Increase in Westralia Resource to 610,000 Gold Ounces
Perth, Dec 19, 2013 AEST (ABN Newswire) - Dacian Gold Limited (
ASX:DCN) ("Dacian") is pleased to announce a Mineral Resource increase for the Westralia gold deposit to 3.2Mt at 5.9g/t Au for 610,000oz.
The increase from the previously reported resource estimate of 364,000 ounces was largely due to the inclusion of mineralisation defined from Dacian's recent successful drilling of the high grade Millionaires Shoot. The Millionaires Shoot by itself comprises a high grade resource of 1.3Mt at 7.6g/t Au for 326,000oz.
A summary of the updated Westralia Mineral Resource is shown below.
Westralia Deposit December 2013 Mineral Resource Estimate (2g/t Au Lower Cut-off)
-------------------------------------Classification Tonnes Au g/t Au Oz-------------------------------------Measured 150,000 5.0 24,200Indicated 951,000 5.2 158,000Inferred 2,112,000 6.3 428,000-------------------------------------Total 3,213,000 5.9 610,000-------------------------------------
Significantly, the increase of the Mineral Resource for the Westralia deposit brings the total resource inventory for the Mt Morgans project to 9.2Mt at 4.0g/t for 1.17Moz.
The 610,000oz Mineral Resource at Westralia is defined over a vertical interval of 570m giving an average endowment of over 1,000 ounces per vertical metre.
This major, high grade resource upgrade confirms the Westralia deposit as having the potential for development as an underground mine.
Managing Director Paul Payne commented "The discovery and delineation of the 326,000oz, high grade Millionaires Shoot in less than 12 months demonstrates the potential of the Mt Morgans project for the discovery of further substantial, high grade deposits with clear economic potential. In 2014, we will remain focused on adding further high quality ounces at Mt Morgans as we work towards achieving our goal of building Ore Reserves to underpin a standalone mining operation at the Project."
Westralia Mineral Resource
Gold mineralisation at Westralia occurs within a well-defined, steep east-dipping banded iron formation (BIF) horizon from which approximately 900koz was produced up to 1998. Gold is associated with pyrrhotite and pyrite replacement of magnetite within zones of silica and albite alteration of the BIF. Previous mining at the deposit has demonstrated that the gold is free milling with good recoveries achieved from conventional CIL processing.
Open pit mining at the deposit was carried out to a maximum depth of 120m below surface. Underground mining then proceeded in the northern portion of the deposit to a depth of 240m. Several exploration drives and associated underground drilling was completed in the 1990s to explore the southern portion of the deposit and the geological and assay data from this work has been incorporated into the new Mineral Resource estimate. The extent of historic mining operations and the boundaries of the Mineral Resource are shown in Figure 1.
All mineralisation within the open pit and underground excavations has been excluded from the reported Mineral Resource. In addition, all remnant mineralisation around the main area of workings has been removed from this Mineral Resource estimate even though some areas remain unmined.
The Westralia resource estimate was prepared by consultants RungePincockMinarco Limited (RPM) in accordance with the guidelines of the JORC Code (2012 edition). The deposit has been delineated in the upper levels by face sampling of development drives, underground diamond drilling and surface diamond drilling and minor RC drilling. The deeper portion of the deposit has been delineated by surface diamond drilling. The Millionaires Shoot is largely defined by Dacian diamond drilling from 2013. The Mineral Resource has been reported at a 2g/t lower cut-off to reflect its potential development as an underground mining operation.
The Westralia resource has been estimated using 470 face sample lines, 167 RC holes and 97 diamond holes. Drilling in the deposit extends to a vertical depth of approximately 570m and the mineralisation was modelled to that depth. The estimate is based on good quality surface RC, surface and underground diamond drilling and face sampling data.
Core drilling was predominantly NQ diameter, with sampling based on geological intervals typically 0.2-1.5m in length. Core was cut in half to provide a sample weight of approximately 3kg. All RC drilling was sampled at 1m intervals in the mineralised zones.
Bulk density was determined from 796 samples from Dacian drill core. The density values used for the estimate were 3.12t/m3 for mineralised BIF and 2.82t/m3 for other mineralised rock types. This was consistent with historic density values used at the deposit.
Sample preparation and assay procedures for historic work have not been documented, however the work was carried out by contract laboratories using industry best practice at the time. QAQC procedures for historic data were not documented however Dacian drilling has returned results consistent with the historic drilling.
Dacian samples were submitted to Bureau Veritas laboratories in Kalgoorlie and Perth. Samples were crushed and pulverized then sub-sampled for a 40g fire assay with ICP or AAS analysis.
Since commencement of drilling, Dacian has implemented a consistent QAQC system utilising standards, blanks and duplicate samples. Results have been satisfactory.
The deposit was estimated by RPM using Ordinary Kriging grade interpolation, constrained by resource outlines based on geological interpretation of the BIF horizons. Mineralisation envelopes were prepared using a nominal 0.5g/t Au cut-off grade. The Millionaires Shoot was domained separately with hard boundaries used for estimation.
The block dimensions used in the model were 20m NS by 5m EW by 10m vertical with sub-cells of 2.5m by 0.625m by 1.25m and the model was rotated -30ยบ to match the approximate strike of the mineralisation. Samples were composited to 1m intervals for estimation. A high grade cut of 70g/t Au was determined by statistical analysis and applied to the 1m composite data within certain lodes.
The resource was classified as Measured, Indicated, and Inferred Mineral Resource based on data quality, sample spacing, and lode continuity. The Measured portion of the deposit was assigned to areas of the deposit defined by extensive open cut and underground grade control drilling (10m strike spacing) and face sampling which confirmed the geological and grade continuity of the mineralisation. The Indicated Mineral Resource was defined within areas of close spaced diamond and RC drilling of less than 30m by 30m, and where the continuity and predictability of the lode positions was good. The Inferred Mineral Resource was assigned to areas of the deposit where drill hole spacing was greater than 30m by 30m, where small isolated pods of mineralisation occur outside the main mineralised zones, and to geologically complex zones.
A summary of the Mineral Resource is shown in Table 1.
Table 1: Westralia Deposit December 2013 Mineral Resource Estimate (2g/t Au Cut-off)
------------------------------------Millionaires Shoot------------------------------------Classification Tonnes Au g/t Au OzMeasured 35,000 4.0 4,500Indicated 146,000 5.9 27,600Inferred 1,151,000 8.0 294,200Total 1,331,000 7.6 326,300-------------------------------------Westralia Other Zones-------------------------------------Classification Tonnes Au g/t Au OzMeasured 115,000 5.3 19,700Indicated 805,000 5.0 130,300Inferred 961,000 4.3 133,800Total 1,881,000 4.7 283,700------------------------------------Total Mineral Resource------------------------------------Classification Tonnes Au g/t Au OzMeasured 150,000 5.0 24,200Indicated 951,000 5.2 158,000Inferred 2,112,000 6.3 428,000Total 3,213,000 5.9 610,000------------------------------------
To view tables, figures and charts, please visit:
http://media.abnnewswire.net/media/en/docs/ASX-DCN-662339.pdf
About Dacian Gold Ltd
Dacian Gold Limited (
ASX:DCN) Mt Morgans Project hosts high grade Mineral Resources of 2.1 million ounces at an average grade of 2.6 g/t gold, including Ore Reserves of 136,000 ounces at an average grade of 6.2 g/t gold. In addition, the Company has identified multiple exploration targets and resource extension opportunities. If proven, they will enable growth of the Mt Morgans' existing Mineral Resource and Ore Reserve base.
Dacian's strategy at Mt Morgans is evolving toward mine feasibility and potential mine development. It has identified two large mineralised systems at Westralia and Jupiter where it believes mine development at each site is a possibility, and will be the subject of ongoing drilling and feasibility studies. Dacian considers a high grade Ore Reserve of at least 600,000 ounces of gold is reasonably likely to provide sufficient returns to justify the investment capital required to construct an ore processing facility at the project.
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