610 CENTRAL MINERAL REGION OF TEXAS. 



distributing point. What effect the settlement of the surrounding country 

 may have upon these existing circumstances can not now be foreseen, but the 

 manifest interest of transportation lines is not in the direction of in-hauling 

 fuel so much as out-hauling ore. 



4. Assuming that Llano or some other point in the iron bearing tract be 

 chosen as the site of smelting furnaces, it would be necessary to find a mar- 

 ket for the product. This must lie within the State of Texas, or in a limited 

 area adjacent thereto. 



The present iron ores cover a very large area, but their outcrops are re- 

 stricted to very narrow bands persistently crossing the belt in parallel lines. 

 There is an important structural difference between them and the manganese 

 ores, although many observers would overlopk this important feature even in 

 working the deposits superficially. The iron ores which are not segregations 

 or secondary erosion products follow practically the same course as some of 

 the manganese veins. But the former are component parts of the Fernandian 

 system, folded and denuded in unison with the same; whereas the manganese 

 ores probably fill vein fissures of Post-Silurian date. Prom the strict paral- 

 lelism of the bands of the two areas, and from observations of the manganese 

 veins where they have been sufficiently eroded, it seems reasonable to infer 

 that they may become more ferruginous at greater depths, and exhibit there 

 the original facies of the true iron ores farther east. 



We have been unable as yet to give such topics their merited attention, 

 and it is doubtful if circumstances will permit of the necessary investigation of 

 them in tbe near future. The Economic Map accompanying this Report 

 (Plate XXII) shows the distribution of the ores in detail. A close examina- 

 tion and comparison with known outcrops will make it apparent that the po- 

 sitions of the ore belts are there indicated with precision.* The bands of 

 iron ore cross the roads and creeks and individual surveys exactly as laid 

 down upon the map, and the information given in the Report should be all 

 that is needed for the guidance of prospectors for many years to come. 



CLASSIFICATION OF IRON ORES. 



There are several varieties of iron ore in the Central Mineral Region, and 

 these may be classified in various ways, according to their composition, mode 



*This map is the result of the plottings of very numerous outcrops, and of observations 

 of dips and strikes, first upon the scale of one thousand and forty feet to one inch on con- 

 venient sheets, accurately reduced to about one mile to the inch and this again to one-half 

 that scale, then to one-fourth, and finally by photography to the published scale. As evi- 

 dence of the thoroughness with which the field and office work has been done, I may point 

 with some pride to the fact that of the large number of prospects of all kinds opened since 

 the notes were taken not one has been authoritatively reported which did not lie directly 

 in that one of the mineral belts defined upon this map to which the ore corresponds. 



