148 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
pyrite, are found in the gulches. These are of such size as to indicate 
that the ore bodies from which they came must be at least 6 inches 
wide. The ore is of so low grade, however, assaying but six-tenths 
of 1 per cent, that the deposit is without value. This ore is supposed 
to be related to an intrusive contact between the greenstone and the 
limestone about the heads of the gullies in which the ore is found. 
On Camp Creek, an eastern tributary of the Nabesna, about 15 
miles below the glacier and about 3 miles above the mouth of Cooper 
Creek, Mr. Alfred B. lies reports a vein of chalcocite from (5 inches to 
2 feet in thickness. Both the limestone and the greenstone are pres- 
ent in this region, and it is probable that the ore occurs in association 
with them. 
Natives living on the Chisana (Upper Tanana) in 1002 had in then- 
possession a number of small copper nuggets, and one mass which 
weighs 35 to 40 pounds. These, they say, came from a small creek 
which (lows into the Chisana from the west at a point about 5 or G 
miles above the foot of the glacier. Occasionally the nuggets have 
adhering to them fragments of amygdaloidal greenstone and of calcite 
gangue. It is likely that they occur in the usual way, in association 
with the contact of the diabase and the Permian limestone. 
Prospectors, among whom may be mentioned Mr. D. K. Van Cleef, 
report the finding of numerous copper nuggets along the north base 
of the Nutzotin Mountains between the Upper White and the Chisana. 
Mr. Van Cleef reports also the probable existence of a sulphide vein 
in a canyon of 1 he middle White. 
Kletsan Creek, which drains the north base of Mount Natazhat, 
is a southern tributary of Upper White River. Native copper in 
placer form has been known in this region since Dr. Hayes a visited 
it in 1891, and it was probably a source of supply for the Indians long- 
before that. Mr. Alfred II. Brooks b in 1899 reported one nugget 8 or 
10 pounds in weight, and numerous other smaller pieces from this 
locality. In a search for the origin of the nuggets, Mr. Brooks found 
stringers of the native metal occurring in calcite veins in dioritic 
greenstones near the intrusive contact of the greenstone with Per- 
mian limestone. No other minerals except a superficial staining by 
malachite were observed. The character of the bed-rock geology and 
the finding of native copper in stream gravels led Mr. Brooks to infer 
that conditions similar to those at Kletsan Creek are likely to be 
found in the region between the Upper White and the Chisana. 
From these meager descriptions it will be realized that the search 
for valuable deposits in the field north of the Wrangell and Skolai 
Mountains has not thus far revealed any large ore masses, but as the 
search has been by no means exhaustive it is entirely possible that 
deposits of practical importance may be found in the future. 
"An expedition through the Yukon district: Nat. Geog Mag., Vol IV, pp. 117-162. 
'-A reconnaissance from Pyramid Harbor to Eagle City, Alaska: Twenty-first Ann. Rept. U. S. 
Geol. Survey, Pt. II, 1900, p 377 et. seq.. 
