Program, Abstracts, and Guidebooks - University of Minnesota Duluth

-bU-
STOP 2b Road cut, west side of Highway 590, 250 feet south of junction
and 500 feet south of stop 2a.
UPPER CHERT-CARBONATE EAGlES (FIG. 2).
Orange—brown weathered, banded chert—carbonate is inter—
bedded with tuffaceous shale.
18.3 Entrance to kakabeka Falls Park. Proceed over old bridge to
parking lot by Greenmantle restaurant, thence by foot to
falls rim.
STOP .3 UPPER TIJFFAGEOUS SHALE SUBHEMER (FIG. 2)
Kakabeka Falls drop 128 feet intp a gorge formed in
fissile, thinly bedded upper tuffaceous shale subinember
(Goodwin, 1956).
A more resistant, massive two—foot bed of thinly banded
chevt—carbonate caps the escarpment.
18.7 Access road to Ontario Hydro station. Turn right just before
the Kakabeka Falls motel. Proceed to the parking lot by the
station, thence by foot to the west side of the plant, via a
cat—walk over the penstock pipes. Follow the riverbank for
approximately 600 feet to the spiliway cut. Beware of poison
ivy.
Be advised that permission to trespass the Hydro property
must be obtained from the plant supervisor. The spiliway
serves as a safety valve to bleed-off excess water in the
event of generator failure at the power station.
STOP 4 UPPER TUFFACEOUS SHALE SUBMENBER (FIG. 2)
The best section of upper tuffaceous shale submember is
exposed at this locality. Pyrite—bearing chert of the upper
algal chert submember occurs at the base of the section; it
is overlain by shale containing pyrite nodules and calcareous
concretions, interbedded shale and tuff and a tap of thinly
bedded upper chert—carbonate.
One of the best exposures of "mud ball tuff" in the shale
occurs near the bottom ofthe section; the tuff is formed of
closely packed ellipsoidal structures, elongated along the
bedding. Individual ellipsoids contain small, angular fragments
of uniform size, grouped concentrically around a larger
shard fragment:. The remainder of the materihl comprising the
beds consists of fragments of lava in a groundmass of a green,
clay material. (Goodwin, 1956)