ECONOMIC GEOLOGY. 569 



PART II. 

 ECONOMIC GEOLOGY. 



HOW TO USE THE REPORT. 



The prospector, capitalist, or property holder who desires to make the most 

 of this Report as a guide to the probable outlook for the discovery of com- 

 mercially valuable products upon any given tract of land, may save much 

 needless labor and expense by proceeding as herein directed: 



I. Examine carefully the Topographic Map of the Central Mineral Region 

 (Plate XXIII) and determine the situation of the land with respect to prominent 

 points not far distant. Make a list of these, and use the index at the close of the 

 volume to ascertain the pages upon which such localities are specially mentioned. 



II. Turn to the different pages selected under I and read the references to your 

 neighboring localities, with the object of determining as nearly as may be the 

 geologic conditions of your immediate district. 



III. Observe the color or colors which the particular area holds upon the geo- 

 logic map (Plate XXIII.*) From this inspection determine the range of the 

 geologic systems in your vicinity. 



IV. Turn at once to Part I of this Report and read what is said of the rock 

 divisions under each system exposed near your property, from which you can 

 usually make out the general character of the rocks, and often by comparison 

 with what you actually find, you will thus be enabled to ascertain even the 

 minor division or subdivision to which they belong. 



V. In many cases the foregoing method faithfully pursued will afford direct 

 hints as to the character of the mineral resources which can justly be anticipated. 

 In such event a perusal of what is given under the appropriate headings in this part 

 of the Report will rarely fail to afford a decisive answer as to the probabilities. 



VI. Where the results of an inquiry made by this logical method are favora- 

 ble — that is to say, when you are reasonably certain that one or other of the 

 deposits of commercial worth is liable to exist upon your property — there are 

 open to selection two radically different methods of procedure. 



First, you may develop the claim under the advice of a thoroughly trained 

 mining engineer, whose knowledge and services are as important in this case 

 as are those of a lawyer or a doctor in his respective field of operation ; or, 



Secondly, you may adopt the more expensive and far less effective plan of 

 exploring the territory by such haphazard excavations as inexperience is sure 

 to dictate. 



* See foot note concerning; this map on p. 557 of this volume. 



