Legend Mining uncovers multiple massive sulphide intersections at Mawson

Legend Mining Limited (ASX: LEG) has announced a highly encouraging update from the drilling at the Mawson prospect within its Rockford Project, Fraser Range in Western Australia.

The company reported that five intervals of significant nickel-copper sulphide mineralisation totalling 41.5m were intersected, of which three of them comprise massive sulphides of pyrrhotite-chalcopyrite-pentlandite.

The summary of these sulphide intervals are; 148.0-153.8m (5.8m): Heavy disseminated to semi-massive Ni-Cu sulphides; 153.8-164.2m (10.4m): Semi-massive, heavy disseminated & massive Ni-Cu sulphides; 199.4-205.0m (5.6m): Massive Ni-Cu sulphides; 218.2-225.1m (6.9m): Massive Ni-Cu sulphides; and 234.9-247.7m (12.8m) Massive Ni-Cu sulphides.

Rockford Project

The Rockford Project is located in the highly prospective Fraser Range district of Western Australia. The project comprises 14 contiguous granted exploration licences covering a total area of 3,088km2.

Exploration is primarily focussed on Nova-Bollinger style nickel-copper, along with volcanogenic massive sulphide (VMS) style zinc-copper-silver and Tropicana style structurally controlled gold mineralisation.

Six priority prospects within the Rockford Project include magmatic nickel-copper sulphide style targets at Mawson, Octagonal, Magnus and Crean and VMS style zinc-copper-silver targets at Shackleton and Worsley.

Drilling at Mawson

The company had commenced the drilling at its first diamond drillhole this year at the Mawson prospect. Diamond drillhole RKDD008 was designed to test a strong 6,000-8,000S offhole conductor identified by downhole electromagnetic (DHTEM) surveying in RKDD007.

This offhole feature was interpreted to represent the down plunge extension of significant nickel-copper sulphide mineralisation previously identified in RKDD007 (14.9m @ 1.07% Ni, 0.75% Cu, 0.06% Co from 114m).

The company said that the visual and geological observations from the hole RKDD008 demonstrate the presence of materially significant mineralisation at Mawson.

RKDD008 strikes massive sulphide intersections

The company announced that RKDD008 intersected five significant intervals of nickel-copper sulphide mineralisation, three of which comprise massive sulphides of pyrrhotite-chalcopyrite-pentlandite.

The company said that the intervals have a combined downhole thickness of 41.5m. A summary of these sulphide intervals is provided below.

• 148.0-153.8m (5.8m): Heavy disseminated to semi-massive Ni-Cu sulphides

• 153.8-164.2m (10.4m): Semi-massive, heavy disseminated & massive Ni-Cu sulphides

• 199.4-205.0m (5.6m): Massive Ni-Cu sulphides

• 218.2-225.1m (6.9m): Massive Ni-Cu sulphides

• 234.9-247.7m (12.8m) Massive Ni-Cu sulphides

LEG said that RKDD008 intersected a suite of mafic/ultramafic intrusives, mafic granulite, and metasediments.

The company reported that the upper portion of the hole is dominated by olivine mafic/ultramafic intrusives containing disseminated and net-textured sulphides, with the first sulphides occurring at 102.2m. This halo of disseminated sulphide is similar in character to that observed in RKDD007.

A mixed package of mafic intrusive, mafic granulite and metasediment then follows to 247.7m and contains five significant sulphide intervals. This is underlain by a footwall sequence of pelitic metasediment and granulite.

Sampling to commence soon

The company reported that the sampling of the drill core for assay has not been undertaken at this stage. LEG said that this will be completed immediately following detailed structural logging with assay results expected 2-3 weeks later.

LEG said that an extensive programme of DHTEM surveying with multiple loop configurations has commenced to test for extensions to the mineralisation and will assist future drillhole design.

Next steps

Legend Mining reported that future work includes detailed structural logging of RKDD008 by Jon Standing prior to core cutting and sampling of all sulphide intervals; completion of RKDD008 DHTEM survey followed by interpretation of data; and integration of geological and geophysical data from diamond drillholes RKDD007 and RKDD008 into the Mawson 3D geological model.

The company said that it plans to continue diamond drilling of hole RKDD009 under previous aircore drillhole RKAC151, which returned anomalous Ni-Cu-Co geochemistry and also continue infill aircore drill programme. The company said that it is also planning further diamond drillholes.

Management comments

Legend Managing Director Mark Wilson said: “Legend’s 2020 field season has had a spectacular start. The three massive sulphide intercepts clearly stamp this hole as the most significant and exciting discovery in the Fraser Range post Nova. It has been a true team effort, hats off to all concerned!

A downhole EM survey and structural analysis of the core are now being undertaken. The results of these next steps will enable us to design the drill programme to further delineate this mineralisation.

Samples for assay will be sent to the laboratory following the completion of the structural analysis and results are expected 2-3 weeks thereafter.

Meanwhile the diamond rig has relocated to drill the next hole under the discovery aircore hole RKAC151. We look forward to updating the market as new results come to hand.”

Written By Jonathan Norris
Jonathan is a founder of Mining.com.au and has been covering the resources industry since 2018. With over 17 years experience in print, broadcast and online media, Jonathan has seen first hand the transformative effect of online niche media.