Figure 26. Chloritoid crystals (indicated by arrows)
grown at angles to the stylolite and white mica foliation
in fine grained quartzite of the Yanks Peak Formation on
Roundtop Mountain.

Figure 27. Spaced cleavage in micaceous quartzite of
the Yankee Belle Formation near Middle Mountain. (GSC
191024)

Stylolites rarely attain amplitudes greater than 3 mm and
are most often perpendicular to bedding. Locally there
is a spaced parting at angles to bedding. An example of
the mobility of the Mural Formation carbonate is shown
in Figure 28 where archaeocyathids are flattened along
a finely spaced cleavage.

The cleavage is pervasive throughout all pelite of the
section. It is predominantly of the smooth closely spaced
type of Powell (1979). Rarely is the secondary mica suf-
ficiently pervasive to produce a continuous cleavage. In
relation to rock classification the pelite cleavage varies
from slaty to phyllitic. Nowhere within the mapped area
are the rocks actually schists.

Figure 28. Stretched archaeocyathid cross-section in
Mural Formation limestone at the headwaters of

Sunshine Creek.

Figure 29. Open and tight folds in Yankee Belle Forma- .
tion micaceous quartzite near Middle Mountain. The tight
fold is adjacent to a reverse fault, fold side up. The white
rectangular patch at the bottom of the photograph is a
notebook for scale. (GSC 191023)

Folds

Fold axes generally plunge between 10 and 30° to the
northwest. Folds are relatively open on a large scale form-
ing broad asymmetrical anticlines and synclines such as
those in the Black Stuart and Kimball Mountain areas.
Outcrop scale folds are open to isoclinal, generally having
interlimb angles of between 35 and 70°. Similar to the
macroscopic folds, they are asymmetric and westward-
verging. The steep limbs may be overturned to the west
and are frequently offset by east-dipping reverse and
thrust faults. Their geometric classification ranges from
concentric to similar, commonly being of class Ic (see
Ramsay, 1967, p. 365-366). Pictures of some of the fold
types can be found in the publications of Sutherland
Brown (1957, Plates VIB and VIIB) and Holland (1954,

4]