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flat is apparently an upstream continuation of the bench, the part between
having been eroded away and the old pay-streak largely destroyed by the
effects of glaciation.

A curious fact, and one that has often been commented on by the
local miners, is that the tributaries of Lightning creek on the south side
were rich in gold, whereas those on the north side contained little or no
gold. It has also frequently been noted that in the district as a whole
the streams flowing north, northeast, and northwest contain much more
gold than those flowing in the opposite directions. There are, of course, excep-
tions. Keithley creek, a rich gold-bearing stream, flows southeast and
there are streams that flow north in the gold belt, yet carry little or no gold.
The placer gold on the creeks was derived by weathering and erosion
of the vein gold deposits in the bedrock and where these are abundant the
creeks in the vicinity are or were rich in gold, so that it may be largely
accidental that the northward flowing streams are the richest. Neverthe-
less the rule holds good in so many cases that there is probably some good
reason why this is so. One theory has been suggested to the writer by
Harry Jones, who has lived on Lightning creek since 1863, except for a
few years absence, and is one of the ablest of the mining men in the district.
He suggests that the gold was partly derived from the gold-bearing veins
in the bedrock by erosion by glaciers; that the valley glaciers were much
better developed on the northerly than on the southerly slopes—being less
exposed to the sun—and, therefore, accomplished more erosion; and that
the gold was concentrated in the northward-trending valleys and was
later buried by slides from the valley sides and by lake deposits in the
slide-dammed valleys. There are certain objections, however, to this
theory, which has been pretty widely accepted by the prospectors. The
conception of huge rock and mud slides from the mountain sides is one
that has persisted since the early days. There are numerous slides in the
district, especially on some of the steep-sided creeks, such as lower Lightning
creek, but they are not nearly so common as is generally supposed, and the
valley filling in many places consists of morainic materials, as below
Stanley, deposited at the end of a glacier in the valley bottom and of boulder
clay deposited beneath the ice or from the ice when it melted. The strati-
fied glacial silt (slum) was deposited in water bodies which may have been
dammed by ice tongues or moraines in the valley bottom and possibly in
places (as Jones suggests) by slides, and the glacial gravels forming a con-
siderable part of the valley filling were deposited from streams flowing
from the ice. There is no evidence that the moraines and extensive sheets
of boulder clay in some of the valley bottoms were formed from slides.
The gold in the bottom of the channel must have been deposited before
the valley was filled with the glacial drift, except perhaps such parts
as may have been deposited along with the glacial gravels, and where
these extend down to bedrock, may have become concentrated by
working down through the gravels. It is trite that the northward-
flowing valley glaciers were the most active ones, but near the heads
of the creeks, for example in the upper parts of Williams, Antler, and
Jack of Clubs, where erosion by valley glaciers was much greater
than lower down on the streams, there is no gold. Evidence of
this greater erosion is supplied by the cirques and broad, flat-bottomed

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