PARI CITAV= MINING DISTRICT, UTAH 457 
the eastern side lies farther south than the western. In the same 
deformational sense the western member, especially that area of 
Weber quartzite lying east of Park City and that forming Bald Eagle 
Mountain, has moved eastward up this same fault plane, overriding 
geologically higher formations. As a result of this extensive over- 
thrust faulting, two formations, aggregating 2,000 feet in thick- 
ness, have been overridden until the Weber outcrops against the 
Thaynes formation. The economic importance of this discovery 
lies in the fact that the principal ore-bearing limestone of the district 
which had been believed hitherto to strike north from Park City and 
to disappear beneath the extrusives, in reality occurs immediately 
east of the settlement in an easily accessible locality. 
The principal zone of fissuring in this region trends across the 
central portion of the district in a northeast-southwest direction and 
dips steeply toward the northwest. It embraces the lodes which have 
afforded the valuable output from the Ontario, Daly, Daly West, 
and Daly Judge properties. The faulting on the main fissure of 
the system in its eastern extent, the Ontario, as measured in the vicinity 
of Ontario shaft No. 3, was relatively a downward movement of the 
north or hanging wall side, aggregating 330 feet. Correspondingly 
great dislocation occurred on the most important member of this 
system in its western part, the Daly-Daly West fissure, also on other 
members; and in certain instances a relative downward movement 
of the south or hanging wall side of south-dipping fissures is clearly 
shown. 
North of this zone members of the northwest-southeast system 
appear in a series known after its principal member, the Massachusetts 
fault. This may be best seen trending west-northwest and standing 
about vertical in the Daly Judge tunnel and at the Massachusetts 
shaft. Its structural importance lies in the fact that the north side 
has been moved along it relatively westward about 2,500 feet. Its 
economic importance arises from the fact that its recognition and 
solution answers the hitherto standing query as to the relation of the 
ore-bearing limestones of the Silver King and Daly West properties, 
respectively; namely, they are portions of the same formation—the 
Park City limestone. 
A similar result of these east-west ceils J is shown on the west side 
