92 FAIRBANKS AND RAMPART QUADRANGLES. 
CHICAGO CREEK. 
Chicago Creek is a small rivulet flowing down the northern slope 
to Omega Creek about 2^ miles west of the mouth of Seattle Creek. 
Pay was reported to have been discovered near its mouth during 
the summer of 1904, and it was the intention to work it during the 
winter. 
THANKSGIVING CREEK. 
Thanksgiving Creek is a small tributary of Omega Creek, between 
4J and 5 miles west of Eureka Creek. It occupies a shallow, open 
depression in the southern slope of the ridge, on the north side of 
Baker Flats, and can hardly be said to have a valley in its lower part. 
It is almost dry in the summer and fall. Gold was discovered on it 
in February, 1903. The combined output of Omega and Thanks- 
giving creeks has been about $18,200. 
The bed rock is exposed only in the diggings, but where seen was 
a yellowish, somewhat schistose grit. The gravel varies in depth 
from 6 to 18 feet w T here the creek is worked, though it is said to be 
deeper farther downstream. It is composed of subangular pieces of 
quartzite, schistose grit, vein quartz, slate, and a small amount of 
monzonitic rock. The overlying muck is 1 to 4 feet in thickness. 
The gravel is peculiarly mixed with a sticky yellow clay, which in 
places seems to be half ice. In some of the deeper holes there is 10 feet 
of this mixed clay and ice. It can not be worked with wood fires, for 
when melted it runs down upon the fires and quenches them. In open 
cuts the sides when melted move together like a mass of yellow tar. In 
some of the holes the section is said to show 10 to 12 feet of finely 
mixed yellow clay and ice, of which 5 feet is fully half ice and below 
this there is 6 feet of subangular gravel. The pay streak varies in 
width from 25 to 45 feet, and is 1J to 9 feet thick. Gold is sometimes 
distributed through the yellow clay and colors always occur through 
the mixture of clay and ice. At one place where the pay is found 
through 7 feet of the ice-clay mixture, Avhen the mass is thawed the 
pay sinks to the lower 4 feet. If the clay is dried it is difficult to part 
the gold from it, and at one claim, on which open-cut work was pro- 
gressing, angular pieces of sheet iron like saw teeth were driven into 
the poles used in the sluice boxes to break up the clay. The iron pieces 
were left projecting about three- fourths of an inch, and 25 were used 
to a 6J-foot pole. The device is said to work well. 
The gold is generally rough and somewhat iron stained, but some 
of it is smooth, bright, and " shotty." Some " black sand " is said to 
be with it in the concentrates. K. H. Wright picked out 8.48 ounces 
of the smooth, bright gold, and the United States assay office at Se- 
attle gave it a value of $15.64 per ounce. In it there were 1.68 ounces 
of silver and 0.4 ounce of impurities; 32.03 ounces of the gold as it 
