GEOLOGICAL REPORT. 



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good adobes (unburnt brick), as do the other clays of that neighborhood. The salts 

 give this clay valuable properties as building material. Mixed with four parts of sand, 

 it forms a superior plaster, and, stirred up in water, after the heavy part lias settled 

 down, it is advantageously used as a whitewash, because it adheres better to the wall 

 than lime-water. This clay was extensively used in the erection of the buildings of 

 Camp Floyd. 



Mineral springs. — I have spoken of them in another place. Some of them may 

 have strong medical properties, especially on account of the iodine, of which I have 

 discovered indications in the hot springs of Kobah Valley, of which a description 

 has been given above. It is not unlikely that this powerful remedy might also be 

 found, by analysis, in others of these springs more favorably situated. 



Stone-coal — In speaking of the stratified rocks, 1 have mentioned that the exist- 

 ence of true stone-coal, of the Carboniferous formation, although possible, is still 

 doubtful, and that those coals which are found in the Wahsatch range, in San Pete 

 Valley, and near Little Salt Lake, are probably equivalents of the coal on Sulphur 

 Creek, &c, on the eastern slope of that range, of which I have spoken in section IV. 



As this coal is much used in the Salt Lake Valley, and on account of its geo- 

 graphical proximity to the Basin (the limits of which it seems to cross farther south,) 

 I have to mention it again. The San Pete coal looks like true stone-coal, breaks in 

 cubical fragments, has a dark-brown streak, and is bituminous. It is superior to any 

 coal which I have seen west of the Mississippi River coal-fields, although it may be 

 equaled by the Sulphur and White Clay Creek coal, if they are taken from the depth. 

 It cokes to a certain degree, and can, therefore, be used for all purposes, like coking 

 stone-coal, either fresh or as coke. In case a railroad should be built in that direction, 

 the coal-beds in San Pete Valley or their equivalent at some other point, would probably 

 have to furnish the motive power for several hundred miles of road. 



Topaz, perfectly colorless and transparent, and of great beauty and luster, has 

 been found in considerable quantity, loose on the surface, in Colonel Thomas's range. 

 I did not see any in the rock, but it apparently originates from one of the trachytic 

 porphyries in that neighborhood. Its degree of hardness is = 8. Before the blow-pipe 

 it proved infusible, and when strongly heated it was covered with small blisters, but 

 did not show any change of color. It exhibited the re-actions of fluorine, alumina, 

 and silex. (No tests for other elements were made). The largest of the crystals 

 measured scarcely one-third of an inch in the direction of the basal cleavage, which 

 was highly perfect. The crystals were all short columnar, with various modifications, 

 corresponding to the following crystallographic expressions, according to the system— 





Of Rose. 



°">~ 





ot c': b\ 2 a 



c: b\ °° a 

 i c: b: a 



I 

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