ROCK FORMATIONS ON FRYER HILL. 449 



max No. 5, 115 feet; Dunkin No. 1, 110 feet; Montana shaft, 99 feet; Amie 

 No. 2, 163 feet; Little Chief No. 1, 135 feet. It will be noticed on the 

 map that this lower sheet of White Porphyry gradually passes up across 

 the body of Blue Limestone to the southward towards Carbonate Hill, finally 

 merging with the upper sheet. 



Weber quartzite. — The ovcrlyiug quartzite is coarse-grained and sometimes 

 micaceous, as is common in the Weber formation. It occurs in detached 

 patches at various points between the ore body and the overlying porphyry. 

 Its most continuous body is in the Chrysolite ground, where it extends from 

 the Roberts shaft towards Chrysolite No. 4, and varies in thickness from 

 one foot to six feet. In the Roberts shaft, where its maximum thickness 

 occurs, it is separated from the iron body by ten or fifteen feet of porphyry. 

 In a drift from the Roberts shaft to Chrysolite No. 4 it is found sometimes 

 resting directly on this iron, again separated by several feet of porphyry, and 

 at other times split up into several bodies. Elsewhere on the hill it is gen- 

 erally found in more or less rounded fragments, included in the porphyry, 

 directly above the iron. 



Blue Limestone. — Small irregular bodies of pale-blue sand, generally near 

 the surface of the ore, are frequently found in the vein material of Fryer 

 Hill, especially in the Chrysolite ground. The occurrences of actual bodies 

 of limestone in place are, however, extremely rare. Those observed are — 



1. At the extreme western edge of Fryer Hill, as shown in the Colo- 

 rado Chief and some of the adjoining prospect shafts, where it is struck 

 directly beneath the Wash and apparently i-ests immediateh' upon the Part- 

 ing Quartzite, with no intermediate body of White Porphyry. The outlines 

 of this body could not, of necessity, be very definitely obtained, but it is 

 probably of considerable extent and evidently represents the wedge-shaped 

 portion separated by the cross-cutting sheet of White Porpliyry. It is here 

 a dark-blue, granular limestone, frequently somewhat impregnated with iron. 



2. A large body of lime-sand occurs in the western portion of the Chrys- 

 olite, south of Vulture No. 2, adjoining the lower iron body. 



3. A fragment of Blue Limestone is found below the main iron body, 

 included in the porphyry, in the second western drift south of Vulture No. 3 

 shaft (see Section F, Atlas Sheet XXXIII). 



MON XII 29 



