Coromoto Minerals
The 2004 Season at Mt. Mica
---- May -----
A view inside one of the upper chambers of Pocket 7 (MM7-04)
Encouraged by our modest finds in April, we resumed mining the pegmatite
with re-newed vigor in May. As we worked further down dip we had to deal
with an increasingly thick layer of schist. The schist was now 8-10'
thick in the western corner in which we were working. I know various observers
were puzzled why were subjecting ourselves to this unnecessary work when
we could have easily gone to eastern end
of the pit. There we would have only to deal with 3 to 4' of overburden.
In addition, both Merrill and Perham had had some success there.
The plan that had been in my mind from the beginning was to come into the
pit from the western end, mine to the existing high wall taking the pegmatite
left by Plumbago in the '90s, and then turn eastward up strike. Once we
had completed this exercise, we would have a complete fresh exposure of
the pegmatite along strike from contact to contact. Based on our observations
accumulated as we completed this process, we would be in a good position
to decide where to proceed down dip along the 300'+ exposure.
( In the image the lower 8' of schist is clearly visible on the right. The remnants of the 1979 Dagenais pocket is the water puddle at the far left.) While I had been back in Florida at the end of April, Richard, with the help of Mike Robbins, another miner, drilled the remaining schist in preparation for removal. While doing so, they discovered that ,although the schist was consistently 8-10 feet thick, near the center of the overburden the schist suddenly thinned to only 4'. This meant the pegmatite swelled beneath. Our experience had taught us that these swellings portended a sizable pocket. In the image above, the area that had thinned out was immediately behind the bucket laying on its side. Adding credence to the idea was the rusty area below the bucket. I did not dare to believe, though, that such a pocket might exist. Mining requires near blind optimism. It is best managed with a prophylactic dose of doubt and skepticism. In addition to mining in May, we where on tap to describe our finds found last year in a talk at the Maine Mineral Symposium that ran from May 5-7. Richard and I spent a full day mining on the 5th. That day we encountered pocket number 4 of the season. Cleaning this pocket out took us into the late afternoon and cut into the time I had set aside to prepare for my talk and arrange our exhibit case. We did find our first gem green tourmaline though. This became our 'pocket piece' at the symposium and was soon to pale in comparison to later finds. Returning on May 8th a little battle scarred but nonetheless relieved
to have the symposium behind us, we again set to work mining the pegmatite.
We decided just to blast a couple of holes drilled into the prepared schist
overburden. There was opinion that our 'swelling' may have just been a
stringer in the schist. This was a possibility, but I did not think so.
Shooting just these holes peeled off some of the schist and little of the
pegmatite below. It was now clear this was no stringer. In our operation
Richard operates
the excavator and I drive the dump truck and operate the bulldozer. So
while Richard was loading the schist muck into the truck, I climbed
down onto the pegmatite and started cleaning off some of the loose material.
There were several small vugs in albite very near the contact. Working
these a little exposed some small green tourmalines very similar to the
ones we found above pocket 3 (MM3-04). As we worked these vugs, they began
to enlarge and merge into two sizable chambers. Pocket number 7 was beginning
to take shape. The tourmaline was now becoming increasingly abundant. Many
of the deep green crystals coming out had nice rhombohedral terminations.
This differed from the mostly basal terminations we had been finding. (In
this view of the working face one can clearly see the pegmatite rising
into schist by comparing to the picture above. The beginning of
pocket 7 is the dark triangular patch near the center of the image.)
While working the pocket, Mary could feel a large pointy mass in the mud.
Clearing off enough to loosen it, she pulled out a very large opaque green
tourmaline but exceedingly well formed. This pocket was getting interesting.
We were now taking out tourmaline after tourmaline. (Mary's tourmaline
is the large one on the left in the image below)
A group of tourmalines from the upper portion of pocket 7 |