RAWLINGS PEAK. 161 



through which the raih'oad passes. Their greatest thickness exposed can- 

 not be less than 700 feet of beds, generally not more than a foot or two in 

 thickness of gray-white quartzite and sandstones, having something of a 

 reddish tinge on the weathered surfaces. The lowest bed found is a fine- 

 grained conglomerate, about 70 feet in thickness, made of small pebbles of 

 white quartz in a siliceous matrix, while the upper bed is a ferruginous 

 sandstone, about 15 feet thick. The only traces of organic life found in 

 them were a few indistinct fucoidal remains, but their general lithological 

 character, and position beneath well-defined Carboniferous limestones lead 

 us to consider them representatives of the lower Palaeozoic series of the 

 Laramie Hills. 



At the extremity of the eastwardly-projecting spur of Eawlings Peak 

 is an interesting deposit of red hematite. It forms a body some 20 feet 

 in thickness in the sandstones immediately underlying the lower limestone 

 bed. The extent of the body in strike could not be determined ; at the 

 time of visit, however, it had already been extensively mined for use as 

 a flux, and as a mineral paint, for which it is peculiarly valuable. The 

 ore is remarkably free from impurities, and contains almost the theoretical 

 percentage of iron; although its surface, when fresh, shows a metallic 

 lustre, it is so soft and fine-grained that a very slight attrition reduces it to 

 an almost impalpable powder of brilliant vermillion color. The horizon 

 of this deposit is probably represented by the ferruginous band found in 

 other parts of the ridge. Above the iron deposit at this point is a bed of 

 some 50 feet of drab limestone, so compact and fine-grained as to resemble 

 a lithographic stone. The same bed occurs capping the sandstones in the 

 low hills south of the railroad gap, where they furnish large springs, and 

 are overlaid by darker-colored limestone beds, all dipping 10"^ to the south- 

 ward, and soon disappearing beneath surface accumulations. 



On the western ridge, a few miles northwest of the railroad station, the 

 best section is obtained, where the beds dip 30° to 40° to the westward. A 

 thickness of only about 150 feet of the underlying quartzites is exposed on 

 the slopes of the valley. Above the ferruginous sandstone, which caps the 

 quartzites, is 50 feet of fine-grained drab limestone, darker in color toward 

 the base ; over this 30 feet of white siliceous limestone, succeeded by a bed 



11 DG 



