APPENDIX D. GEOLOGY. 161 



May 12. — Red river, as observed to-day, runs through a thick bed of 

 red loam, which, mixing with the water, imparts to it highly charac- 

 teristic red sedimentary properties. Its bed was composed of fine sand. 

 After travelling about six miles we came to a small creek with high 

 bluff banks, near the base of which I observed a number of specimens 

 of green and blue copper ores. Associated with it, as a matrix, was a 

 porous and dark-colored igneous rock, containing disseminated parti- 

 cles of green copper ore. At this point I had an opportunity of ob- 

 serving the aqueous strata, from which I obtained the following sec- 

 tion : 



1. Black argillaceous subsoil ; six feet thick. 



2. Soft fine-grained sandstone, of a grayish color ; five feet thick. 



3. Red and blue clay ; from six to ten feet thick. 



These strata presented an easterly dip of nearly two degrees. I saw 

 during the day large quantities of drift and a few small boulders, com- 

 posed of granite, quartz, and greenstone porphyry. In a few hours we 

 arrived at Cache creek, which runs between high bluff banks composed 

 of red clay ; its bottom was thickly strewn with large, angular frag- 

 ments of quartz, greenstone porphyry, granite, and hornblende rock. 

 Within a short distance from the creek we found a small spring of clear 

 water, which was strongly impregnated with sulphuretted hydrogen gas. 

 Soil dark and fertile ; subsoil argillaceous, and of a deep-red color. 



May 14. — Did not move from camp. In the evening I rode to the 

 junction of Cache creek and Red river, near which point I observed a 

 stratum of finely laminated ferruginous sandstone ; in some places it 

 was interstratified with red clay, and presented a south-southeasterly dip 

 of three degrees, (see Section No. 3.) Saw scattered over the surface a 

 number of small boulders of the same composition as those of yesterday. 

 Soil black and fertile ; subsoil argillaceous. 



May 15. — Did not move from camp; tested the water of Cache 

 creek, and found it strongly alkaline. Its temperature was 75° F. 



May 16. — Passed to-day a number of long, low ridges, presenting on 

 one side a gradual slope towards the prairie level ; on the other, abrupt 

 precipitous terminations. They were, for the most part composed of 

 dark-colored scoriaceous rock, containing a moderate per-centage of 

 copper ore. About 8 o'clock we came to a small creek, near which I ob- 

 served a deposite of soft granite, which appeared to be undergoing rapid 

 disintegration. The banks of the creek were composed of horizontal 

 layers of finely laminated sandstone, deeply tinged with copper, and 

 resting upon a base of red indurated clay. Saw to-day large quantities 

 11 



