324 MKSOZOIC FLOIJAS OF rXlTKO STATES. 



Feet. 



10. Shale bed (or clay.* ) In-lmv I hi' cvcad Irvel Id 



9. A layer of ligliH-ojored sandstone 12 



S. Sandy .shaly mat erial 30 



7. Sandstone '>0 



B. Shale much like Xo. 3 65 



Xos. 3-() make a somewhat homogeneou.s series about 12.5 I'eet in thii'kness. 



5. Same shale in rharacter as that seen just below (4 ) 2 



4. Sandstone breakiii"; up into large bloeks (> 



3. Shale with nodular layers followed by very sluily material 4.") 



2. Marine Jurassic (Belemnite horizon ) 12o 



1. Red beds. 



The preceding section in:iy he supplemented by the following briefer 

 one, introduced merely to explain in a general way the continuation of 

 the thus far barren horizons, save for silicified wood, here forming the 

 summit of the rim: 



Section at Farkers Peak, risiny 2(1(1 ffel nhmv the cycatl horizon ami about 1(10 feet above ilaltie!' Peak. 



Feet. 

 4. A highly charaeteristic quartzitii- cap. forming, through its peculiar erosion about the head of Hells 



Canyon, 2 miles east of the peak, picture-scjue pine-clad mesas .SO 



3. Softer sandstones, mostly talus-covered; basal portions form mesas east of Parkci-s Peak .50 



2. Soft flesh-colored sand rock (pinkish or whitish ), forming cliff 50 



1. There should follow closely the red and yellow rock, followed beneath by the blue shale, between 



which two horizons are many of the cycads. At the head of the trail, 2 miles east of Arnold's 



ranch there is a distinct blue clay contact with the yellow cycad sandstone, and much silicified 



wood is present. 



There is occasional fossil wood on the tables mentioned in Xo. 3. 

 and there is a presumption that they correspond to certain high tallies 

 on the southern side of "Calico Canyon," which are about 100 feet below 

 No. 31 of that section and l)ear large quantities of silicified logs. 



In conclusion, I give a section from the extreme northern hills, 

 obtained at the office of the Aladdin (formerly Barrett) Coal Company, 

 and called by them the Bore Hole B section. Being the result of a Iwring, 

 it is most interesting to compare this section with that given l\y Mr. 

 Walter P. Jenney on page 582 of Ward's Cretaceous Formation of the 

 Black Hills. These sections are from the same point, Jenney's l)eing 

 the result of a surface examination of the finely exposed rim escarpment, 

 and this section the record of a boring. Whoever will take the pains to 

 compare these two sections will realize how difficult it is to correlate and 

 reconcile the sections of different ol)servers in the case of a highl\- 

 developed series of sedimentary rocks like that of the Black Hills rim in 

 the absence of positively identified fossils collected with care from horizons 



