HOODOO ZONE OF SQUARE BUTTE. 403 



Above this is seen tlie intensely white color of the naked npper slopes, 

 masses and |)recipitous walls of rock which rise ahove the bristling fringes 

 of hoodoos l)elow, a contrast rendered all tlie more intense l)y tlie white- 

 ness of the former and the black color of the latter. These peculiarities 

 are shown by figure 1, i)late 24, which is a view of the butte from the 

 lower slope on the southeast side, and by figure 2, plate 24, which shows 

 the south side of tlie })rolongation on the southeastern side of the moun- 

 tain and which has been previously referred to. It must be said, how- 

 ever, that the photograj)hs present only in a feeble way what is most 

 striking in nature. 



As one approaches still nearer and enters the region of l)lack mono- 

 liths, it is found to be a labyrinthine maze of small glens, separated by 

 towering masses and pinnacles of black rock. The hoodoos attain in 

 many places a height of from 100 to 150 feet, and from that sink in size 

 down to examples but a few feet in height. The attention is immediately 

 arrested by a peculiar and regular arrangement of a platy structure they 

 possess. They are built of a series of inclined disks, each a few inches 

 in thickness and oval to subangular in shape, and with rounded edges 

 which accentuate the disk- like form. Generally the disks decrease in 

 size from bottom to top, but there are many exceptions to this rule, and 

 in these cases strange and weird figures are produced, resembling colossal 

 statues, sarcophagi, etcetera. Occasionally the disks are not flat, but 

 slightly dished ; the hoodoo then resembles a pile of huge inverted watch 

 glasses. The })lane or hade of the disks is not horizontal, but slopes to 

 the outside in all directions around the mountain approximate!}^ parallel 

 to the prevailing slo[)e, which, indeed, is conditioned by this platy parting. 



The disposition is precisely like the dip and strike of sediments in a 

 domed anticline, and the resemblance at times to sedimentary strata is 

 quite striking, as may be seen in figure 1, i)late 25. 



The hoodoos are apt to be disposed in mdial trains around the moun- 

 tain slopes, each train growing consecutively smaller as it ascends. 

 Between them are the small wooded glens previous!}^ mentioned (see 

 figure 2, plate 25). 



The rock forming these strange pinnac^les is uniformly in all cases a 

 rather friable granular one, comi)()se(l ch icily of a basaltic augite, to which 

 their black color is due. 



The origin of these spiredike masses is partly ex[)lained by the frecpient 

 presence of large, often huge, sj)heroi(lal bowlders of white syenite rest- 

 ing upon their i)oints and often balanced in almost incredil)ly delicate 

 positions. As these masses wliich descended from the upper slopes are 

 hard, tough and feldspathic, they liave resisted weathering and erosion 

 much better than the crumbly, ciusily altered dark augitic vjiriety ujjon 

 which they fell, and ]iav(; tlius conditioned tin' construction of the jiin- 



