1998 Report
NOVEMBER 1998 - Potential Production Areas of the Deer Trail Mine
Piute County, Utah
The 3400 Area [ return
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Near-term production from the PTH haulage level can come from several locations.
The only place in the mine at present that has any proven reserves is in the 3400
area. A 30,000-ton block of proven and probable ore is located between the 200
level and the mineralized drill intercept of hole number DT-1. This block can
be enlarged by drilling several offsetting holes from the DT-1 and continuing
until the block has been completely defined. This particular block could possibly
contain over 200,000 tons. Also, a large resource of approximately 660,000 tons
of mineralization is estimated to be contained in the Redwall-Wet Fissure zone
of the 3400 area.
It is conceivable and very likely that the mineralization contained within
the Calleville formation and the Wet Fissure zone last mined from the 3400 area
will extend on a 25 to 30 degree easterly dip to near the surface. This target
should be considered a high priority target in that minerals could be accessed
from the surface via a new opening on patented claims. The length of this access
to the PTH tunnel is approximately 1800 feet.
Several mineralized horizons are present at the 3400 area on the PTH tunnel
level. These horizons are thin replacement deposits that yielded some production
in the past. These are associated with the Wet Fissure mineralized zone. The size
of these replacements encountered will not develop into large ore bodies due to
the nature of the stratigraphic boundaries by which they are contained. However,
small-scale selective mining of these areas could yield very near-term production.
The main target of the 3400 area is the Redwall formation along the mineralized
Wet Fissure zone some 400 feet below the PTH tunnel level. The Redwall formation
does not outcrop at the surface within the vicinity of the Deer Trail property,
but could be drill intercepted both from underground and from the surface.
Once sufficient ore has been defined in the 3400 area, a mining plan should
be designed to extract the mineralization in the most cost-effective way possible.
Achieving a cost effective method sometimes requires large capital expenditures
in order to develop the ore bodies for production. However, once the development
work has been accomplished, mining of the ore can be done efficiently and inexpensively,
thus increasing the profit-per-ton of ore mined. All up-front capital cost that
will be expended to develop the ore bodies can be quickly recovered once production
begins.
In order to get to this stage of prodution, several factors must be considered.
One, how much production is needed to satisfy current management priorities. Two,
how much capital can be budgeted at the present time to move forward. Three, in
what time frame is production expected. Understandably, to move from the present
state of affairs at the property, more exploration work is required to define
enough ore to begin even on a small scale.
The present proven and probable block of ore at the 3400 area can be developed
within a relative short amount of time. As stated above, this ore block contains
presently 30,000 tons. Daily tonnage from this body is estimated at approximately
50 to 100 tons per day depending on the thickness of the ore. It will be necessary
to access the 200 level of the 3400 area to gain optimum advantage of mining this
ore body. This can be done through the existing workings and installing a raise
with an ore skip, or it can be accessed by developing a decline to the 200 level.
However, if the ore body is consistent along the trend of the Wet Fissure to the
east up dip, then it would be conceivable to access the deposit by driving a new
drift from the PTH level east until the mineralized horizon is encountered and
mining then could be directed at producing on the up dip portion of the deposit
from that point.
The 8600 Area [ return
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De-watering the 286 should be a high priority in developing the 8600 area of
the mine. Ore is reported to be in the faces of the lower stopes and access can
be made via the 286. As explained before, the water must be drained into the caverns
south towards the portal of the PTH tunnel from the 8600 area. Once the 286 is
pumped out and fresh air supply installed, the area can then be developed and
an evaluation of the mineralization be made. Rehabilitation of the workings should
commence once all is made safe for entry.
The present winze should be extended another 100 to 125 feet and a drift from
the bottom of the winze should be designed to penetrate below the mineralized
areas that were last worked and a sense of raises put in to extract the overlying
ore.
The down dip potential of the 8600 area is very good and it is recommended
that further work to outline the resource be undertaken. The resource is estimated
to be in the range of one million tons (Noranda Exploration 1983). The ore is
intimately associated with the Red Fissure and the Deer Trail anticline; however,
there is little doubt that other mineralized structures exist within Deer Trail
Mountain and within close proximity to the Red Fissure zone. Development of this
resource would be highly beneficial to the operation and to Unico.
The area of the 18 North, just east of the PTH tunnel, should also be developed
further. The up dip potential of the Red Fissure zone within the Toroweap formation
could contain significant near-term mineralization. Also, wellplaced drill holes
could intercept mineralization in the underlying Calleville formation, which could
be developed both up and down dip of the Calleville horizon.
One other area of interest that should be explored some time in the future,
is the area approximately 800 to 1000 feet south of the 8600 area winze. At that
point several mineralized N50 to 60E structures were encountered in the PTH tunnel.
They are highly siliceous and contain noticeable copper staining which is very
similar to the mineralization encountered in portions of the 18 Drift Fault and
the Wet Fissure. Both the Calleville and Toroweap formations should be intercepted
by these mineralized structures creating a highly prospective zone of manto mineralization.
This target is completely untested.
Conclusion [ return
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After reviewing the data and several site visits, it is my opinion that there
is very great potential at the Deer Trail Mine. The mineralization is very similar
in nature to that found in the near by Park City and Tintic Mining districts in
Utah. These districts have produced well over a billion dollars worth of silver,
lead, zinc, copper and gold. The Deer Trail Mine once properly developed has the
potential to rival these districts. It is recommended that the areas mentioned
should be developed. The resources and mining plans outlined are designed for
both the near and long term production possibilities. |
