KAOLIN IX vriscoxsiN. 13 



A similar occurrence to the one just described is mentioned by 

 Jukes* as existing in the tilted bottom-beds of the Carboniferous 

 Limestone, on Cork Harbor, Ireland. Here, over a small area, the 

 limestone has been almost entirely removed, leaving the clay-like 

 substance behind. This clay has been used considerably in the Eng- 

 lish potteries. The following are analj'ses of those of the Indiana 

 and New Jerse}' bedded clays, which approach to kaolinite in com- 

 position: 



I. is a fine white clay from Burts Creek, near South "Amboy, New 

 Jersey, analysed just as it came from the pit. IL is a kaolin-like 

 clay analj'zed after washing to free from particles of quartz, mica, and 

 feldspar. It is from Trenton, New Jersey. III. and IV. are the 

 Lawrence county, Indiana, kaolin, analyzed without washing. 



II. — KAOLIN" IN WISCONSIN. 



Geograpfikal position of the kaolin district. — The fact of the exis- 

 tence of kaolin in Wisconsin has been known for many years. 

 The material has however only very recentl}^ attracted much atten- 

 tion and become the object of actual exploitation. The first pub- 

 lished mention I find of it is in the report of Dr. J. G. Norwood in 

 Owen's Geological Survey of Minesota, Iowa, and Wiscousin.f He 

 says,in describing the last Archaean exposui-e seen in descending the 

 Wisconsin River: " Above the granite at the old mill-dam, J is a 

 bed of ferruginous argillite four feet thick, succeeded by five feet of 

 decomposed felspar, above which is a bed two feet thick of well di- 

 gested kaolin, or porcelain claj', with * * * '^ quartz dissemi- 

 nated through it in veins and containing a notable quantity of 



*Jukes and Geikie's Manual of Geology, p. 130. 



X Near Point Bass, Wood county. 



P. 28!'. 



