NO. 5 PRE-DEVONIAN PALEOZOIC FORMATIONS 335 



Feet Meters 



Sullivan Formation 



la. Shale and thin layers of limestone 200 feet (60.9 m.) 



from summit 125 38.1 



lb. Massive-bedded, steel-gray, rough-weathering, cliff- 

 forming limestone in three thick bands 240 73.2 



Fauna. — Fragments of trilobites and annelid trails on sur- 

 face of some layers (64h) : 

 Olwlus 



LingulcUa issc Walcott 

 Diccllovius nanus Meek 

 Dicellomus politus Hall 

 ic. Thin layers of light-weathering, gray limestone, with 

 darker siliceous layers interbedded, giving a narrowly 

 banded or ribbon-like appearance to the surface of 



the cliffs 140 42.7 



Fauna. — (64g) : 



Crinoid fragments 

 Lingulella isse Walcott 

 Dicellomus politus Hall 

 id. Rough-weathering, steel-gray limestone in thick layers. 30 9.1 



le. Dull to steel-gray, hard, compact limestone, with more 

 or less interbedded gray, oolitic limestone. The layers 

 are from 6 inches (15 cm.) to 3 feet (.91 m.) in 

 thickness and form massive bands and a solid wall in 



face of cliffs 155 47.2 



if. Hard, dull gray, compact, oolitic limestones in layers 

 varying from an inch (2.54 cm.) to 4 feet (1.2 m.) in 

 thickness, with beds of shale separating nearly every 

 layer of limestone, but bands occur with very little 



shale 570 1737 



Owing to shale bands this series breaks down 

 readily and forms a long shelf on the cliffs when the 

 dip is 20° or over. 

 Fauna. — (65I) : 



Dicellomus sp. 

 Eoorthis sp. 

 Hyolithes sp. 

 Agnostus sp. 

 Crepicephalus sp. ? 



Total thickness of Sullivan formation 1,260 384.0 



Arctomys Formation 



la. Dark gray, somewhat arenaceous limestone in bands of 

 thin and thick layers. Many of the layers are almost 

 made up of flat concretionary or interformational 

 pebbles and small round concretions 255 77.7 



lb. Massive-beds of steel-gray, fine-grained limestone, 

 breaking down into slabby layers and weathering light 

 gray 185 56.4 



