Legend Mining intersects significant nickel-copper sulphides at Mawson prospect

Legend Mining Limited (ASX: LEG) has announced the intersection of 24.65 metres of nickel-copper sulphides across two separate intervals from the drilling at the Mawson prospect within its Rockford project in Western Australia.

The company announced that the diamond drillhole RKDD021 intersected a total of 24.65m of Ni-Cu sulphides across two intervals; 9.3m of heavy disseminated to net-textured sulphide from 132.2m – 141.5m downhole; and 15.35m of net-textured, heavy disseminated and semi-massive sulphide from 219.1m – 234.45m downhole.

LEG said that it is mobilising DHTEM crew and expert structural geologist to site. The company said that the diamond, RC, and aircore drilling is ongoing at Rockford project.

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.

Legend achieved a watershed milestone in December 2019 at the Mawson prospect at its Fraser Range Rockford Project with the discovery of massive nickel-copper sulphides in diamond drillhole RKDD007.

A structural report from analysis of the core from the discovery hole and the final assays in January 2020 supported the Company’s view that the hole was part of a large mineralised system. 

Subsequent review and modelling of the downhole EM survey data and geological input has identified an off hole conductor which is a compelling drill target for the first diamond drillhole in the March 2020 programme.

Diamond drilling at Mawson

The company had designed diamond drillhole RKDD021 to test a strong 12,000-14,000S off hole conductor identified from a downhole electromagnetic survey (DHTEM) in RC drillhole RKRC013.

LEG reported that the DD hole RKDD021 is currently at 312.4m and has intersected two intervals of Ni-Cu sulphide mineralisation across two intrusive packages separated by a metasedimentary unit.

RKDD021 intersects significant nickel copper sulphides

Legend Mining reported that the diamond drillhole RKDD021 intersected a total of 24.65m of Ni-Cu sulphides across two intervals.

The company noted that importantly, both Ni-Cu sulphide intervals occured within fertile mafic-ultramafic intrusive packages, not metasediments, suggesting the intrusive source of the previously intersected mineralisation at Mawson has potentially been identified.

Upper mineralised interval

LEG said that the upper mineralised interval totalled 9.3m of heavy disseminated to net-textured Ni-Cu sulphides in an olivine websterite/olivine gabbronorite host from 132.2m – 141.5m downhole.

Lower mineralised interval

The company reported that the lower mineralised interval totalled 15.35m of semi-massive, net-textured, and heavy disseminated Ni-Cu sulphides in an olivine gabbronorite host from 219.1m – 234.45m downhole before intersecting a metasedimentary unit, interpreted as a basal contact.

DHTEM to be completed

The company said that DHTEM is planned to be completed in RKDD021, and in the adjacent RKRC021, which was drilled specifically to provide an additional DHTEM platform in this location. This will facilitate additional vectoring of Ni-Cu mineralisation intersected in RKDD021.

Drill core to be logged

Legend said that the drill core from RKDD021 will be structurally logged before being sampled and submitted for analysis.

Next steps

Legend Minerals reported that future programmes at Mawson includes completion of DHTEM surveying in diamond drillhole RKDD021; completion of DHTEM in RC drillholes RKRC015-021 and processing/interpretation of results; structural logging of RKDD021 drill core by Jon Standing from Model Earth; continuation of RC drilling programme testing the eastern geochemical anomaly; full integration of geological, geophysical and geochemical data; and completion of infill aircore drill programme across the greater Mawson area.

The company said that the integration of diamond, RC and aircore drilling results into the Mawson dataset to assist future diamond drillhole planning/design is currently ongoing.

Management comments

Legend Managing Director Mark Wilson said: “The observations from this step out hole are an exciting development in the Mawson story. Geologically we have now intersected significant mineralisation several hundred metres to the east north-east of our previous discovery and our geophysical advice is that we probably have not hit the best part of this conductor.

Our proven systematic methodology of DHTEM and structural logging of this hole on completion will provide the data for the design of the next diamond holes in this immediate vicinity. Meanwhile the diamond, RC and aircore programmes are ongoing at Mawson and regionally within the Rockford Project.”

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.