Helix Resources Ltd (ASX:HLX) continues to demonstrate the success of its Induced Polarisation (IP) geophysical survey techniques in identifying potential copper targets along Rochford Trend at the Canbelego JV Project in the Cobar Basin of central NSW.
Results from new geophysics have delineated multiple features considered prospective for copper mineralisation at the Bijoux copper prospect with a prospective 2-kilometre-long zone identified.
Conductive units
A 5-square-kilometre gradient array induced polarisation (GAIP) survey has been completed over the Bijoux copper prospect and this has highlighted GAIP conductive units coincident with surface copper geochemical anomalism and recent significant copper drill assay results.
The objective of the GAIP survey is to identify conductivity anomalies, which may be directly associated with copper sulphide, or with conductive rocks that may host copper sulphide.
Bijoux GAIP survey showing resistivity results, copper anomalies, conductive units (open to the north and south) and the prospective zone that contains coincident conductive units and copper anomalism.
“High confidence”
Helix’s executive technical director Kylie Prendergast said: “In the Rochford Trend we are exploring for Cobar-style, high-grade, copper deposits. The direct analogue is the large-scale CSA copper deposit located 50 kilometres away which contains a series of rich, stacked copper lodes, some of which are hidden but can be identified with IP geophysics.
"In February 2024, we reported we were successful in using IP geophysics to identify two new 'look-alike' anomalies to the west of the Canbelego Main Lode copper resource.
"At Bijoux, we have high confidence that the geophysical surveys are an effective tool to focus in on the mineralised structures that contain the copper. Now we will move to pole dipole induced polarization (PDIP) geophysics to identify chargeability zones that could represent new sulphide copper lodes to drill test.”
Use of geophysics
Helix is using the geophysics to rapidly delineate potential copper targets that correlate with known copper anomalism along the regionally significant Rochford Trend, including at Bijoux.
The effectiveness of geophysics to constrain prospective copper zones at Bijoux follows the successful application of geophysics 9 kilometres to the north at the Canbelego and Caballero deposits.
Previous drill testing at Bijoux intersected high-grade copper oxide and sulphides only tested minor, 200-metre portion of the 2-kilometre coincident geophysics-geochemical anomaly, with the majority of the anomaly remaining undrilled.
This drilling intersected oxide and sulphide copper mineralisation in an area that lies directly over the northern end of a linear 2.4-kilometre-long conductive unit, which is open to the south. Results from the drilling include:
- 36 metres at 0.99% copper from 41 metres including 6 metres at 1.99% from 62 metres in oxide;
- 10 metres at 1.48% from 182 metres including 2 metres at 5.76% from 184 metres in sulphide; and
- 11 metres at 0.94% from 140 metres including 4 metres at 1.90% from 144 metres in sulphide.
Follow-up plans
The GAIP survey delineated multiple conductive units which can be traced for a strike length of more than 4 kilometres and are open to the north and south.
Priority areas have been selected for follow-up geophysics to refine drill targets for a proposed drill campaign expected to begin in mid-May.
Rochford Trend, Canbelego to Bijoux area showing copper geochemistry, main structures and IP survey areas.
Follow-up pole-dipole IP (PDIP) lines are in progress in the Canbelego-Caballero corridor and are expected to be completed in late April with the follow-up PDIP survey at Bijoux to commence after that.
“Progressing at rapid pace”
"Helix is actively testing three separate compelling copper targets at Canbelego, Cabellero and now Bijoux with IP geophysics to detect new potential lodes of copper sulphide mineralisation,” Prendergast said.
“The momentum and results to date underpin Helix’s efforts to expand its copper inventory beyond the known copper resource at the Canbelego Main Lode.
"The programs are progressing at a rapid pace and we expect to have delineated drill targets by late April/early May for the proposed May drill program.
“Helix has a large pipeline of quality copper and gold targets across our Western and Eastern tenement groups that we are systematically advancing.”