164 GEOLOGICAL SURVEY OF THE TEREITORIES. 



passed a vertical position, 30° to 40°. No liue of demarcation can be 

 found between} be divisions of tbe cretaceous. They all pass into each 

 other imperceptibly. 



The cretaceous beds are well shown, No. 2 continuing up into blue marly 

 limestone, which maybe regarded as No. 3; this passing up into the dark 

 shales of No. 4, which gradually passes up into a rusty yellow clay with 

 numerous calcareous concretions with Ostrea, BacuUtes, &c. This bed 

 contains calcareous sandstones filled with a small Turritella and bi- 

 valves. The cretaceous rocks of this region are best divided into upper 

 and lower cretaceous. These beds become suddenlyhorizontal in the plains, 

 but the conformity is complete. The conformity of the entire series of 

 the sedimentary beds is more perfect than I have seen it at any other 

 locality in the West. Here, for the first time, I notice the two sets of red 

 beds mentioned by Dr. Newberry, in his report of the Colorado Eiver. 

 They are well defined. The cretaceous beds are well marked. In the 

 section, from beds 11 to 19 inclusive, I am inclined to regard as Jurassic; 

 the second series of reddish beds, as.triassic; then some reddish per- 

 mian(?) sandstones, passing down into the carboniferous. 



Above the springs there is an extensive series of gneissoid rocks, in- 

 clining northwest. The changed and unchanged beds do not conform. 

 These gneissic rocks vary much in texture and color. The dominant 

 constituents are reddish feldspar and quartz, but there are thick beds of 

 the banded gneiss. For about two miles up the Gallinas Creek, above 

 tbe springs, these rocks rise up in grand mountain masses, nearly ver- 

 tical, and theu for ten miles or more we find the limestones, sandstones, 

 and shales of the carboniferous, resting in a nearly horizontal position 

 over the vertical edges of the gneiss. About four miles above the springs 

 I found two distinct species of lepidodendron in sandstone,, one of them 

 twelve feet long. They leave a cast in the sandstone perfectly round. 

 Still further up the creek we see the limestone resting directly on the 

 gneiss for half a mile. Usually these beds are so covered by debris 

 that they are obscured. As we pass up the creek the carboniferous beds 

 come down to the water's edge. Three beds of limestone, from ten to 

 thirty feet thick, are exposed on the sides of the hill. 



About eight miles above the springs the valley expands out, and the 

 gneissic and basaltic rocks form the lower mountain ridges. At the 

 bead of the valley there is a very striking basaltic mountain, with nearly 

 perpendicular sides, which forms a land-mark in this region. 



The hot springs are most beautifully located in the valley of Gallinas 

 Creek, just as it emerges from the mountains on the south side. The 

 springs are twenty or thirty in number, and some of them are quite 

 large. They vary in temperature from 80° to 140°. The spring from 

 which the water is taken for the bath is quite liot, at least 140°. The 

 supply is very abundant, enough to meet the demand for all time to come. 

 There is no deposit about the spring, and the water is as clear as crystal. 

 It was analyzed by Mr. Frazer, and found to contain carbonate of soda, 

 carbonate of potash, and chloride of sodium, the potash in excess. 



It will be seen at once upon what its medicinal qualities depend. 

 Every day in the week all the springs are occupied by women, in washing 

 clothes. The water makes most excellent suds, and the ease with which 

 the dirt is extracted from the clothes renders these springs great favor- 

 ites. There is every facility for the proprietors to establish a place of 

 resort for invalids and pleasure-seekers, when there shall be a sufhcieut 

 demand. 



West of the town of Vegas there is an almost vertical wall of creta- 

 ceous sandstone, running nearly north and south. Passing south along 



