Promising Discovery of Gold on 1500 level
Work in the mine has been proceeding according to plan, with most of our efforts concentrated on removing and milling ore from the 2200 level and renovating the 1500 level. We are the first ones to explore the 1500 level north of the Tightner Shaft since 1965, when flood damage blocked the level.
On October 8, 1992, just as we cleared the major cave-in on the 1500 level, we discovered that quartz boulders fallen from the vein through which the level was driven contained at least 350 ounces of gold. This is our highest recovery in any two-day period since the start of the strike in January 1992.
This event has significance beyond its direct economic impact. As you can see from the map, the area of the mine north of the Tightner Shaft contains far fewer levels and workings than the area south of the Shaft. The nearest level to the 1500 at the point where we discovered the gold-bearing quartz is 500 feet above - there are no levels at all below. We have now tested the quartz vein and measured a 25 foot band containing gold, which we will follow above the level as long as it produces gold.
As ever, it is not possible to accurately predict future gold production. This is, however, the first area we have explored since the beginning of the strike in January 1992, that has potential for the larger 1,000 to 10,000 ounce pockets for which the Sixteen to One in known.
On the Technology Front
We are currently exploring various gold location technologies by offering the mine as a testing site to the manufacturers and inventors of gold detectors, who bear their own costs for the tests.
Ground Penetration Radar
While our on-site tests of ground penetration radar (GPR) did locate gold in the mine, the data generated by the tests does not readily translate into action plans for mining. We have concluded that commitment to this technology would require more time and money than currently suits our needs.
Radio Imaging Method
We are planning to run in-mine tests of a gold location technology called radio-imaging method (RIM) in November. RIM's claimed ability to locate major gold deposits is based on the conductivity contrast between quartz and gold. We will keep you posted.
You can watch the GPR tests at the Sixteen to One on a six-minute segment of the Discovery Channel's "The Next Step," which will be shown on October 20, 1992 at 9:30 p.m. PST.
A fifteen-minute special on the mine will air on PBS's "California Gold" in January or February of 1993.
Look for a major article and photo spread on the Sixteen to One in the November-December issue of Sierra Heritage.
Status of the Mill
We are currently milling ore from the 2200 level. As we had anticipated (see Newsletter # 22), this ore is producing a higher grade of gold (.3 ounces per ton) than our earlier mill runs. While we once predicted a recovery of about 1,000 ounces of gold from this rock by September 15, 1992, other work in the mine pre-emptied some of our crews from removing ore for the mill to process. As a result, 1,000 still seems like affair prediction for ore from the 2200 level, but the project may extend until the end of the year.
De-watering the 2400 Level
Wastewater discharge from our milling operations has caused a rise in the water level in the 2400 level. It will take three people about two weeks to fix this problem. As clearing the 1500 level has been a more important priority in the last two months, the 2400 level remains under water for the moment.
Michael M. Miller