FOLDS.

In the area the rocks, though considerably folded, generally have a westerly to
north-westerly strike with low to moderate north-easterly or south-westerly dips.
North, north-easterly, and easterly dips in the area lying north-east of Lightning Creek,
changing to south-westerly and southerly dips in the area lying south-west of Lightning
Creek, indicate that the axis of the regional anticline trends about north 50 degrees
west and more or less coincides with the course of Lightning Creek between the junction
of Houseman Creek and the mouth of Anderson Creek. This is about 2 miles south-
west of its previously mapped position between Mounts Amador and Nelson. Bowman,
on his detailed map of Lightning Creek,* indicated a minor anticlinal axis in a similar
position, but mapped the major axis as lying to the north-east. There is no evidence in
the Stanley area of the position of the major axis as formerly mapped.

In detail, the position of the axis is indicated as lying between the south-westerly
dipping beds on Anderson Creek and the north-easterly dipping beds on Davis Creek,
and by the swinging of southerly dipping beds on Lightning Creek up-stream from
Stanley to easterly and north-easterly dipping beds along Dry Gulch, Perkins Creek,
and on Burns Mountain.

The structural lines on the accompanying map show an area of westerly striking
and gently north-dipping rocks extending from Coulter Creek through the Slough Creek
benches and up Devils Lake Creek and Burns Creek to Lot 10448c. Along Devils Lake
Creek between Hong’s siphon and the Public Works camp the rocks lie in an anticlinal
nose pitching eastward at about 25 degrees.

In the area extending from the ridge west of the Public Works camp, along Oregon
Gulch, Davis Creek, and Perkins Creek to Burns Mountain the rocks strike northerly,
varying a few degrees either west or east, and dip at low to moderate angles eastward.
There appears to be a minor swing in the formations on Burns Mountain from north-
westerly striking rocks around the Perkins veins to northerly striking rocks near the
summit.

The relation between the northerly striking and easterly dipping beds on Burns
Mountain and the westerly striking and northerly dipping beds on Burns Creek is
unknown. Moreover, the relation of the panel of northerly striking and easterly
dipping beds west of the Public Works camp to the easterly pitching anticline to the
east is unknown.

The north-westerly striking and south-westerly dipping beds on Anderson Creek
swing around an anticlinal nose whose axial plane, west of Last Chance Creek, strikes
about north 25 degrees east.

Along Lightning Creek between Stanley and Houseman Creek the beds for the
most part are westerly striking and southerly dipping, but have local swings and
contortions between Grub Gulch and Butcher Bench.

Drag-folds are a common feature of the rocks. For the most part the amplitudes
of the folds observed are no more than a few tens of feet. It is thought that most of
the drag-folds are related to the older deformation and some to the younger, but it was
not always possible to distinguish between the two. The extremely variable direction
and pitch of the drag-folds probably results from their being of two different ages and
also reflects the extremely unsymmetric nature of the folding (see Plate IV B).

On lower Coulter Creek, the Slough Creek benches, and on the west side of lower
Devils Lake Creek the pitch of drag-fold axes is about 10 degrees west; in the old
Burns Creek placer pit, 10 degrees east; along the road in Devils Canyon east of the
Public Works camp, from 10 to 25 degrees east; on Burns Mountain, 10 to 20 degrees
south; on Van Winkle Creek, horizontal to 5 degrees east; in Spruce Canyon, 15
degrees south-east; and on Houseman Creek, 5 degrees south-east.

There is no direct evidence in the Stanley area regarding the ages of the two
periods of deformation. The older folding and accompanying regional metamorphism

* Geol. Surv., Canada, Map No. 365, 1895.
2