Carboniferous Algal Deposits. 347 



Algal Deposits of the Bad River and Ironwood Formations. 



The Bad River dolomite (Lower Huronian) and the 

 Ironwood formation (Upper Hnronian) of the Gogebic 

 Range contain algal deposits. These from the latter 

 formation are composed of chert and form a bed which 

 is 5 to 6 inches thick. 12 The structure is laminated with 

 the conspicuous divisions between laminae from a half to 

 a millimeter apart. The laminae and the upper surface 

 are domed, with the domes not more than an inch across. 

 The material which the writer had for examination is 

 hardly sufficient for detailed description. The writer has 

 not seen the algal material from the Bad River dolomite. 

 According to Doctor Hotchkiss they do not form colonies, 

 but occur as isolated individuals in the dolomite. They 

 are of domed shape and vary from 3 to 6 inches in diam- 

 eter. 



Pennsylvanian and Permian Algal Deposits. 



In southeastern Cowley County, Kansas, the beds 

 belonging to the Crouse limestone member of the Per- 

 mian system contain an abundance of algal ccenoplases 

 of the "water biscuit" type. A section illustrating the 

 occurrence is as follows : 



25. Wreford limestone member (summit of the section). 



24. Largely concealed, partly red gritty shale 40 to 50 feet. 



23. Brown, medium- grained sandstone 3 feet. 



22. Mostly concealed, some red shale and brown sandstone . . . 

 9 feet, 



21. Gray semi-crystalline limestone 4 to 5 inches. 



20. Mostly concealed, some shale and brown sandstone 



9 feet. 



19. Wave ripple-marked, gray weathering semi-crystalline 

 limestone; rarely seen in position, generally occurring as slabs 

 on slopes 12 inches. 



18. Mostly concealed, but some shale and thin limestone 



11 feet, 



17. Two beds of fine-grained gray limestone, weathers full of 

 round vertical holes, rings when struck 16 to 18 inches. 



16. One bed of gray, semi-crystalline limestone, poorly fossil- 

 if erous, weathers full of round vertical holes 12 inches. 



15. One bed of gray limestone filled with Fusidina 6 inches. 



14. Thin-bedded limestone, bedding poorly defined, contains 

 many Fusidina and other fossils, many being thinly incrusted 



with calcareous material which is probably of algal origin 



15 inches. 



12 Hotchkiss, W. O. : personal communication. 



