288 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



DEVONIAN (MIDDLE) 

 Messines Formation 



reet Meters 



This section is essentially the same as that at 

 Clearwater Canyon, 17 miles (27.4 km.) northwest, 

 except that it is not overlain by the Pipestone forma- 

 tion of the Upper Devonian. I did not attempt to 

 measure it. 



Disconformity 



ORDOVICIAN 

 Skoki Formation 



10. Light gray siliceous and magnesian limestones in layers 

 15 to 24 inches (38.1 to 60.9 cm.) thick. In the lower 

 part the limestone is very fine, smooth, and with thin 

 layers and nodules in layers of bluish-gray chert that 

 weathers to a bufif and reddish-brown color 380 115.8 



Fauna. — Annelid trails on surface of layers and borings 

 in the coarser layers. 



lb. Thick-bedded, light gray, slightly arenaceous limestones 



in layers from 2 to 3 feet (.6 to .9 m.) thick 12 3.7 



ic. Light gray, hard, compact limestone, with thin layers, 



stringers, and nodules of chert similar to that in la. . 42 12.8 



id. Light gray, slightly arenaceous limestone in layers 2 to 

 6 feet (.6 to 1.8 m.) thick, which split up on weath- 

 ered outcrops into thinner layers 66 20.1 



Total of Skoki formation 500 152.4 



CANADIAN 

 Sarbach Formation 



la. Fine-grained, dark, steel-gray, magnesian limestone in 

 layers 3 to 5 feet (.9 to 1.5 m.) thick. A few irregular, 

 thin layers and small lentils of bluish-gray, hard lime- 

 stones occur within the thick layers, which give a 

 striped appearance on fresh breaks and a banded 

 effect where the magnesian layers weather out in 

 relief in rusty buff and brown colors 36 lag 



Fauna. — A few thin layers of a softer gray limestone occur 

 as an irregular band about 6 inches (15.2 cm.) 

 thick 18 feet (5.5 m.) from the base of 2a. (2iz) : 

 Megalaspis fauna. 



lb. Hard, gray, compact limestone with finely crystalline 

 structure in layers 12 to 40 inches (30.5 to 101.6 cm.) 

 thick, which break down into thin, irregular layers 

 and fragments on weathered outcrops 90 27.5 



If. Soft gray limestone in layers 6 to 30 inches (15.2 to 

 76.2 cm.) thick, which break down into small frag- 

 ments that quickly disappear on weathered talus 

 slopes 105 32.0 



