LOR

Jeake

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stages in the pre-glacial downcutting of the creek.

The country was glaciated in two periods, separated by

an interglacial stage. Glaciation in neither was suf-

ficiently destructive to disperse the placer-gold accu- mulations.

On Wheaton Creek a belt of serpentine 3 miles wide is flanked by slate, argillite, limestone and andesitic Vor eanics. The serpentine includes remnants of the sediment- ary cover and is intruded by diorite and quartz-diorite.

There are many quartz stringers and veins in the slate and schist. Some are mineralized with pyrite, but none are known to be gold-bearing.

From 1935 to 1939, the total production of crude gold has been 4852 ounces, valued at $140,708.00. This came mainly from two leases on Wheaton Creek and one on Alice Shea Creek.

The placer-gold being mined on the Peacock lease lies be- low creek-level on flat-lying bedded clay which rests on the bed-rock of an interglacial channel. On Alice Shea Creek the gold is on bed-rock beneath a few feet of grav- cl inecheubotLom of the creek. “On the Miva lease

(No. 402) the gold is a recent concentration on bed-rock below creek-level in the lower canyon of Wheaton Creek.

The placer-gold on the Peacock lease did not migrate down- stream from a source on Alice Shea Creek. The difference in fineness of the gold strongly suggests that the placer concentrations came from different sources.

Most of the placer-gold is believed to have come from the erosion of auriferous quartz veins in the slate and schist. Some on Alice Shea Creek appears to have come from an auri- ferous pegmatite or feldspathic quartz vein. Some may have come from mineralization in serpentine, though no veins in serpentine have been seen.

On Wheaton Creek, where creek-grade and depth of gravel are favourable, the auriferous gravel is worked by boom- ing or ground-sluicing. On the Peacock lease the gravel below creek-level is excavated by a 7/8-yard drag-line shovel, and is washed in a moveable sluice-box. Any tail- ings that accumulate and block the sluice-box are stacked by a bull-dozer. On Alice Shea Creek the shallow gravel is shovelled by hand into a string of 12-inch sluice- boxes and the bed-rock carefully cleaned.

The hypothesis of the physiographic history, as developed

from the detail on Wheaton Creek, should be useful in dir- ecting further prospecting on Wheaton and on other creeks

tributary to the head of the Turnagain River.

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