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ABN 98 139 357 967
Board of DirectorsAshok Parekh
Non-Executive Chairman
Jeff Williams
Managing Director
Peter Rozenauers
Non-Executive Director
ASX Announcement 10 May 2016
New High Grade Nimbus Silver Core Averaging 968 g/t Ag- Revision of the Nimbus resource modelling and estimates have identified a high grade resource within the existing Nimbus resource boundaries.
- Underground Lodes 3, 4, 5 & 7 contain a high-grade silver-zinc core of 132,075 tonnes @ 968 g/t silver (Ag) or 31 ounces/tonne (oz/t) & 19% zinc (Zn) for 4.1 million ounces of silver and 25,000 tonnes of zinc.
- The underground lodes vary in width from 1 to 4 metres and intercept the wall of the existing Discovery open pit and extend to a depth of 200 metres below the pit.
- The high-grade core lies in an overall envelope of a silver-zinc resource for the Nimbus underground project of 255,898 tonnes @ 773 g/t Ag and 13% Zn (using a bottom cut-off grade of 500 g/t Ag). The resource contains an estimated 6.4 million ounces of silver and 33,000 tonnes of zinc.
- Trial metallurgical test work achieved silver recoveries of up to 97.18% from zinc concentrate.
Macphersons Resources (ASX:MRP) is pleased to advise that a new high grade silver zinc resource has been estimated from within the global Nimbus resource of 12.1 million tonnes at 52 g/t silver, 0.9% zinc. 0.2 g/t gold containing 20.2 million oz of silver, 78,000 oz of gold and 104,000 tonnes of zinc.
The high grade underground silver zinc resource for the Nimbus project of 255,898 tonnes @ 773 g/t Ag and 13% Zn has been estimated using a higher modelling cut-off grade of 500 g/t Ag and a top cut grade of 2800 g/t Ag was applied.
The high grade resource inventory includes lodes 3, 4, 5 & 7 from the high grade silver zinc resource which total 132,075 tonnes @ 968 g/t Ag & 19.36 % Zn (bottom cut-off grade 500 g/t Ag & top cut grade 2800 g/t Ag). .
The recently increased geological understanding of Nimbus deposit provides MRP with a high level of confidence in the new high grade silver zinc resource however further work is required to bring the resource up to a level required for future Ore Reserve estimations to be completed.
This resource model enables MRP an opportunity to evaluate options of a high grade underground mining scenario for the Nimbus deposit.
Table 1: Nimbus high grade silver zinc resource
Resource Lode Volume (m3) Tonnes Ag (ppm) Zn (%) Ag (Ozs) Zn (t)
1 | 15,430 | 45,235 | 670.27 | 8.96 | 974,799 | 4,055 | |
2 | 9,210 | 27,077 | 529.41 | 8.16 | 460,875 | 2,209 | |
Indicated | 4 | 27,010 | 79,409 | 921.36 | 19.17 | 2,352,284 | 15,220 |
8 | 7,080 | 18,866 | 645.62 | 1.39 | 391,604 | 262 | |
Sub Total Indicated | 58,730 | 170,587 | 762.07 | 12.75 | 4,179,569 | 21,746 | |
3 | 2,840 | 8,350 | 893.5 | 23.35 | 239,868 | 1,949 | |
5 | 12,770 | 35,761 | 992.84 | 18.58 | 1,141,510 | 6,645 | |
Inferred | 6 | 10,790 | 28,559 | 332.66 | 0.93 | 305,446 | 267 |
7 | 2,910 | 8,555 | 1377.17 | 20.46 | 378,790 | 1,751 | |
10 | 1,390 | 4,087 | 921.88 | 12.18 | 121,135 | 498 | |
Sub Total Inferred | 30,700 | 85,311 | 797.26 | 13.02 | 2,186,733 | 11,109 |
Grand Total | 89,430 | 255,898 | 773.80 | 12.84 | 6,366,302 | 32,855 |
Figure 1: Plan view of the Nimbus high grade silver zinc lodes
Table 2: Nimbus high grade silver lodes 3,4,5,7
Resource Category | Lode | Volume (m3) | Tonnes | Ag (ppm) | Zn (%) | Ag (Ozs) | Ag (t) |
Indicated | 4 | 27,010 | 79,409 | 921.36 | 19.17 | 2,352,284 | 15,220 |
Sub Total Indicated | 27,010 | 79,409 | 921.36 | 19.17 | 2,352,284 | 15,220 | |
Inferred | 3 | 2,840 | 8,350 | 893.50 | 23.35 | 239,868 | 1,949 |
5 | 12,770 | 35,761 | 992.84 | 18.58 | 1,141,510 | 6,645 | |
7 | 2,910 | 8,555 | 1377.17 | 20.46 | 378,790 | 1,751 | |
Sub Total Inferred | 18,520 | 52,666 | 1039.52 | 19.64 | 1,760,167 | 10,345 | |
Grand Total | 45,530 | 132,075 | 968.48 | 19.36 | 4,112,452 | 25,565 |
Figure 2: Long section of the Nimbus high grade silver zinc lodes
Nimbus High Grade Resource Geological ReviewA geological review of the Nimbus VHMS Ag-Zn deposit has enabled MRP to confidently high grade the existing resource. The geological understanding of the nature of mineralisation at Nimbus has increased significantly recently due to a combination of previous work undertaken by MRP geologists, a joint CSIRO/GSWA study and a recently completed Bachelor of Science Honours thesis titled "Host Rock Succession to the Archaean Nimbus Deposit".
Work completed by MRP geologists included the relogging of historic diamond core (approx. 18,000 metres) and reverse circulation (RC) chips which enabled consistent rock and alteration naming nomenclature to be applied across the deposit for the first time. This work culminated in the construction of 3D geological models of Nimbus deposit including a lithology model, mineralisation model and structural model.
A joint CSIRO/GSWA research project undertaken by Dr Steven Hollis involved collecting Nimbus drill samples for petrographic and mineralogical determination, whole rock geochemical analysis, pXRF analysis, hyperspectral analysis and U-Pb zircon SHRIMP age dating. The age dating undertaken on the Nimbus dacite host unit resulted in age dates of 2703 ± 5 Ma and 2702 ± 4 Ma.
MacPherson Resources Limited published this content on 10 May 2016 and is solely responsible for the information contained herein.
Distributed by Public, unedited and unaltered, on 10 May 2016 00:34:05 UTC.
Original documenthttp://www.mrpresources.com.au/downloads/announcements/mrp_2016051001.pdf
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