148 NEW YORK STATE MUSEUM 



Calciferous limestone to the east, which doubtless rests on it, 

 though the intervening connection is concealed by drift. 



calciferous. The Calciferous is exposed in only one place, 

 which lies east of the hotel and stretches for some distance along 

 the road leading northeast from the Roman catholic church. It 

 is a non-fossiliferous, silicious limestone with nodules of white 

 calcite. Cherty streaks were also observed. The limestone has 

 a very slight inclination to the west. The thickness of the forma- 

 tion could not be determined, but in a brook valley, near its east- 

 ern limit, several feet were exposed, so that from the general rela- 

 tions a thickness of about 30 feet was estimated. 



Under the microscope the limestone appears as a rather fine 

 grained aggregate of dolomite crystals of about .01 of an inch 

 (.2 mm) on the average, and quite richly set with rounded, water- 

 worn grains of quartz, two or three times the diameter of the 

 dolomites. In a slide from an outcrop about 100 rods east of the 

 hotel the quartz grains make up one third the material. There 

 are also round areas that suggest organisms, but no definite struc- 

 ture could be made out. Evidently the original of the dolomite, 

 probably a limestone, was exposed to the sweep of rather swift 

 currents and the incursion of moderately coarse sediment. 



Trenton. The Trenton is in many respects the most interest- 

 ing and significant of all the paleozoic exposures. It is a lime- 

 stone that varies from light gray to almost black. It occurs in 

 two places. The southern exposure, which lies on the west bank 

 of the river, due west from the Catholic church, consists of loose 

 boulders, which are not positively in place, but which are thought 

 to be on the spot of the parent ledges. Comparatively little at- 

 tention has therefore been given by us to this locality. The ex- 

 posure of chief interest lies north of the Lake Pleasant (or Sage* 

 ville) road and comprises a number of loose blocks and one large 

 ledge that is certainly in place. The latter has received our 

 special attention, and from it the material here noted was derived. 

 The ledge is about 60 feet long, 30 feet wide, and 10 feet thick. 

 Over the large blocks grassy hummocks of rectangular shape have 



