COPPER ORE. 23 



June 3. — -We were in motion again at 3 o'clock this morning, our 

 course leading us directly towards a very prominent range of hills 

 situated upon the north bank of Red river, and immediately on the 

 crest of the third-terrace or bench bordering the river valley. Their 

 peculiar formation, and very extraordinary regularity, give them the 

 appearance, in the distance, of gigantic fortifications, capped with bat- 

 tlements of white marble. Upon examination they were found to con- 

 sist of a basis of green .or blue clay, with two super-strata of beautiful 

 snow-white gypsum, from five to fifteen feet in thickness, resting hori- 

 zontally upon a sub-stratum of red clay, with the edges wholly exposed, 

 and so perfectly symmetrical that one can with difficulty divest himself 

 of the idea that it must be the work of art, . so much does it resemble 

 masonry. In many places there are perfect representations of the re- 

 entering angles of a bastion front, with the glacis revetted with turf, and 

 sloping gently to- the river. Several springs issue from the bluffs, and 

 (as I have always found it to be the case in the gypsum formation) the 

 water is very bitter and disagreeable to the taste. 



I am inclined to believe that this same formation extends in a south- 

 westerly direction from the Canadian river . to 'this place, as I passed 

 through a belt of country upon that stream somewhat similar to this, 

 and in a position to be a continuation of it. We crossed the river near 

 the lower extremity of the bluffs, at a point where we found it fifty 

 yards wide and sixteen inches deep, with a current of three miles per 

 hour, running over a bed of quicksand. We passed without difficulty 

 by keeping the animals in rapid motion while in the stream, and en- 

 camped upon the high bluff on the south side. By following up the 

 course of a ravine in the side of the gypsum bluffs, where there were 

 detached pieces of copper ore, we discovered a vein of this metal which 

 proved to be the " green carbonate," but not of so rich a character as 

 that we had seen before. At this point we are nearly opposite the 

 western extremity of the chain of Witchita mountains.* 



* Professor Shephard's analysis of a specimen of the sub-soil from the valley of 

 the river near our camp on the third June, gives the following result : 



Silica 79.30 



Peroxide of iron 8. 95 



Alumina 1.50 



Carbonate of lime 1.10 



Sulphate of lime, with strong traces of sulphate of soda and chloride of 



sodium 4. 65 



Water 4.50 



100.00 



