Prosser and CuMiNGSr— Lower Silurian Sections. 



653 



A s . Thin bedded, dark blue limestone; abounding in fossils, 5 F = e f 18 

 including Rafinesquina alternata (Con.), Hall and Clarke. 



This section presents several interesting features. The upper part of 

 No. 3, representing the Fucoidal member of the Calciferous formation, is of 

 unusually dark color and weathers almost as light as the Birdseye. The 

 surfaces of the layers are often covered with the markings which have 

 suggested the name by which this rock is known. In the side of Quarry hill, 

 the Calciferous sandrock seems to present a somewhat transitional character, 

 becoming less and less arenaceous toward the top. Capping these layers in the 

 eastern brow of the hill are the two and one-half feet of Birdseye mentioned 

 in the section; but just over the brow of the hill in the northeastern part of 

 the quarry the fossiliferous Black river beds are seen to rest directly on grey, 

 arenaceous rock. Apparently the Birdseye has totally disappeared within a 

 distance of two rods. In the western part of the quarry there is again a dove- 

 colored, fine grained limestone below the Columnaria horizon. In the central 

 part of the quarry the Columnaria ranges through from seven to nine feet of 

 very compact limestone. In this part of the quarry also occur the pebbles of 

 Calciferous (?) imbedded in a layer which caps the massive Black river bed. 

 This layer also contains several small specimens of Columnarid, but the latter 

 may have been derived in the same manner as the pebbles, from fragments of 

 lower strata. In the south side of the quarry the layers corresponding in 

 position to the Black river contain an abundance of iron pyrites and pockets 

 lined with crystals of white calcite. At this point the upper surface of the 

 rock is striated, the striae running N. 85° \\ . The dip is in general about 

 2^- g , S. 20° W. Vanuxem has noted the presence of pebbles about Amsterdam 

 similar to those mentioned above. Speaking of the base of the Trenton, he 

 says: ''One of the lower layers at Putnam's quarry [Tribes Hill] shows some 

 scattered irregular pebbles, forming masses or concretions having the same 

 character in all respects as the yellow-colored Calciferous sandrock, and 

 accurately resembling those observed in a quarry at Shelpintown [Rockton]; 

 the largest of .them are fully four inches in diameter and of greater length."* 



Section opposite Crane's Village on the south side of the Mohawk River. 



Opposite Crane's Villagef station, the cut on the West Shore railroad has 

 exposed the Calciferous sandrock, and a section, beginning at this point, is as 

 follows : 



* Geology of New York, Part HI, 1842, p 41. 



t This place is given as Cranesville on the Amsterdam sheet of the United Slates Geological Survey ; but is known locally as 

 Crane's Village and is so given on the timetables of the New York Central and Hudson River railroad 



