GEOLOGY — VOLCANIC TUFAS OF PSUC-SEE-QUE CREEK. 



47 



below ; a single column often being formed of several successive differently colored layers ; 

 the prevailing colors being pink, white, orange, blue, gray, and lilac, and these colors 

 frequently strongly contrasted, producing a very peculiar and pleasing effect. 



A 



* No. 1, columnar trap. 



< Nos. 2,4,6,8,10, 12,14, 16, 18, 20, 22, 24, soft tufas, 



and infusorial marls. 

 '-' Nos. 3,7, 13, 17, 21, 23, harder tufas. 



" -13 



Nos. 5, 8, 15, 19, concrete. 

 =» No. 11, trap. 



-J7 * 



. | — .-■--■-■---- | -,-yrr -ii^i i j j _■ 1 1 1 j_!j_!_i--^ 



SECTION OF BANK OF PrUC-SEE-QUE CREEK. 



Near the base of the series was a stratum of three feet in thickness, composed for the most 

 part of brilliant white felspathic pumice, so soft as to be easily crumbled in the fingers. Tbis 

 pumice was in somewhat rounded masses, averaging less than an inch in diameter, and 



.-■^ 



Concrete, brown. 



White ■) 

 Blue 





-Tufas. 



Pink 



Concrete, gray. 



COLOBED TUFAS, PSUC-SEE-QUE CREEK. 



cemented by a fine lilac colored clay. The general aspect of this layer was that of marbled 

 paper, the spots being pure white and the interstices lilac. A line of dark carbonaceous matter, 

 less than a quarter of an inch in thickness, marked the line of separation between this stratum 

 and another of nearly the same thickness, which was blue in color, having the texture of soft 

 pulverulent coarsish sandstone. The under surface of this layer was pierced in every direction by 

 holes as large as straws, left by the decaying branches of some small plant which had apparently 

 grown from the carbonaceous surface below. The appearance presented by these impressions of 



