372 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



England, and their general application is of very doubtful advisability, 

 since authorities differ as to their exact definition. The term " gash vein " 

 is the only one recognized in the classifications given below, and is there 

 applied to a fissure which is confined to a particular rock or bed and which 

 does not extend into the adjoining rocks. 



The English literature of ore deposits is even more meager than the 

 German. Of general treatises on this subject, the more prominent in this 

 country are J. D. Whitney's Metallic Wealth of the United States, pub- 

 lished in 1854; an article by R. W. Raymond, in his Mining Statistics for 

 1869; and an admirable but little known paper on ore deposits, in John- 

 son's Cyclopaedia, by R. Pumpelly. J. S. Newberry has also published an 

 article on the origin and classification of ore deposits in the School of Mines 

 Quarterly for March, 1880. In England, J. Arthur Phillips published in 

 1884 an extended treatise on ore deposits. Of the classifications proposed 

 by .the above authors, those of Newberry and Phillips are nearly identical 

 with that of Whitney and Raymond's is avowedly an adaptation of Lottner, 

 the differences in either case being unessential for the purposes of the pres- 

 ent discussion. Those of Whitney and Pumpelly alone are therefore given 

 here, and to them is added that given by A. Geikie in his Text Book on 

 Geology (London, 1882), mainly because of the different standpoint from 

 which it is made. 1 



'Prof. Joseph Le Conte has also published an article on the Genesis of Ore Deposits, in the Amer- 

 ican Journal of Science fer July, 1883, in which a subdivision into (1) fissure veins, (2) incipient fissures, 

 (3) brecciated veins, (4) substitution veins, (5) contact veius, (6) irregular ore deposits, is given. 



