188 GEOLOGY OF THE EUREKA DISTRICT. 



Feet. 



15. Yellow to buff sandy shales 40 



16. Bluish black, hard, compact limestone 12 



Fragments of fossils. 



17. Shaly sandstone in massive layers 52 



18. Gray arenaceous limestone 2 



19. (a) Buff sandy shale 40 



(b) Gray arenaceous limestone 30 



(c) Sandy calcareous shale 3 



73 



20. (a) Massive bedded bluish gray limestone 200 



Fragments of fossils. 



(b) Compact gray siliceous limestone, almost quartzite in places 400 



(c) Bluish black evenly bedded limestone 6 



606 

 Strike K 30 W., dip 10 E. 



21. Buff to pinkish argillaceous shale, with fossils, and a few interbedded 



layers of limestone from 3 to 15 inches thick 125 



Fossils: Eocystitesf? longidactyltis, Lingulella ella, Kutorginapannula, 

 Hyolithes billingsi, Ptychoparia piochensis, Oknoides typicalis, 

 Bathyuriscws howelli, aiid B. producta. 



22. Massive bedded siliceous limestone, weathering rough and broken into 



great belts 200 to 300 feet thick by bands of color in light gray, dark 

 lead, to bluish black ; on some of the cliff faces the weathered surface 

 is reddish 1, 570 



23. Bluish black limestone in massive strata that break up into shaly layers 



on exposure to the weather. The latter feature is less distinct 850 feet 

 up, and the limestone becomes more siliceous, with occasional shaly 



beds 1, 430 



Fossils : Near the summit specimens were found that are referred to 

 Ptychoparia minor. 



The upper limestone on the line of the section is not favorable for the 

 preservation of organic remains, but the same horizon a short distance to 

 the southward yielded a fauna similar to that from the Upper Cambrian at 

 Eureka, two species being identically the same, while two others, Beller- 

 ophon antiquatus and Dicellocephalus pepinensis, occur in the Potsdam sand- 

 stone of Wisconsin. 



Timpahute Range. Mr. G. K. Gilbert reports from the southern end of 

 Timpahute Range a section over 2,300 feet in thickness, which, taken 



