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of some of the minor folds. The most striking evidence of this faulting
may be observed at the crest of the main anticline where it crosses mount
Agnes (See Geological structure section and Figure 5). Other faults of the
same type occur, but were either too difficult to locate or too small to map.

Strike Faults of Tension. Only one fault of this character was found in
the area. It extends from Ninemile lake to a point on the southwestern
slope of mount Guyet, but in no place was its outcrop observed. Its
location on the map is based on the relations of the adjacent formations to
one another. Its strike corresponds in general with that of the formations,
but its dip is inferred to be towards the southwest or opposite to the dip of
the formations. The character of this fault is brought out particularly well
on the geological map (No. 2046) by the areal relationship of the two belts
of the Barkerville formation, which coalesce on the southwestern slope of
mount Guyet. The faulting is believed to be normal and of the hinge or
rotary type; and the country southwest of the fault is believed to have
dropped relatively to that on the northeast. Owing to the overburden, no
details of the nature of this fault could be obtained. The actual displace-
ment along the plane of the fault, where the geological section line A-B
crosses it, is about 6,000 feet.

This hinge faulting was an aftermath or consequence of the formation
of the anticlinorium. It was completed before the initiation of the later
folding which involved the Slide Mountain series, since the sequel of
this later folding was the series of cross-range faults which crosses and
offsets the hinge fault.

Normal Cross-Range Faults of Tension. A very large number of
normal faults with trends varying from north 15 degrees to 40 degrees
east cross all the formations of the map-area. Their dips vary from north-
west to southeast, but are invariably steep. Eleven of the most prominent
of these faults are shown on the geological map. As stated above, they
appear to be a consequence of the second period of folding, and they
represent an attempt to re-establish the condition of stability which had
been upset by the folding. The rocks of the entire area are sliced by |
joints and faults with a northeasterly trend, so that after the elevation due
to folding was complete, the blocks of rock between the main faults settled
down against one another and produced the effect of block-faulting.

Two of the most outstanding of these faults are: the one which runs
down Grouse creek and across Antler creek; and the one which passes
through Cornish lake, Cornish creek, and Willow river. The last one causes
an apparent horizontal offset of about 4 miles. Neither of these faults
could be actually traced in the field, but their presence was determined
and located by the outlines of the faulted rocks.

Smaller faults belonging to this group can be easily detected on Slide
mountain, mount Murray, and mount Greenberry, where rock exposures
are good and where variety of strata lends itself to the actual observation
of offsets. Within the area of the Cariboo series it was very difficult to
determine the offsets, but a cross-jointing, parallel to, and correlated with,
use cross-range faults, occurs very prominently in the quartzites and
slates.