34 Reviews — Br. Hayden's Geological Reports. 



show that the shores of these ancient estuaries, lakes, etc., in which 

 this formation was deposited, supported dense forests of large trees, 

 and a growth of other vegetation far exceeding in luxuriance any- 

 thing now met with in these latitudes." 



The Middle Tertiaries have yielded a magnificent series of verte- 

 brate remains, including numerous species of IlyEenodon, Oreodon, 

 Hyracodon Machairodus, Ehinoceros, Hippopotamus, etc., with a 

 large number of extinct Chelonians. The Upper Group, besides 

 remains of Equus, Mastodon, etc., seems to be chiefly characterized 

 by recent species. 



In the Colorado district. Igneous rocks appear to be much more 

 prevalent among the sedimentary deposits than they are in the 

 North ; and in that beautiful valley of the Middle Park, a number of 

 outpourings of Basalt are described as being interstratified and com- 

 mingled with rocks of every age. 



In the mining districts the loads of precious and other metals are 

 restricted, it would seem, to those areas occupied by granitic and 

 gneissic rocks, and consequently to the mountains. In the plains, 

 however, lies one of the chief resources of the country — the nume- 

 rous and thick seams of excellent Lignite, contained in the Lower 

 Tertiary series. 



Accompanying Dr. Hayden's Colorado Eeport, is a description of 

 the various mines visited during the Survey by Mr. Persifer Frazer, 

 jun., mining engineer to the expedition, which is a mere transcript 

 of his rough field notes. With regard to the gold mining, all the 

 evidence given in this volume tends to prove the very transitory 

 value of the primitive Placer system of gold-seeking, and that gold 

 loads, to be properly won, require labour and expense quite as great 

 as do any other metallic veins. 



Before parting with Dr. Hayden, we will quote his description of 

 the famous Eed Pipe- stone Quarry, which may perhaps be acceptable, 

 if not to every geologist, to every reader of "Hiawatha" : — 



" On reaching the source of the Pipe-stone Creek, in the valley of 

 which the Pipe-stone bed is located, I was surprised to see how in- 

 conspicuous a place it is A single glance at the red 



quartzites here, assured me that these rocks were of the same age as 

 those before mentioned at James and Vermilion Eivers, and at 

 Sioux Falls. The layer of Pipe-stone is about the lowest rock that 

 can be seen. It rests upon a grey quartzite, and there are about five 

 feet of the same grey quartzite above it, which has to be removed 



with great labour before the Pipe-stone can be secured 



The Pipe-stone layer as seen at this point is about eleven inches in 

 thickness, only about two inches and a quarter of which are used for 

 manufacturing pipes and other ornaments. The remainder is too 

 impure, slaty, fragile, etc. This rock possesses almost every colour 

 and texture, from a light cream colour to a deep red, depending 

 upon the amount of Protoxide of Iron. Some portions of it are 

 soft, with a soapy feel, like Steatite, others slaty, breaking into thin 

 flakes, others mottled with red and grey. . , . There are indica- 



