64 CLASSIFICATION OF THE PUBLIC LANDS. 



currence of economically important minerals. On the map accom- 

 panying this report most of the finer details are omitted and only 

 geologic formations and the outcrops of coal, phosphate, or oil sands 

 are shown. The general report on a field contains a description of 

 all that is known of the physical and chemical properties of the 

 minerals occurring in that field. This report then serves as a basis for 

 a set of general minutes, in which the appropriate section of the board 

 outlines the application of the regulations governing the classifica- 

 tion of lands containing those minerals to that particular field. 

 After the general report has been considered by the proper section 

 and the general minutes have been written, the field geologist pre- 

 pares the classification data and in the case of coal land makes the 

 valuation, under the immediate supervision and with the assistance 

 of some member of the coal section of the board. Later the record 

 is reviewed and passed on in detail by the entire section. Each 40- 

 acre tract, and sometimes even each 2i-acre tract, is considered indi- 

 vidually and all facts affecting its classification as mineral or non- 

 mineral are weighed. A report of the proceedings of the section for 

 each township is prepared, giving in detail the result of the classifi- 

 cation and the reasons therefor. This report becomes part of the 

 permanent records of the land-classification board. 



Detailed reports on each township examined, with accompanying 

 large-scale maps, constitute the second form of data. These are pre- 

 pared in addition to the general report for all areas on which the 

 smaller-scale map will not suffice for Classification. On these large- 

 scale township maps every feature that is possible of cartographic 

 portrayal is represented — the outcrops, dips, and measured thick- 

 nesses of all coal or phosphate beds or oil sands, all mines, prospects, 

 or lodes, the location of these features with respect to established 

 land lines, and, if essential, the topography of the surface. Each 

 map is supplemented by a description which gives the dates and 

 methods of field work, the condition of land surveys, the proximity 

 to railroads, and a discussion of the geology. In the valuation of 

 coal land all calculations by which the price per acre for each tract 

 has been derived are given in detail. 



These reports and maps are all permanently mounted, arranged 

 in order of State, range, and township in loose-leaf locking binders, 

 and filed in fireproof steel cases. As new information is acquired, 

 from whatever source, with regard to the mineral character of any 

 township, it is added in its proper place in the binder. Such in- 

 formation consists of reports from field agents of the General Land 

 Office, data obtained by members of the Geological Survey on subse- 

 quent examinations, affidavits of public-land claimants, and other 

 matter. The original field sheets and notebooks are likewise de- 



