Purple
Lorrain
Quartzite,
Proterozoic,
Huronian
Supergroup:
2.2-2.5
billion
years
old;
Highway
17,
Desbarats,
Near
Sault
Ste
Marie
Quartzite
is
a
metamorphic
rock,
meaning
that
it
was
formed
from
a
prior
rock,
which
was
modified
by
heat,
pressure
or
both.
It
was
formed
from
a
pure,
white
sandstone,
which
was
almost
entirely
quartz,
subjected
to
heat
and
pressure,
which
fused
the
quartz
grains.
The
purplish-reddish
colour
has
to
do
with
Iron
formation
due
to
oxygen
buildup
during
the
Huronian,
with
the
largest
amount
present
at
the
top.
Here
we
are
with
the
crane
picking
up
the
Purple
Quartzite
and
its
sister
rock
(rock
with
glacial
striae
in
the
garden).
The
other
rock
is
the
first
we
collected
-
Jasper
Conglomerate.
Sam
Vales
is
directing
the
crane
operation.
