asked the Minister for Energy if he will confirm the tonnage and grade of the proven and probable ore reserves which now exist in the whole Navan lead and zinc deposit as per the standard US Bureau of Mines definitions of "proven" and "probable" ore.
Written Answers. - Navan Mines.
32.
The following information has been furnished to me by Tara Mines Limited and Bula Limited.
Proven and Probable Ore Reserves (undiluted) at 31 December 1985
|
Tonnes |
Combined Lead-Zinc Grade |
Cut-off Grade |
|
|
Tara Mines Ltd |
27,562,000 |
11.6% |
5% combined lead and zinc |
|
Bula Ltd. |
13,014,000 |
10.7% |
4% zinc equivalent |
Information in regard to tonnages based on the same cut-off grades for each part of the deposit is not available. It should be noted that a higher cut-off grade gives rise to a lower tonnage figure.
These reserves are in situ reserves all of which may not be mineable.