Slot canyons are narrow, steep-walled canyons much deeper than
they are wide. Most slot canyons cut through sandstone or limestone
and are usually found in arid environments where there is little
soil to absorb water. In these conditions flash floods can develop
after a heavy rain, flowing downhill into cracks with tremendous
erosive power, gouging out walls and deepening the floor with
successive floods. Some of the most spectacular slot canyons occur
in the American Southwest. The following photo is from the famous
Antelope Canyon in Arizona.
The Tranquille River in Lac Du Bois Provincial Park is also home
to two impressive slot canyons. Unlike canyons in the American
Southwest, these slot canyons cut through volcanic rock and they
are likely not the result of flash floods. Water is still the
erosive agent, but the erosion process was probably more gradual,
with the canyons channeling water in the past from melting glaciers
and functioning as part of the Tranquille River drainage today.
If you’re lucky, standing on the river bank between the
two slot canyons you might spot the resident dippers searching the
water for aquatic insects. This peaceful scene belies a violent
geological past. Approximately 200 million years ago plate
tectonics slammed ancient islands and chunks of the Pacific Ocean
floor against the North American continent, forming mountains and
creating land where there was once only water. Two major volcanic
periods, about 150 and 50 million years ago, resulted in lava
pouring over the landscape, forming the Red Plateau, Opax Mountain,
Wheeler Mountain and the high parts of Mara Mountain. As recently
as 10 million years ago fingers of lava were spreading from the Red
Plateau to the east. Tectonic pressure caused a series of complex
faults to form the Tranquille River canyon, and these faults were
gouged and widened by successive glacial events that ended
approximately 10 thousand years ago.
The coordinates bring you to a river bank between two slot
canyons (see waypoints and map). From the pull-out, walk NE
downhill until you meet a well-established game/cattle trail.
Follow this trail south until you come to the south side of a small
ravine and head east. At the “Path to River” waypoint
(also the Dark Tower cache), follow the defined game trail to the
river. Dogs should be leashed and children watched closely as you
near the “Path to River” waypoint because the top of
the lower slot canyon has grass growing along the edge and the
ground drops away suddenly. The trail doesn’t go near this
edge but if you want to look into the lower canyon use extreme
caution and don’t trust the rocks. For obvious reasons,
don’t attempt this cache in icy conditions, and keep an eye
out for ticks. This is a strenuous hike on steep ground. Although
it is close to the Red Lake Road, this is a wild and rugged area
that it is not for everyone.
To complete this geocache, cachers are asked to:
1. Take a photograph with a GPS in the forefront, showing the
lower end of the upstream slot canyon (optional).
2. Visually estimate how far you can see into the upstream slot
canyon before it curves from sight.
3. Examine the rocks forming the river bed in the upstream
canyon. Did these come from the canyon walls?
4. Speculate briefly on why the slot canyons are so narrow at
this point compared to the broader canyons upstream by Watching
Creek (optional bonus points).
Send your answers to the cache owner before posting, and
don’t include your answers when logging this cache.
Sources:
British Columbia, A Natural History. 2004. Richard and Sydney
Cannings
Geology and Tectonic Setting of the Kamloops group,
South-central British Columbia. 1981. Thomas Ewing. (Thesis
available at: https://circle.ubc.ca/handle/2429/30328).
Slot Canyons: What are they?
http://www.summitpost.org/technical-slot-canyons-of-the-colorado-plateau/178925