﻿1861.] 



HECTOR — ROCKY MOUNTAINS, ETC. 



409 



bituminous coal, friable, and only to be obtained in small cubical 

 fragments, while some of it can hardly be distinguished from 

 charcoal, but all varieties have a deep purple-brown colour, which 

 is well seen when a portion is reduced to powder. A sample of this 

 lignite has been analysed in Dr. Percy's laboratory, at the Museum 

 in Jermyn Street, by Mr. Charles Tookey, with the following 



results : — 



Carbon . 56-50 



Hydrogen 3-65 



Oxygen 18-91 



Nitrogen 0-80 



Sulphur 0-60 



Ash 5-62 



Water (hygroscopic) 13-92 



100-00 



The sandstone which forms bed c is composed of very fine pure 

 grains of quartz, hardly cohering ; but in the upper parts of the bed 

 there occur concretions impregnated with clay and iron, and of a 

 reddish hue, that are comparatively hard and decompose concre- 

 tionally. This irregular disintegration gives rise to a curious 

 formation of the banks of the valley, which has rendered this lo- 

 cality an object of great superstition among the Indians. The lower 

 sandstone wears away from under the hard concretions, that assume 

 the form of compressed spheres, and sometimes long cylinders like 

 the boilers of a steam-engine, which are left supported on pillars of 

 the white sandstone. The gulleys which join the main valley are thus 

 filled with grotesque forms, sometimes exactly resembling the half- 

 buried remains of ruined edifices. The sandstone (m) at the base of 

 the section is also very incoherent, but is composed of larger grains 

 of quartz. The strata are not found in the same order and propor- 

 tion throughout the valley, but yet they always appear to be hori- 

 zontal. The marly shales (lettered I) have a considerable quantity 

 of selenite disseminated as small crystals. La Eoche Percee is in 

 latitude 49° & N., and longitude 103° 54' W. 



This formation has, without doubt, been much more extensive, 

 and has overlain the Cretaceous beds as far north and east as the 

 great sandy waste where the track of the Expedition crossed the 

 Souri Eiver in latitude 49° 30' K, and longitude 100° 20' W. At 

 that place the sand-hills rise 70 and 80 feet, so pure and so feebly 

 bound by the few plants that grow on their surface that they are 

 constantly windblown. Under these, and cut through by the Eiver 

 Souri, was observed a lacustrine deposit in which one bed was com- 

 posed wholly of rolled fragments of lignite, overlain by sandy marls 

 and gravel, enclosing fragments of bones which Professor BIuxle3 r 

 refers to the Bison ; and along with these were small land- and fresh- 

 water shells. This deposit has been found in one of the lakes, which 

 I referred to generally as of Quaternary age when describing the 

 superficial deposits of the prairies. The origin of this one has been 



