446 J. M. BOUTWELL 
leads Dr. Girty to suggest the correlation of this formation with the 
Bellerophon limestone in the Uintas. With regard to the position of 
the ore-bearing limestones of this formation in comparison with that of 
others in the Utah mining camps, they appear to be somewhat higher 
than the Highland Boy, Commercial, and Jordan limestones at Bing- 
ham (upper portion of the Weber quartzite); higher than the Great 
Blue limestone at Mercur (the Wasatch, Mississippian, or lower 
Carboniferous); higher than the Eureka and Godiva limestones at 
Tintic (Mississippian); and higher than the great limestone of Emma 
Hill at Alta in middle Cottonwood Canyon (Mississippian or lower 
Carboniferous). Thus the Park City formation is much younger 
than any of the limestones in Utah which have been found to bear 
ore bodies, except those at Bingham, and it is believed to be next 
younger than the Bingham formation. 
No unconformity was observed with either the underlying Ontario 
quartzite or the overlying shale, or between members within the forma- 
tion. Accordingly it would seem that sedimentation proceeded un- 
broken from Mississippian time on through that period of the Pennsy]l- 
vanian represented by the Park City formation. 
WOODSIDE SHALE 
Name.—The Woodside shale is named after Woodside Gulch, 
as the best exposed section of these sediments in the district is at the 
head of this gulch, on the slope which overlooks the Silver King plant 
from the west. 
Character.—This great formation is a lithologic unit, being com- 
posed from bottom to top, without significant exception, of fine- 
grained, dark-red shale. A shaly parting sometimes gives way to. 
very thin laminations, but the general homogeneous lithologic char- 
acter is maintained with wonderful uniformity. In rare exceptions 
a slight increase in coarseness of texture produces a fine grained sand- 
stone, or variations in color result in buff, brown, and greenish-gray 
shales; but such variations are extremely limited in number and extent. 
The characteristic topography which has developed on such a 
lithologically homogeneous formation is a full, even, uninterrupted 
slope. This is commonly densely overgrown with rank grasses, shrubs 
and aspen. 
