LITTLE QUADRANT MOUNTAIN. 



37 



Another section, made by Mr. Wright, shows the sequence and thickness of 

 the beds from this horizon to the summit of the mountain. 



Section of beds exposed on south side of Little Quadrant Mountain. 



Num- 

 ber. 



Feet. 



Colorado 



■In 



Mica-hornblende-porphyry 125+ 



Carbonaceous shales. 



Dakota . - 



Ellis 

 sandstone, j 



I 



Ellis 

 limestone. 



Interval with no exposure 100 or 150 



10 Sandstone. 



Interval with no exposure 50 



Additional interval with no exposure 175 



Mica-hornblende-porphyry several feet thick, with sandstone in small exposures 

 below it in slopesbowing no other exposures. Number of feet given is height 



of slope 100 



9 Sandstone and conglomerate. These are here overlain by the mica-horn- 

 blende-andesite. The section was again continued at a place about 100 yards 



southeast from the last-ment' ined exposure 25 



Interval with no exposure 340 



8 Soft gray and drab beds, weathering into light-green shales 10 



7 Calcareous sandstone and limestone 50 



Interval with uo exposure 75 



6 Oolitic limestone 2 



o Fossiliferous shales, occurring as follows: 



Shale?, gray, soft 15 



Interval with no exposure 60 



Shales, gray, clayey, in cut of stream flowing from pass at west end of 



Little Quadrant Few. 



Limestone 30 



At the west end of Little Quadrant Mountain a branch of Fawn Creek 

 has cut back to a low divide separating this mountain from Gray Peak. 

 The lowest beds exposed by this stream are the Ellis limestones, which are 

 exposed in the gulch 25 feet deep near the forks of the stream. The beds 

 dip N. 25° W. at 10°. The strata contain numerous fossils and are quite 

 like the beds described later in the Fan Creek section. In the stream 

 channel above, there is an exposure of very fissile calcareous sandstone in 

 a ledge 5 feet thick, which is overlain by very arenaceous, granular, cross- 

 bedded, gray limestone, containing fossils which are mostly comminuted 

 and broken. This exposure is 20 feet thick, and the bed is overlain by a 

 sandstone containing a few scattered pebbles. The strike is S. 35° W., and 

 the dip is 10° NW. Above this the stream flows over a small exposure 

 of Dakota conglomerate, which is overlain by andesite-porphyry, forming a 

 cliff 75 feet high, over which the stream flows in a succession of cascades 

 This rock, which is an extension of the Gray Peak intrusion, is hornblendic, 



