South Dakota School of Mines 



65 



ECONOMIC MINERAL PRODUCTS 

 The badland formations have not as yet attracted any par- 

 ticular attention as sources of mineral wealth. This is due partly 

 to the absence of mineral variety and partly to the lack of local 

 demand for such materials as are available. 



Building Stone. Sandstones and limestones occur, but they 

 seldom meet the requirement of a high grade building stone. 

 They are nearly always thin-bedded and generally more or less 

 argillaceous. The sandstones are often of coarse or irregular 

 texture and poorly cemented. In view of the fact that excellent 

 building stone is extensively quarried not far away, near and 

 within the Black Hills proper, it would seem that the badland 

 stone gives little promise of utilization, except in occasional 

 places as a local convenience. 



Clays. Clays are in unlimited abundance and of consider- 

 able variety. Analysis show that they could be utilized in various 

 ways, particularly in the manufacture of brick and cement. 



Fullers' Earth, Some of the badland clays, especially those 

 of the Titanotherium beds, have the property of decolorizing 

 or clarifying oils, hence are known as fullers' earth. Many 

 places disclose clay of this character and from two localities, 

 namely, near Argyle anr near Fairburn, test shipments have been 

 made. It seems probable that by careful sampling, large quan- 

 tities of good material could be obtained. Prof. Heinrich Ries 

 of Cornell University, gives the following analyses for the local- 

 ities mentioned, analyses i, 2, 3, 6 being of material from near 



Analyses of Fullers' Earth From the Titanotherium Beds. 



Constituent. 



Silica (Si02) 



Alumina (AI2O3) 



Ferrous oxide (FeO) 



Lime (CaO) 



Magnesia (MgO) 



Loss on ignition 



Total 



a Fe203 



Per cent 

 68.23 



14.93 

 3.15 

 2.93 

 O.87 

 6.20 



Per cent 

 60.16 



10.38 



14.87 



4.96 



1. 71 



7.20 



96.31 99.28 



Per cent 



56.18 



. 23.23 

 ai.26 

 5-88 

 3-29 



b n.45 



101.29 



b H2O. 



