Legend Mining intersects more massive Ni-Cu sulphides at Mawson

by Leena Thomas
Image: Legend Mining Limited

Legend Mining Limited (ASX: LEG) announced that further massive nickel-copper sulphides were intersected from diamond drillholes RKDD024-027 and RC drillholes RKRC022–034 at the Mawson Prospect within its Rockford Project in Western Australia.

The company said that the hole RKDD027 intersected 26.25m of Nickel-Copper sulphide including 15.45m massive sulphide across three zones and 10.80m semi-massive and matrix sulphide across three zones.  LEG also reported multiple Nickel-Copper sulphide intercepts in the holes RKDD024 and RKDD025.

Legend said that it is also planning a 3D model of its Mawson discovery that will visually depict the scale potential of the nickel-copper discovery.

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.

Rockford JV tenements include E28/2188, 2189, 2192 (70% Legend, 30% Rockford Minerals Pty Ltd); and E28/1716, 1717, 1718, 1727 (70% Legend, 30% Ponton Minerals Pty Ltd).

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.

Diamond drilling at Mawson

The company had commenced an infill diamond drill program designed to extend/close off known Ni-Cu mineralisation at the Mawson massive Ni-Cu sulphide discovery.

The drill hole RKDD027 targeted the extension of known mineralisation in RKDD017; RKDD025 was designed to target a very strong 20,000-25,000S DHTEM plate identified above RKDD023; RKDD026 was a structural hole designed to target the northern vector of the sulphide extension veins logged in the Mawson discovery zone; and RKDD024 was designed to test the southern extension of the Mawson Intrusion, including a discrete gravity feature modelled from the processing of the detailed gravity completed across Mawson.

RKDD027 intersects massive nickel-copper sulphide

LEG announced that the drill hole RKDD027 intersected 26.25m of Ni-Cu sulphide including three zones of massive sulphide totalling 15.45m (162.0-174.9m, 175.6-176.45m, and 231.8-233.5m downhole).

The company said that three zones of semimassive and matrix sulphide totalling 10.8m (174.9-175.6m, 188.85-195.2m, and 215.8-219.55m downhole) were also intersected.  LEG also reported the intersection of a disseminated zone from 153.7-162.0m downhole.

RKDD024, RKDD025, and RKDD026

Legend reported that the hole RKDD024 intersected an upper gabbronorite unit with blebby and disseminated Ni-Cu sulphide from 106.4-124.3m, followed by a dominantly norite zone with minor troctolite to 236.1m, before intersecting a mixed norite and meta-BIF package to 275.55m.

LEG said that from drill hole RKDD025, narrow zones of massive sulphide were intersected at 217.02m-217.28 and 223.01m-223.31m, a brecciated sulphide zone from 218.6m-219.14m, and a disseminated sulphide zone from 160.0m- 217.02m.

Meanwhile, DD hole RKDD026 intersected the interpreted western margin of the Mawson Intrusive Complex.

The company said that the structural logging of RKDD023, RKDD025, and RKDD026 has allowed for further development of the Mawson geological model, which will result in more focused drill targeting.

Analysis of sample

Legend said that a massive Ni-Cu sulphide sample from 230.5m downhole of RKDD023 was analysed by the Bruker M4 TORNADO by Portable Spectral Services. The company said that the resulting image clearly identified the pentlandite (Ni) and chalcopyrite (Cu) sulphides within the sample, as well as the textural relationships between the sulphide species, in line with the structural interpretations.

DHTEM update

Legend said that the drill hole RKDD027 confirms that the massive sulphide continues to the west on this section. LEG said that the DHTEM is now scheduled for RKDD027.

The company said that DHTEM is currently underway for diamond holes RKDD024 – 027 with results awaited from hole RKDD025. LEG said that crews will remain on site at Mawson to complete the DHTEM of the completed diamond and RC drillholes. RKDD023-026 have been sampled and submitted for assay.

RC drilling at Mawson

Legend reported that a further 7 RC holes (RKRC028 – RKRC034) were completed at Mawson and assays were received for 1 hole, RKRC022.

LEG said that the RC hole RKRC022 intersected a mineralised gabbronorite with disseminated to net-textured sulphide above a meta-BIF unit.

RC holes to be utilised as DHTEM platforms

The company said that RC drillholes RKRC028 through RKRC031 intersected a metasedimentary assemblage of meta-BIF and metapelites-psammites and mafic granulites. The company said that these holes will now be utilised as DHTEM platforms for off hole targeting. The company said that RKRC032 – RKRC034 are currently being logged.

LEG said that the RC drilling continues to confirm the Mawson Intrusion extends north and east of the known Mawson Ni-Cu sulphide mineralisation, confirming the prospectivity for mineralised intrusives below the eastern aircore geochemical anomaly. Legend said that the geological information is evolving the Mawson geological model and focusing diamond drill targeting.

3D model of Mawson

The company announced that it is currently planning a 3D model of its Mawson discovery that will visually depict the scale potential of the nickel-copper discovery in Western Australia’s Fraser Range. LEG said that this model will aggregate data interpretations from the detailed gravity, magnetics, geochemistry, and structural geology.

Updates and next steps

Legend Mining announced the latest updates and future programs at Mawson. This includes ongoing diamond and RC drilling ; ongoing DHTEM surveying in diamond and RC drillholes; structural logging of completed diamond holes by Jon Standing of Model Earth; reporting assays from samples as received; and integration of diamond, RC and aircore drilling results into the Mawson dataset to assist 3D modelling and future diamond drillhole planning/design.

The company said that it would submit selected drill core from RKDD024, 025, 026, 027 for full analysis. LEG said that further work would include assessment of geochemical results; full integration of geological, geophysical, and geochemical data; planning of further diamond drillholes; continuation of  RC drilling programme at Mawson testing geochemical and geophysical targets; and the ongoing assessment of RC and aircore drilling and geochemical results to assist further RC and diamond drillhole design.

Management comments

Legend Managing Director Mark Wilson said: “The content of the technical discussion within this announcement confirms that work has continued apace at Mawson since our last Mawson announcement on 8 September.

The material widths of the intercepts in hole 27 speak to our confidence of the size potential of the Mawson system, whilst the information from the other reported holes is adding to the bigger picture.

We are planning to release a 3D model of Mawson shortly which will visually depict the scale potential of Mawson in 3D for the first time. This model will aggregate data interpretations from the detailed gravity, magnetics, geochemistry and structural geology.”