90 GEOLOGY OF THE THIRD DISTRICT. 



At the mill in the bed of the creek, rising for about eight feet in the bank, is a yellow green 

 shale. It contains some fossils, among which is the Broad agnostis, and an Avicula yet 

 unnamed ; above which arc thin layers of limestone composed entirely of Shining orthis 

 (Orthis nitens), the same which occurs above the pentamerus limestone in the fourth district. 

 The mass is covered with about fifteen feet of alluvion, at the bottom of which were fragments 

 of light-colored hard limestone with ore adhering to it, showing that a deposit exists in the 

 vicinity. 



The last point in the district where the group was observed, was towards the west of the 

 town of Stirling, on the land of Peter P. Van Patten. There one of the ore beds exists near 

 the surface, numerous fragments being often ploughed up. 



The same fossiliferous iron ore, so characteristic of this group, is found, according to Dr. 

 Locke, in Clinton county, Ohio, near the bottom of the cUflf limestone, which is its proper 

 position. The peculiar fucoids of the Clinton group (the bilobe and unilobe) are also found 

 near Cincinnati in the same position, showing the extent of its range and the value of the fossil 

 character. 



11. NIAGARA GROUP. 



Lockport Group. Upper part of the Protean Group, of the Reports. Geodiferous Limerock 



and Calciferous Slate of Eaton. 



This group consists of hmestone of a dark blue or black color, and of dark shale or slate. 

 When the limestone is but small in quantity, it is in hemispheric concretions, whose parts 

 are more or less concentric to each other, like the coats of an onion. The group is very 

 thick in the fourth district, and forms the rocks of Niagara falls ; but it thins out to the east, 

 leaving not a trace to be seen east of a line passing south through the village of Mohawk in 

 Herkimer county. It first appears in Steele's creek, to the southwest of that village ; then 

 in Swift creek, near the road from Sauquoit creek to Paris hill ; at Hart's mill, on the east 

 branch of the Oriskany ; in the ravine back of Dr. Noyes' house, near Hamilton college ; in 

 Skanandea creek at Vernon village ; on the same creek also back of Turkey-street ; south of 

 Oneida lake ; in the north parts of the towns of Lenox and Sullivan in Madison county ; and 

 in the towns of Cicero, Clay, Lysander, Ira and Victory in Onondaga and Cayuga counties. 



From the east end of Madison county, it appears generally as a concretionary mass, in one 

 or two layers, enclosed in dark blue slate or shale, not hard, the concretions varying in size 

 from an inch to two or three feet in diameter. It is there too impure to be used as a lime- 

 stone, and it is but small in quantity ; but in Madison, and particularly in Onondaga and 



