CLIFF MINE
Phoenix, Keweenaw Co., MI
Cliff Mine dump
After
leaving the Central Mine, I drove to the Cliff Mine. It’s located on the west
side of Cliff Drive, which runs parallel to US 41 and intersects it at both ends.
The dump is near the north end of Cliff Drive. GPS coordinates are lat. 47 deg.
22.347’, lon. –88 deg. 18.747’. There’s a small stream running along the edge
of Cliff Drive, actually more of a drainage ditch. I wouldn’t suggest trying to
cross it in a passenger car, but trucks had no trouble. After crossing the
ditch there’s an area for parking, and another shallow stream (in the picture)
before the dump. We were asked not to drive across the stream, but it was
shallow enough to drive through.
This
is an old and well known mine. It was the first major producer in the copper
country, operating from 1835 to 1870. The dump is quite extensive, but has been
picked over.
There
is copper in leaf form running through the host rock, but the micro copper
crystals are found in vugs in prehnite. I picked up a lot of prehnite to break
up and leach with acid after returning home.
When I did so, I found a few good copper crystals, nice prehnite in
blocky prisms, quartz, pumpellyite, a few fairly good epidotes, and a couple of
chalcocites.
Although
the collecting wasn’t the best, it was an enjoyable afternoon. I spent some
time on the slopes of the dump talking with an old friend, Joe Heyman. Joe had
lived in the Houghton area, but had moved a few years ago to El Paso, Texas. He
had come back to the UP for a visit, timing it nicely to coincide with Keweenaw
Week.
On to the next field trip, the
Caledonia Mine