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Aug 2017 - MacPhersons Res

MacPhersons (MRP) Update based on a Pre - Diggers 2017 Visit to Boorara

  • ERA visited MacPhersons Resources’ (MRP’s) Boorara Gold Project on 6 August ahead of Diggers' 2017 to review the progress made since our last report on 7 October 2014. Since that report at 12.5c the share price fell to ~ 5c to 10c before recovering earlier this year to ~28c on the progress at Boorara, and has since drifted back to ~16.5c. The number of shares in issue has only increased by 7m since 2014 to its current level of 317.17m (plus 5m options in-the-money at 15c by 9 Dec 2019) for a ~$53m mkt cap. MacPhersons is currently rated by ERA as a SPEC BUY with a target of >A$0.25.
  • In the past year, 3 significant revelations have occurred in understanding the controls behind the gold mineralisation at Boorara (located only ~10km east of Kalgoorlie’s Super Pit, as shown on page 8 of ERA’s October 2014 report available on www.eagleres.com.au), namely :
  • Excavating a trial pit in the Southern ore zone (SOZ – Boorara consists of 3 zones, North, Central and South) which exposed the geology and vein orientations and confirmed Roland Mountford’s 1985 theory that the grade depended on the drillhole direction at Boorara, producing a ~1.6g/t resource one way, or ~3.2g/t (ie up to double the grade) if drilled from a specified different direction.
  • Drillhole exploration along strike (perpendicular to the veins) showed the continuity and stacked lode package of the mineralisation as shown simplistically in the Figure 1a schematic (and in more detail in Figure 5a). This is similar to what Gold Road (GOR) has drilled at Gruyere, but alas the market mis-labelled MRP as having drilled “down-dip director’s holes” when in E/W cross-section.
  • Commissioning a structural re-interpretation of Boorara by consultant geo Gerard Tripp, who included Boorara in his July 2017 presentation focusing on the Gidji Lake Formation (or Upper Black Flag sequence as a Key Stratigraphic Marker for Kalgoorlie’s World Class Gold Deposits). The presentation included Boorara alongside the comparative geological columns of Kambalda (>12Moz) and Ora Banda (>2Moz). Gerard also referred to John Clout’s revolutionary (for its time) 1989 suggestion that Kalgoorlie’s Golden Mile had a high level overprint as shown in Figure 1b.

Mt Charlotte Similarities

  • This has resulted in the inference that Boorara has a number of similarities with the stockwork gold mineralization of Mt Charlotte (the ~6Moz to 7Moz) system at the Northern end of the Kalgoorlie Super Pit, as it appears to have a number of similar characteristics:
  • To start off you require a differentiated dolerite host rock with mappable (or individually separatable) units – the Golden Mile Dolerite (GMD) has 10 mappable units, Boorara (BD) has ~7.
  • But the key is GMD Unit 8 as shown in Figure 2b as it hosts the main Mt Charlotte orebodies. GMD Unit 8 is a quartz-rich (with visible quartz) granophyric dolerite, as is BD Unit 5 (see Fig 8a). So what else is similar (per MRP’s head geo – Andrew Pumphrey):
  • Gold mineralization is contained in quartz-carbonate sulphide veins within the qtz dolerite unit,
  • The stereonets (note where the cluster is) have similar vein orientations as shown in Figure 3a,
  • There is common mineralization and alteration such as iron carbonate alteration, pyrite mineralization and the presence of scheelite as shown in Figure 3b [now that scheelite has to be a classic filter. There may be other examples in Australia, but ERA has only seen one other example and that was in Finland as per our DRA (Dragon) report and Paydirt article in 2004. Scheelite is a classic identifying unit under ultra violet light – being fluorescent purple].
  • They both have an oxidized chemical composition due to iron enrichment (present as ilmenite, magnetite or titano-magnetite) that provides a favourable wall-rock reaction to reduced gold fluids.
  • They both apply drillholes targeted in the same geometric orientation at veinlet/vein array stockworks within the favourable quartz-rich dolerite unit (GMD 8 or BD 5).
  • Written by: Keith Goode
  • Monday, 28 August 2017