The Bailieston project is targeting epizonal or epithermal gold mineralisation of the Melbourne Zone, which hosts successful modern gold mines including the world-class Fosterville gold mine owned by Kirkland Lake Gold.
The Bailieston project is at the epicentre of the current gold exploration boom in Victoria, being located close to the highly successful Fosterville mine owned by Kirkland Lake Gold. This point is underlined by the arrival of Newmont Exploration in the district with an application for ground immediately to the north of the Black Cat prospect.
Bailieston is located approximately 150km north of the Victorian state capital Melbourne, with good road access. The project is located geologically within the major orogenic Lachlan Fold Belt (LFB). The LFB is subdivided into zones, based on distinct geological and metallurgical characteristics, with the Bailieston project lying to the east, within the Melbourne Zone.
The project area consists of Siluro-Devonian sediments intruded by Devonian granite stocks. Mineralisation is hosted by vein or stockwork structures, typically within anticlinal trap structures within the sediments.
The Bailieston area has a modest historical production history from alluvial and vein quartz mines. It has a more recent history of exploitation of low-grade, bulk mining stockwork or layered vein structures such as the Bailieston open cut mine which was operated by Perseverance Corporation Ltd in the 1990s.
Other modern nearby open cut gold operations which operated include Hill 158 at Nagambie, Red Hill at Heathcote and the various pits at Fosterville and Costerfield. These latter two continue to operate as higher-grade underground mining operations. The Fosterville mine is located approximately 50km west of the Bailieston project.
Significant intersections from Q1 2019 reverse circulation (RC) drilling by MGA at the Blue Moon prospect within the Bailieston project area included 2 metres at 17.87 g/t gold from 57 metres down hole in BBM007 within a zone of 15 metres at 3.81 g/t gold from 51 metres, and 3 metres at 3.88 g/t gold from 170 metres down hole within a zone of 11 metres at 2.42 g/t gold from 169 metres in hole BBM006. These intersections are apparent width. The results of this programme have confirmed Blue Moon as a new gold discovery within the Bailieston project area. More details regarding the drilling can be found here.
Encompasses the Byron, Maori, Scoulars, Dan Genders, Hard Up and Scanlon’s reefs, and forms the largest area of historical workings (700m by 300m) within the Bailieston project area. MGA’s exploration objective at HR3 is to investigate the possibility of integrating the various reefs at depth to arrive at a meaningful modern-day resource.
There is a gap in the historical workings from the HR3 area for approximately 800m to Cherry Tree to the south and for approximately 400m to the tenement boundary to the north, and there is potential in these zones for undiscovered mineralisation, particularly at depth.
The Black Cat prospect is located immediately south of ground recently applied for by a subsidiary of Newmont Mining, and is among the high priority targets identified by the geophysical interpretation and targeting study completed for MGA in late 2017.
The main Black Cat reef comprises a series of en-echelon quartz lenses within a shear zone, as is found at various other reefs within the Redcastle goldfield. Apart from quartz veined material that was mined historically, there exist siliceous pyritic sandstones and heavily fractured limonitic siltstones that can also be auriferous.
In Q1 2019, MGA completed a reconnaissance rotary air blast (RAB) drilling programme targeting numerous quartz reefs at Black Cat, with a total of 18 shallow holes for 485 metres being drilled. The prospect had never been drilled before. RAB drilling is a low-cost method well suited to the first pass, reconnaissance testing required at the Black Cat gold prospect.
Significant intersections from the drilling included 7 metres at 1.76 g/t gold from 35 metres in BCD11, 3 metres at 4.26 g/t gold from 16 metres in BCD18, and 1 metre at 6.3 g/t gold from 18 metres in BCD03. Intersections in this paragraph are apparent width. More details can be viewed here.
Important geological insights were generated by the drilling programme, which will guide further exploration at Black Cat and other prospects in the Bailieston gold project area.
Blue Moon was identified as a high priority prospect in early 2018 when Dr Rodney Boucher, an experienced Victorian gold geologist, commenced a review of all available data on MGA’s exploration licences (at that time numbering four licences), complemented by geological mapping and geochemical surveys in selected areas. The purpose of this work was to help define targets for a diamond drilling programme extending across a number of MGA’s prospects.
The geochemical surveys utilised a portable XRF to delineate proxy minerals associated with gold. An arsenic anomalous zone up to 40 metres wide and more than 200 metres long was identified at Blue Moon, and previous work showed anomalism over a further 150 metres to the west. Previous rock chip samples included results of 12.1, 10.1 and 7.0 g/t gold, and previous soil surveys identified gold to 5.0 g/t. The diamond drilling at Blue Moon was intended to test the arsenic and antimony anomalies identified by the soil geochemical survey completed by MGA in early 2018.
Positive results from the drilling were announced in July 2018. Diamond drill holes BBM001 and BBM002 were designed to establish the dip of the host sandstones and assess the potential for gold mineralisation. Upon drilling faulted, stockworked sandstone in the first two holes, BBM003 was drilled down dip to test the nature of the cross-cutting faults and veins and to obtain a large number of samples for analysis. An intercept of 39.5 metres at 0.3 g/t gold from 24.2 metres, including 2.7 metres at 1.12 g/t gold from 60 metres, was obtained in BBM003. Intersections given in this paragraph are apparent width.
Given the deep weathering and the potential for gold depletion in the oxidised sulphides, it was considered possible that higher grades would be encountered at depth in the fresh (un-weathered) rock. Obtaining samples from fresh rock was a key objective of the reverse circulation (RC) drilling completed at Blue Moon in February 2019. The twelve RC holes (BBM004-15, for 1,718 metres in total) aimed to intercept the sandstone on 50 metre spacing across three sections and to gain samples from beneath the oxide zone.
The RC drilling programme returned significant intersections of gold mineralisation in nine holes (please see announcement here). Based on the results of this programme, together with other exploration as summarised above, Blue Moon constitutes a new gold discovery within the Bailieston project area. Significant intersections from the Q1 2019 RC drilling included 2 metres at 17.87 g/t gold from 57 metres down hole in BBM007, within a zone of 15 metres at 3.81 g/t gold from 51 metres, and an intersection of 3 metres at 3.88 g/t gold from 170 metres down hole within a zone of 11 metres at 2.42 g/t gold from 169 metres in hole BBM006. Intersections given in this paragraph are apparent width.
Gold mineralisation at Blue Moon is associated with sandstone plus dykes intruding the sandstone and adjacent to it. Sericitic alteration, silicification, sulphide development and gold mineralisation are restricted to the host sandstone with rare sulphides developed in the dykes. Quartz is generally low to absent, even in drill hole BBM007 where quartz was estimated at up to 2% and arsenopyrite at up to 1%.
The RC drilling results indicate that the host sandstone is thicker and the gold grades significantly higher on the westerly section, and further exploration will therefore seek to follow the system to the west, subject to agreeing access with landowners. Further exploration to the west would initially comprise surface geochemical sampling, potentially followed by drill testing.