Legend Mining Limited (ASX:LEG) has signed a contract to carry out a new 3D seismic survey over the Octagonal Intrusive Complex at the Rockford Project, Fraser Range, Western Australia.
The survey covers 24.5 sq. km and has been designed by Barry Bourne of Terra Resources who are retained as consultant for the survey. The data collection phase of the survey is scheduled to commence mid October 2022, with the final processed results by the end of May 2023.
In addition, a fifth diamond drillhole has been completed at Mawson extending the mineralised chonolith further and remaining open to the northwest.
“The results thus far of the five diamond holes drilled at Mawson this year have confirmed the effectiveness of seismic as an exploration tool at the Rockford Project. These results have encouraged Legend to commit to a new +$1M 3D seismic survey at the Octagonal prospect.
“The Octagonal prospect is the fourth known occurrence of massive nickel-copper sulphide mineralisation in the Fraser Zone, the other three being Nova-Bollinger, Silver Knight (both IGO) and Legend’s discovery at Mawson.
“As such, Legend is positioned with two advanced prospects for the discovery of nickel-copper sulphides and a treasury of circa $13M – a truly enviable position for any junior explorer.”
Octagonal
HiSeis has been engaged by Legend to conduct a 3D seismic survey at the highly prospective Octagonal prospect within the Rockford Project, Fraser Range, WA.
The aim of the survey is to define the architecture of the Octagonal Intrusive Complex in relation to the stratigraphic package, to a depth of investigation of a minimum 1500m below surface.
The decision to conduct this +$1M survey is based on the results Legend is generating from the drilling of seismic targets at the Mawson prospect.
HiSeis are scheduled to mobilise to site in mid October 2022 to commence the data acquisition phase of the 3D seismic survey which is planned to be completed by the end of November 2022. Processing of the data and delivery of the final 3D model is scheduled for May 2023.
On receipt of the results of this 3D seismic survey, Legend will conduct an intensive process of interrogation, including incorporation of existing geophysical, geological, geochemical, and structural datasets with the aim to define and rank new diamond drilling targets for the 2023 field season at Octagonal.
Octagonal Prospect Background
The Octagonal Intrusive Complex was originally targeted by the Creasy Group due to its distinctive “eye” aeromagnetic feature, which has remarkably similar shape and size characteristics with the Nova “eye”.
Soil sampling and aircore drilling across Octagonal returned anomalous Ni-Cu values and identified highly favourable Ni-Cu host rocks including olivine gabbronorite, troctolite, peridotite, gabbronorite and norite. RC and diamond drilling was then undertaken, mainly on the south-eastern and southern margins of the intrusive complex targeting EM conductors and IP features.
Mawson
Diamond drillhole RKDD085 was designed to intersect a seismic signature replication of that identified by diamond drilling ~150m south. The geological, structural, and seismic interpretation was that the mineralised chonolith continues to the north-west of existing diamond drilling coverage.
The drillhole intersected and extended the mineralised chonolith as predicted, confirming the chonolith extends and remains open to the north-west. The upper level of the main target zone encountered a prospective mafic intrusive with lesser ultramafic.
The lower target zone intersected more ultramafic intrusive with variable zones of disseminated to blebby magmatic sulphide. The drillhole finished in a metasedimentary package as predicted by the seismic interpretation. Further data analysis is underway, including structural vectoring and additional aircore drilling, which will aid in refinement of this new target zone.
DHTEM and assay results are pending. Petrophysical property measurements are underway with hand-held and downhole instrumentation, with results pending. Diamond drilling for the current programme has been completed.
Current outstanding data includes physical property data, DHTEM modelling, detailed structural analysis, and critical multi-element assay data.
These datasets are key components to reprocessing, modelling, and interpretation of the 3D seismic cube at Mawson. Once received, reprocessing of the 3D seismic data will be undertaken to refine existing models, refine existing targets, and define new targets across the Mawson intrusion.