Legend Mining Ltd (ASX:LEG) has wrapped up the data processing phase of a 3D seismic survey over a more-than-24-square-kilometre area at the Octagonal prospect, part of the Rockford Project, Fraser Range, Western Australia.
HiSeis was engaged by Legend to conduct a 3D seismic survey at the highly prospective Octagonal with the aim of defining the architecture of the Octagonal Intrusive Complex (OIC) in relation to the stratigraphic package, to a minimum depth of investigation of 1,500 metres below surface.
Data processing complete
The company has invested more than $1 million in the survey, buoyed by strong drilling results from seismic targets explored at the Mawson deposit in 2022.
Field teams carried out data collection in November 2022 and processing is now done – the task is now to incorporate existing data sets and conduct further interpretation.
Legend is optimistic that the seismic work, combined with existing geophysics, depicts compelling nickel-copper sulphide targets outside previous drilling, and that it has identified the potential feeder structure of the Octagonal intrusion.
“The Legend technical team is extremely pleased to see the detail of the Octagonal seismic cube which shows a strong correlation with geophysical models and structural interpretations from previous drill data,” Legend managing director Mark Wilson said.
“In addition, the cube gives new information below and outside of existing drilling, all of which will assist in the ranking of holes for the diamond drill program at Octagonal scheduled for commencement in May 2023.”
The results highlight what Legend calls the excellent correlation between the seismic dataset and the existing structural interpretation.
Exploration model supported
The newly acquired 3D seismic data supports the exploration model that the OIC continues at depth below drilling completed to date. 3D seismic reflectors clearly map the eastern and western sidewall contacts of the OIC, confirmed by diamond drilling, and importantly the basal contact.
The limited RC and diamond drilling completed to date has intersected multiple intervals of massive, semi-massive, net textured, stringer and disseminated pyrrhotite-pentlandite-chalcopyrite sulphides associated with the mafic/ultramafic intrusives of the OIC.
This mineralisation demonstrates all the characteristics of a fertile magmatic nickel-copper sulphide system, akin to deposits at Nova-Bollinger, Silver Knight, and Mawson in the Albany-Fraser Belt.
Octagonal sits within the same structural corridor that hosts the Nova-Bollinger and Silver Knight intrusions and nickel-copper-cobalt deposits.
What’s next?
Legend and HiSeis will continue to conduct the intensive process of interrogation, including incorporation of existing geophysical, geological, geochemical, and structural datasets.
Modelling to date has already been productive, identifying multiple new drill targets.
The company is organising statutory approvals and the geological team is ranking these new diamond drilling targets for a May start to the 2023 field season at Octagonal.
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