THE SHINAEUMP. 



145 



cate. In the Shindrump they are mostly strong, deep, and so rich as to 

 become cloying. Maroon, slate, chocolate, purple, and especially a dark 

 brownish-red (nitrous-acid color), are the prevailing hues, while one heavy 

 sandstone bed is yellowish brown. At the base of the series is a thick 

 mass of perishable shale not so conspicuous in its colors ; it is in the mid- 

 dle members that they are so resplendent. Alternating horizontal belts of 

 varying tones and shades, not merging into each other by gradation, but 

 like ribbons joined at their edges, are seen wherever the formation is ex- 

 posed in the same general vertical succession, and give the Shindrump Cliffs 

 an aspect most constant, peculiar, and wholly unlike any others Here 

 and there a thin line of white trenchantly separates the dark layers, em- 

 phasizing the distinctions, while the brown sandstone above heightens the 

 contrasts. The effect upon the mind is impressive and oppressive. 



Probably the most striking characteristic of this formation — one which 

 is destined to make it one of the most notable of the freaks of nature in 

 the popular estimation — is to be found in the architectural forms which 

 have been carved out of it by the process of erosion. A common style 

 of sculpture is represented by heliotype XI, taken from the southeastern 

 flank of Thousand Lake Mountain. Probably the most striking forms are 

 the buttes, which are often seen fringing the long lines of cliff bounding 

 the Shindrump terraces in the San Rafael Swell, and again near the junc- 

 tion of the Grand and Green. These last have been described in glowing 

 terms by Dr. J. S. Newberry and by Professor Powell. 



The age of the Shindrump is either Permian or Lower Triassic. To 

 which of the two periods it should be assigned is not yet free from doubt. 

 Within the limits of the Plateau Country no fossils have yet been discov- 

 ered which give a satisfactory solution to this question. Mr. E. E. Howell 

 found in the shales south of Kanab, lying at the base of the formation, a 

 small number of fossils which were so poorly preserved that only generic 

 characters could be asserted with confidence. If any conclusion were to 

 be drawn from them it would be that their general aspect is Jurassic. But 

 the whole Triassic series, and most of the Shindrump itself, overlie the hori- 

 zon from which they came, and, moreover, the types are well known to have 

 a gi'eat vertical range. 

 10 H p 



