Schist and quartzite, Smokey Mountain Ski Hill EarthCache
Schist and quartzite, Smokey Mountain Ski Hill
-
Difficulty:
-
-
Terrain:
-
Size: 
(not chosen)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
Take the road to Smokey Mountain ski hill on the north side
of
Labrador City, drive 3.2 km to the end of the road and park.
For
safety and information you could check in with the manager
before
climbing the hill. The best exposures can be seen under the
farthest north of the ski tows.
Warning! The top section of the hill is very
steep.
For an easier route to the very
top, follow the service road
around where it crosses the tow line below the steepest part of
the
hill. The coordinates to the entrance to the road are
N 52º 58.593 W066º 55.187.
The lower slope exposures are made of quartz_feldspar
schist,
which also contains muscovite, kyanite, garnet, staurolite
and biotite. Some boulders in the debris from close by
consist
almost entirely of biotite although this material does not
outcrop.
These rock types result from metamorphism of sandstone and
shale during the Grenvillian Orogeny.
Farther up the hill, and on up to the top are large
exposures
of white quartzite. This highly resistant rock can be seen
on all of the hilltops around, where it has been smoothed
and scoured by glacial action. You can feel with your hand
the smooth grooves left by the ice. On the way
to the top, where the main track is joined
by another track leading downhill to the right, leave
the track and walk a few hundred metres
up the low hill to the northwest. This hill
is underlain by oxide iron formation here composed of
hematite_magnetite_quartz schist, similar to the material
being
mined by Iron Ore Company of Canada. You can see
folded banding, in which the colours indicate different
amounts of quartz. The iron formation overlies the white
quartzite,
which caps the surrounding hills. A few hundred
metres farther northwest, across the small valley, is an
outcrop of gabbro on a low hill. The gabbro intruded the
iron
formation in Middle Proterozoic time. It is composed of
feldspar
and pyroxene, with some olivine, ilmenite, biotite and
apatite.
At the top of the ski hill, there is an excellent
view of the two towns to the south, and of open pit mines
to the north. Tailings from the processing of the iron ore are
being
deposited behind a dam in the lake to the east. The mining
company is gradually revegetating the tailings; the green,
grassed portion contrasts with the grey, newly deposited
tailings.
To log this Earthcache please take a picture of yourself or
part
of yourself with your GPS and the Ski Hill in the
background.
Also email the owner telling:
1) what is the general direction of the grooves in the
white quartzite at the top of the hill,
2)what you estimate the elevation to be at the base of the hill
and
3) the elevation at the top.
Additional Hints
(No hints available.)