CLASSIFICATION OF ORE DEPOSITS. 53 



2. Animal (limestone, etc.). 

 (d) Complex (cannel coal, bog ores, etc.). 

 II. Of subterranean origin. 



(a) Filling fissures and cavities formed mechani- 



cally. 



1. Fissure veins, lodes. 



2. Cave deposits lead, silver, iron ores. 



3. Gash veins. The cavities of 2 and 3 are 



enlarged by solution of limestone. 



(b) Filling interstitial spaces and replacing the walls. 



1. Impregnated beds. 



2. Fahlbands. 



3. Stockworks. 



4. Bonanzas. 



5. Masses. 



1.06.13. This scheme covers all forms of mineral deposits, 

 whether metalliferous or not, while most of those previously given, 

 as well as the one that follows, concern only metalliferous bod- 

 ies. The scheme is consistently genetic and was elaborated be- 

 cause such a one filled its place in lectures on mining better than 

 one based on form. The general principle on which the main sub- 

 division is made differs materially from any hitherto given. De- 

 posits formed on the surface are kept distinct from those originat- 

 ing below, even though the first class may afterward be buried. 



(17) 



1.06.14. J. F. Kemp, 1892. Revised from the School .of Mines 

 Quarterly, November, 1892. 



I. Of Igneous Origin. Excessively basic developments 

 of fused and cooling magmas. Peridotite, forming 

 iron ore at Cumberland Hill, R. I. 1 Magnetite, Jacu- 

 piranga, Brazil. 2 Titaniferous magnetite in Min- 

 nesota gabbros 3 ; in Adirondack gabbros * ; in Swe- 

 dish and Norwegian gabbros. 5 



1 M. E. Wadsworth, Bull Mus. Comp. Zool., 1880, VII. 



2 O. A. Derby, Amer. Jour. Sci. , April, 1891. 



3 N. H. Winchell, Tenth Ann. Rep. Minn. Geol. Survey, pp. 80-83. 

 Bull. VI. of same Survey, p. 135. 



4 Forthcoming paper by J. F. Kemp. 



5 J. H. L. Vogt, Geol. Foren. i. Stockholm-Forhand, XIII. 476, May, 

 1891. English abstract and review by J. J. H. Teall. Geol. Mag., Febru- 

 ary, 1892. See also Zeitschr. fur Praktische Geologie, I. 4. 



