The Jamieson project is located on unrestricted crown land within a geological province known as the Mt Useful Slate Belt. The region was founded on gold mining in the 1850s and a number of gold mines have operated or are currently in production in the region.
The project covers a “window” of Cambrian-aged volcanic rocks similar to the Mt Read Volcanics in western Tasmania, a world-class VHMS district. Typically, VHMS deposits occur in clusters and often define significant mining camps. Gold-rich VHMS deposits are particularly attractive targets given their high-grade and polymetallic nature. VHMS deposits are also attractive as exploration targets because they typically respond well to geophysical techniques, and in areas of little or no transported cover such as Jamieson, surface geochemistry and mapping are proven to be effective exploration methods.
Jamieson Project location plan
The most advanced prospect at Jamieson is the Hill 800 gold-copper prospect, a volcanic-hosted massive sulphide (VHMS) gold-copper system with many similarities in host rock, age and mineralisation style to the 1.5Moz Henty gold deposit in western Tasmania. There are also several other high-priority prospects at Jamieson including Hill 700, Mt Sunday Road and Rhyolite Creek, all of which have been identified from a combination of mapping, surface geochemistry and drilling.
Hill 800 was discovered by New Holland Mining NL in 1994, with drilling beneath outcropping gold-rich gossans identifying high-grade gold mineralisation. Carawine’s maiden diamond drilling program of 14 holes for a total 2,376m was completed in June 2018, with outstanding assay results exceeding the Company’s expectations of both the width and grade of gold mineralisation. The program resulted in a significant, new interpretation of the geometry and orientation of the mineralised system with multiple mineralised zones identified. A second phase of diamond drilling commenced at Hill 800 late in November 2018 and continued into 2019.
Hill 800 longitudinal projection looking east, with selected intervals
800 and 740 Zones
The 800 and 740 zones are outcropping, coherent bodies of gold mineralisation characterised by intense silica-sericite-pyrite alteration. These zones have a north-northeast strike with a low dip to the south-southwest and are stacked against the steep, northeast trending Prelude Fault. The low-angle southwest dipping NSX Fault separates the two zones. Preliminary interpretation suggests that these zones may have formed from the preferential replacement of more permeable, volcaniclastic and brecciated layers of the host andesite sequence, resulting in the observed mineralised geometries.
Significant intervals from the 800 Zone include:
Significant intervals from the 740 Zone include:
(Downhole widths, for a full listing of intervals and further details see ASX announcements dated 7 June, 10 July, 6 August and 20 August 2018.)
Approximate dimensions of the 800 Zone from drilling to date are 240m long x 80m wide x 50m high, with mineralisation closed by drilling and outcrop. Approximate dimensions of the 740 Zone are 270m long x 75m wide x 50m high, with mineralisation remaining open along strike to the northeast.
Further repetitions of the 800 and 740 zones are now likely, either as stacked lenses or as faulted offsets by additional structures stepping downwards to the north. An example of this is the newly discovered 650 Zone, as described below.
The 650 Zone is identical in host rock and alteration style to the 800 and 740 Zones and was first discovered in drill hole H8DD015. Assay results reported in this announcement show that this zone has been extended to the north and remains open, with gold grades increasing (see ASX announcement dated 5 February 2019 for details). Significant intervals from the 650 Zone include:
(Downhole widths, for a full listing of intervals and further details see ASX announcements dated 5 February and 1 April 2019.)
Hill 800 mineralisation styles
The Stringer Zone sits below and to the west of the 800 and 740 Zones, and to the east of the 650 Zone, sub-parallel with the Prelude Fault. This zone is characterised by gold and copper mineralisation hosted by a network of high-grade centimetre-scale pyrite and chalcopyrite “stringer” veins within altered andesite lava and brecciated lava. The zone strikes north to northeast, with a steep dip to the west, sub-parallel with the Prelude Fault. Coarse free gold is observed within quartz-chlorite-chalcopyrite-pyrite veins and stringers and within the selvedges to these veins.
Significant intervals from the Stringer Zone include:
(Downhole widths, for a full listing of intervals and further details see ASX announcements dated 7 June, 10 July, 6 August, 20 August 2018; 5 February, 1 April 2019)
The following lists all 1m samples above 10g/t Au in the Stringer Zone within the intersections reported above, characterising the Stringer Zone by its very high gold grade, occasional coarse visible gold and significant levels of copper:
The Stringer Zone is defined to date by four drill holes, having been intersected over about 150m along strike, about 80m down dip, with a true width varying from 3m to about 30m. It remains open with potential for extensions, especially up-dip to surface as indicated by recent DHEM modelling (see ASX announcement dated 5 February 2019 for details).
650mRL level plan showing Stringer and 650 Zones
Petrographic work indicates gold within the 800 and 740 zones occurs within fractures and on the boundaries of pyrite grains, and in the Stringer Zone as free gold. The Company plans to conduct a scoping-level metallurgical test program in H2 2019 using core samples from the current drilling program.
Rhyolite Creek is located 5km to the south of Hill 800, discovered by previous explorers after targeting a linear magnetic anomaly in an area of surface gold-silver-base metal anomalism in surface geochemical samples. The discovery diamond core hole RCD001 intersected a zone of strong albite-chlorite-silica alteration and sulphide mineralisation, returning an interval of:
(Downhole widths, see the Company’s IPO Prospectus released on 12 December 2017 for details)
Zinc mineralisation was identified as being related to low-iron sphalerite and the footwall to this high-grade zone was reported as being strongly altered intermediate volcanics with significantly elevated zinc values over 52m downhole. Carawine believes the high-grade zinc-gold-silver horizon intersected in RCD001 is potentially associated with a VHMS seafloor or sub-seafloor deposit, occurring at the contact of intermediate and felsic volcanic sequences, with wide zones of footwall alteration and anomalism. Additional holes drilled by previous explorers have intersected this position over a strike length of about 400m, leaving it open along strike to the south.
Rhyolite Creek cross-section through RCD001 and RCD002
Sitting above, and either side of the zinc target is a large, anomalous gold-copper mineral system. This is defined by a surface gold soil anomaly above 0.1g/t gold over a 500m x 500m area, with sparse historic drilling returning highly encouraging assay results. Two areas have been initially been identified as requiring follow-work: the Zig Zag Track, 500m southwest of RCD001, and; the Jamieson River South area about 1km southeast of RCD001.
Rhyolite Creek prospect area with historic surface gold and copper anomalism and selected drill intervals
At the Zig Zag Track area, brecciated rhyolite and fragmented epiclastic units with massive sulphides adjacent to a “silica knob” outcrop in two holes yielded the following results (re-calculated from historic data):
At the Jamieson River South area Hole RCK002 intersected near surface gold mineralisation:
(downhole widths, for details refer to the Company’s IPO Prospectus released on 12 December 2017)
Both areas have had only limited follow-up drilling and as such are targets for future drilling.
The Hill 700 prospect, about 600m immediately south of Hill 800, is defined by a coherent 300m long surface gold anomaly above 25ppb Au, with individual samples above 100ppb Au (0.1g/t Au). Of a similar tenor is the Mt Sunday Road prospect where a surface gold anomaly over 500m above 50ppb Au has been defined from historic work (for details see the Company’s IPO Prospectus released on 12 December 2017).
These prospects demonstrate the potential for significant mineralisation beyond the excellent results from Hill 800 and support the Company’s belief that the Jamieson Project can deliver multiple mineral discoveries with further exploration. Evaluation of these prospects along with exploration program design and planning is in progress.
Jamieson Project regional prospects and surface geochemical coverage