IRON ORES. 359 



3. THE HYDRATED IRON ORES. 



With such high grade bessemer ores as have been reported under the two 

 preceding heads the limonite series would fail to attract any business atten- 

 tion were it not for the unusually rich character of the ores of that division 

 which exist in our region. It is true that the outcrops are not very abund- 

 ant, and they rarely if ever occur in beds or in segregations of any magnitude. 

 Aside from the insignificant quantity which comes in as contaminations 

 through alterations of the anhydrous ores, these hydrous oxides appear almost 

 exclusively in veins, for the most part in the older rocks. The most important 

 fact connected with their distribution is their occurrence largely in places 

 where there is every reason to believe that they are connected with the buried 

 magnetite ores. They often pursue courses more closely related to the Fer- 

 nandan trend than to the principal fault lines at surface in the areas where 

 they outcrop, and where they do not follow this law there is usually an irreg- 

 ular development of the veins which roughly corresponds with the distribu- 

 tion of the magnetites in belts beneath them. 



Table IV gives analyses of ten samples of hydrated ores from various 

 localities. No attempt has been made to separate them into species. The 

 "loss by ignition" does not, of course, represent the exact proportion of 

 water in all cases, but the general relations of the ores may be understood 

 by reference to that column. Turgite, goethite, and limonite are the prevailing 

 types, some very fine radiated examples of turgite (No. 7) occurring near the 

 divide between Hinton Creek and Deep Creek on the Fredonia and SaD Saba 

 road. Numbers 6, 13, and 15, of Table III, are partly limonitic. In fact, 

 it is necessary to draw arbitrary lines, owing to mixtures of the principal min- 

 erals in the ores. Table III contains a striking example of this in No. 16. 



Some of the se viens have been worked by persons who have believed them 

 to be rich silver ores. No. 8, Table III, is an example from one of these 

 prospects. As will be seen by the analysis, it is a very good limonitic iron 

 ore, but with rather a high percentage of phosphorus, due no doubt to its 

 proximity to the greensand beds of the Potsdam Series. 



The limonites may become important sources of revenue in addition to the 

 other iron ores, although they are not abundant enough to sustain any in- 

 dustry by themselves. In some cases, however, as at the Chaney diggings, 

 southeast of Packsaddle Mountain, the quantity is sufficient for profitable 

 working, and the prospect for better ore (manganese or iron) below is very 

 good when the structure is considered. The conclusions here given are 

 based upon many more observations than can be well presented here. There 

 are many localities in the Silurian and Cambrian rocks where veins of this 

 kind overrun, especially in the San Saba River valley. 



