142 Journey to the Coteau des Prairies, §c. 
a correct theory with regard to the. time when, and the manner 
in which, this formation was produced. That it is a secondary 
and sedimentary deposit, seems evident; and that it has with- 
stood the force of the diluvial current, while the great valley of 
the Missouri from this very wall of rocks to the Rocky Moun- 
tains has been excavated and its debris carried to the ocean, I 
confidently infer from the following remarkable fact. 
At the base of the wall and within a few rods of it, and on 
the very ground where the Indians dig for the red stone, rests a 
group of five stupendous bowlders of gneiss leaning against each 
other, the smallest of which is twelve or fifteen feet, and the 
largest twenty five feet in diameter, weighing, unquestionably, 
several hundred tons. These blocks are composed chiefly of 
feldspar and mica of an exceedingly coarse grain, (the feldspar 
often occurring in crystals of an inch in diameter.) The surface 
of these bowlders is in every part covered with a gray moss, 
which gives them an extremely ancient and venerable appeal- 
ance, while their sides and angles are rounded by attrition to the 
shape and character of most other erratic stones which are foape 
throughout the country. 
That these five immense blocks, of precisely the same nat 
acter, and differing materially from all other specimens of bowl-— 
ders which I have seen in the great valleys of the Mississippi and — 
Missouri, should have been hurled some hundreds of miles from 
their native bed and lodged in so singular a group on this eleva- _ 
ted ridge, is truly matter of surprise for the scientific world, as 
well as for the poor Indian, whose superstitious veneration of 
them is such that not a spear of grass is broken or bent by his 
feet, within three or four rods of the group; where he stops and in 
humble supplication, by throwing plugs of tobacco to them, soli- 
cits their permission (as the guardian spirit of the place) to dig 
and carry away the red stone for his pipes. 'The surface of these 
bowlders I found in every part entire and unscratched by any 
thing, and even the moss was every where unbroken, which un- 
doubtedly remains so at this time, except where I applied the 
hammer to obtain some small specimens, which I brought away 
with me.* 
ee ee ae 
5 Bex, a seinen’ with which we are favored by Mr. ss the feldspar is in dis- 
tinct crystals, is aoa ma and greatly abounds; the quartz is gray and w ares 
the mica black, while the moss covers nearly half the mass.—Eds. 
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