GOLD AND SILVER. 
In addition to the papers here included, which represent the results 
of recent work by the Survey in important precious metal mining 
districts, other reports bearing incidentally on the subject of gold and 
silver will be found Under the head of "Copper," on pages 105 to 186. 
PROGRESS REPORT ON THE PARK CITY MINING DISTRICT, 
UTAH." 
By J. M. Boutwell. 
INTRODUCTION. 
Field work. — During the field season of 1901 two detailed topo- 
graphic maps of portions of the Park City district were prepared by 
this Survey under the direction of E. M. Douglas, geographer in 
charge, by Pearson Chapman and J. F. McBeth. The general map, 
showing an area of approximately 32^ square miles on the scale of 3 
inches to 1 mile, embraces the general area in Park City through 
which mining operations have been conducted; and the other, on a 
scale of 1 inch to 1,000 feet, or 5.2 inches to a mile, includes only that 
portion of this area which lies in immediate proximity to the largest 
producing mines. 
Late in the field season of 1902 a detailed study of the areal and 
economic geology of the Park City mining district was undertaken by 
J. D. Irving and J. M. Boutwell, under the supervision of S. F. 
Emmons, geologist in charge of metalliferous deposits, and was con- 
tinued into December of that year. This was the first systematic 
geological work in this region since Emmons mapped the broad fea- 
tures of the range in 1869, while engaged in the " Geological Explora- 
tions of the Fortieth Parallel," under the late Clarence King, and was 
the first detailed geological examination of an extended area in the 
Wasatch Range. Before detailed work in the area under survey 
could be advantageously undertaken a general knowledge of the 
geological history of this portion of the range and the establish- 
ment of the geological succession were required. Accordingly, the 
general geology of the region surrounding the special field of work, 
including the main divide of the Wasatch Range to the west, its 
"This sketch is merely a preliminary statement indicative of progress. A complete report 
will be published after a detailed survey has been completed. 
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