These cliffs are situated across the
Thompson River from Hwy 1 just north east of Lytton
BC. They are located in
the Skihist Ecological Reserve which is not accessible by car and
you MAY
NOT enter the reserve without a permit. The
cache location gives you a view of the cliffs across the
Thompson River where you
will be able to park safely and take some photographs.
For safety purposes, this cache is available to traffic
heading towards Lytton.
For better viewing you may want to visit
the
Behold!
Marble Canyon. This
is a tricky spot to stop at if you are driving in an RV, so use the
above coordinates to safely stop and take the photo. You may
also be able see a portion of the cliff from the Skihist
Provincial Parkday use
area.
The
Skihist Cliffs in the fall looking over the Thompson from the
Behold! Marble Canyon Cache
The cliffs are located in the physiogeological region called the
Intermontane Belt in BC. Geologists estimate that the rocks are 225
million years old, and are found in the Mount Lytton
complex of
BC. The
cliffs are composed of gneiss. Gniess is a metamorphic rock
that is formed when existing rock is exposed to high pressure and
temperatures (for
instance by being buried deeply under younger rocks, or during
tectonic processes) which
alters its composition and usually results in a harder more compact
rock. The
Skihist cliffs are a spectacular example of banded
gneiss. The
light coloured bands of rock are mostly quartz and feldspar, and
the thin dark bands are composed of amphibolite. The pressure can also
result in the layers being contorted into wavy
folds. This
is called compositional banding and there are visible examples of
this on the cliffs.
“Because
of the kinds of minerals and degree of alteration present,
geologists estimate the rocks of the Mount Lytton complex were
likely metamorphosed at a depth of 15 km below the surface. These
rocks were then brought back to the surface through the processes
of uplift and erosion.
The gneiss is crosscut in places by irregular brown dikes which may
be feeders to the overlying, younger, Spences Bridge Group
volcanics. The dikes are remnants of the route the volcanic magma
took through these rocks to reach the surface. The Spences Bridge
Group volcanics are not visible on the cliff, but can be seen in
the Thompson River valley north of the village of Spences
Bridge.” - Christine
McPhee, Student
Librarian,Natural Resources Canada Library
View of the cliffs from the Earthcache location
in the spring time.
Some beautiful photographs of the cliffs are in the
book
Manufactured Landscapes: The Photographs of Edward
Burtynsky.
To log
this earthcache you must email the answers to the first two
questions and post a picture with your cache log.
1.
Use your GPS to estimate the height of the
cliffs.
2. What is an example of erosion at the site that you can see
that would expose the cliffs?
3. Why do you think the bands of gneiss are different
colours?
Optional: Take a photo of the site with your GPS to include
with your log, you may also be in the photo.
Congratulations Puddle Duck 21 and High
Maintenance for the FTD - First To Discover