^S NEW YORK STATE MUSEUM 



Near the north end of the belt of Black River-Trenton limestone 

 shown on the geologic map, and one-sixth of a mile a little east 

 of north of the limestone quarry, a number of large angular chunks 

 (2 to 8 feet long) of Trenton and Lowville limestone were found. 

 These clearly indicate close proximity to concealed ledges of these 

 rocks. If the Pleistocene deposits were removed the Lowville would 

 certainly be seen as a continuous exposure within the belt mapped 

 as Black River-Trenton.^ 



Trenton limestone. The Trenton limestone is wholly confined to 

 the west side of the river, the best place for the study of the forma- 

 tion being three-fourths of a mile north of the north end of the 

 village and in the immediate vicinity of the quarry there shown on 

 the map. The rock may be seen in the small quarry, in a big ledge, 

 and in large, loose blocks. In the quarry the rock is rather thin- 

 bedded, very fine-grained, dark-colored limestone with very thin 

 shale partings and numerous fossils. A thickness of about 8 feet 

 is shown. The strike is north 50° east, dip 10° west.- 



The big ledge which lies about 30 or 40 rods southwest of the 

 quarry is some 50 or 60 feet long and shows a thickness of 10 feet 

 with strike and dip practically as in the quarry. The following sec- 

 tion is modified after Kemp, Newland, and Hill : - 



5 Rather thin-bedded, fine-grained, black limestone with thin shale ^^- ^^■ 



partings and abundant fossils 2 



4 Heavy-bedded, gray, crystalline limestone rich in fossil fragments. 

 Contains numerous sand grains and occasional pebbles of Pre- 



cambric rock 2 6 



3 Hard, coarse, crystalline, gray limestone in eight layers with many 



well-preserved fossils 3 6 



2 Dark gray, fine crystalline limestone i 



I Hard, crystalline limestone with abundant brachiopods i 



Pebbles, up to 3 inches across, of a smooth dove-colored (Low- 

 ville?) limestone are quite common in this section. As Kemp says ^: 

 " Layer number 4 is a most remarkable rock, being a limestone but 

 containing large quantities of quartz sand and in places large pebbles 

 of the old crystallines. The sand under the microscope is mostly 

 well rounded and abraded, but some grains are angular." Many 



1 The Trenton limestone is stratigraphically more closely related to the 

 Canajoharie shale than to the Black River limestone, but because of the 

 thinness of the two limestone formations it has seemed best to represent 

 them together upon the geologic map. 



2 N. Y. State Geol. i8th Annual Rep't, 1898, p. 149. 



3 Op. cit., p. 150. 



