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series of parallel dips meant a corresponding thickness of strata. The
figures he obtained for stratigraphical thickness were so great that he deemed
it advisable to divide them by three to six to arrive at a more reasonable
result. In the detailed field work on the structure sections carried out in
connexion with the present report, abundant testimony was obtained
regarding the lack of coincidence of cleavage and bedding planes in the
schistose and slaty rocks (Plate XII). Many localities were seen in which
the cleavage planes of these rocks maintained a northeasterly dip on the
northeastern limb of the anticlinorium, whereas the bedding planes were
observed to be intimately crenulated, but to have in general a nearly
horizontal attitude (Plate XII A). In other words, the flow cleavage planes
were seen to be parallel to the axial planes of the drag folds (Plate XII
A, C). Sufficient evidence of this relationship and structure was obtained
to prove that a very decided repetition of beds in the Cariboo series exists—
not such, however, as might be produced by strike faulting (although that
also occurs), but a repetition of an intimate character in which each bed is
repeated several times as a result of closely packed drag folds. Unfortu-
nately the field evidence provided no factor by which to reduce the apparent
thickness in order to arrive at a true figure, but it can safely be said that
Bowman’s factor of three to six as a suitable divisor is not far from correct.
The thickness of the exposed Richfield formation, as estimated from the
geological structure sections, is not over 8,000 feet ; that of the Barkerville
formation not over 2,500 feet, and that of the Pleasant Valley formation
about 5,000 feet.

The intimate folding characteristic of the softer beds of the Cariboo
series is not developed even in the incompetent interbeds of indurated shale
of the Slide Mountain series. The deformation of this series was conse-
quently much less severe than that of the Cariboo series, although it is of
the same general character. Evidently there were two periods of folding—
the period of more intense folding being pre-Mississippian; that of less
intense folding being subsequent to the intrusion of the Mount Murray
sills. The beds of the Slide Mountain series do not seem to have been
repeated by close folding, so that the thickness exposed in Barkerville area,
may be read directly from the geological structure sections.

The Slide Mountain series with its upper formation of massive, thickly-
bedded limestone (as exposed along Spectacle lake, Bear river, and Swamp
river, to the east of Barkerville map-area) appears to lie in a synclinal
attitude between the Mount Agnes anticlinorium on the southwest and the
Cariboo Range anticlinorium on the northeast. Lack of knowledge con-
cerning the nature of the contact of this upper limestone with the rocks of
he Cariboo range prevents a more definite statement of these structural
relations.

Faulting

Three types of faults occur in the area:
Reverse faults of compression
Strike faults of tension
Normal cross-range faults of tension
Reverse Faults of Compression. As an incident of the folding of the
Cariboo series, thrust faults of small magnitude developed along the crests