148 APPENDIX D. GEOLOGY. 



occurred the ferruginous sand, which occurs also upon Cache creek in 

 great quantities. We have not been so fortunate as to find any gold in 

 the specimens sent, although the sand has been carefully examined, and 

 two assays have been made of the quartz in the laboratory. Yet I can 

 easily believe that gold must exist either among that black sand, or in 

 the veins of ferruginous quartz — sometimes three feet wide — so common 

 in the Witchita mountains. 



It is well known that a good deal of excitement exists on this subject 

 at the present moment in Texas ; but the "gold diggings" there lie upon 

 the upper Colorado. From some able remarks on the subject in the 

 "Telegraph and Texan Register" of April 29th, by the editor, Francis 

 Moore, jr., I learn that the region where the gold is found is "a belt of 

 fifteen or twenty miles wide, which extends from the sources of the 

 Gaudalupe, by the Enchanted Rock, to the head of Cherokee creek, a 

 branch of the San Saba." The description of that belt which follows, 

 as you will see, corresponds very well to the region around the "Witchita 

 mountains. "The red granite rocks here crop out above the secondary 

 formations, and veins of quartz are found traversing the rocks in all 

 directions. The soil is generally of a red mulatto color, caused by the 

 decomposition of the red feldspar of the granite. These rocks resemble, 

 it is said, those of the gold regions of California and Santa Fe. A gen- 

 tleman who has recently visited the Nueces states that gold has also 

 been found on that river ; and if the report that gold has been found in 

 the Witchita mountains be correct, it is possible that this narrow belt of 

 primitive rocks extends quite through from the Nueces to those moun- 

 tains, a distance of about four hundred miles. It is mentioned in Long's 

 Expedition that a narrow belt of red granite is found jutting up through 

 the prairie region on the Des Moines river, in Iowa, and it is not im- 

 probable that this is a continuation of the primitive ridge, extending by 

 the Witchita mountains and the Enchanted Rock, to the sources of the 

 Nueces, and it may extend far above Lake Superior." As to this 

 northern extension of these gold-bearing rocks, I do not find much to 

 confirm the conjecture in Dr. Owen's late able report on that region, 

 although he does mention some red granite and some red clay ; but the 

 latter is probably alluvial. Yet, that these rocks may extend through 

 Texas, and even much farther north, is extremely probable. 



But though your discovery of gold will probably excite more atten- 

 tion, I feel that the great gypsum deposit of the West, which you have 

 brought to light, will be of far more consequence to the country. 



On your map I have colored this formation as you have marked it 

 out. Yet I cannot doubt, from the descriptions and sections, that the 



