile north- 

 east of Scotch Church. The shale at this point is strongly cal- 

 careous, dull black with an olive tint, brown streak and weathers 

 greenish brown. It is disposed in thin even laminae with smooth 

 surfaces. Graptolites occur in moderate abundance but no other 

 fossil was found. Similar shale is exposed at a point one quarter 

 of a mile north of Scotch Church at an altitude of 1000 feet A. T. 

 Slabby calcareous layers of several inches in thickness occur in 

 the latter exposure. About one mile south by southwest of Scotch 

 Church the fragile shales and brown-weathering sandstones of the 

 Hudson river stage are exposed in the deep glen just west of the 

 highway between Scotch Church and Mariaville. This exposure is 

 at an altitude of about iioo feet A. T. or 860 feet above the level 

 of the Mohawk at Pattersonville. If the dip is 140 feet a mile 

 this would indicate a thickness of 950 feet of Utica shales. 



The Trenton is traced by its frequent outcrops in a narrow belt 

 nearly parallel to the Mohawk but gradually approaching it to the 

 westward. In both branches of the creek which empties into the 

 Mohawk two and one half miles west of Pattersonville are fine sec- 

 tions from the Calciferous to the Utica, and west of this creek a 

 series of quarries have been opened in the Trenton limestones and 

 afford an excellent opportunity for any study of these rocks. A 

 section was measured beginning at the level of the canal at the cut 

 on the West Shore railroad nearly opposite Crane's village. 



