Litchfield Minerals' geophysics highlight large-scale NT mineralised system
- Doug Bright
- Nov 4
- 4 min read
Litchfield Minerals’ (ASX: LMS) has revealed the latest geophysical results from its priority VT1 VTEM drill target at its Oonagalabi project in Australia’s NT indicate it sits within a large-scale and fertile mineralised system that could potentially host a company-making discovery.
The conclusion arises from the company’s down-hole electromagnetic (DHEM) survey of its first VT1 drillhole, following completion of the first hole into the target which was completed around October 23.
The results of Litchfield’s down-hole electromagnetic (DHEM) survey of its first VT1 drillhole – completed around October 23 - raised more than a few eyebrows among the company’s geologists.
The hole intercepted about 46m of lightly disseminated copper–iron dominant pyrrhotite, pyrite and chalcopyrite sulphide mineralisation, visible in logging, between 69m and 115m depth.
‘.. we’re most likely picking up signals just at the edge of something much bigger.’
Litchfield Minerals Managing Director Matthew Pustahya
The hole went down further, pushing to termination at 174m depth, with visual logging also reporting intermittent traces of the same mineralisation between 139 and 160m depth.
The combination of the extensive mineralisation from the first VT1 drill hole and the strong DHEM sulphide response from up to seven closely-spaced conductors offers clear evidence of a fertile system immediately adjacent to the interpreted core of the main body.
The DHEM survey has resolved the true location of one of the conductors, and the existence of several interacting and/or structurally offset conductors.
It has also revealed a conductor strength and complexity far greater than was capable of being interpreted from the previous airborne versatile time domain VTEM survey.
VT1 continues to grow in size, strength and significance. Our geophysicists are confident we’re dealing with a very strong, multi-plate conductor system, one that’s considerably larger and more complex than what the airborne data initially suggested.
Litchfield Minerals Managing Director Matthew Pustahya
The company has also confirmed its first drill hole to probe VT1 tracked about 75m outside the targeted main conductive body, due primarily to the complexity of the multiple close-spaced conductors making precise targeting difficult, being based only on its initial VTEM results.
Additional contributing factors included problematic access for locating the drill pad in the rough terrain, which compelled selection of the best position possible to obtain an initial result from the most easily identified conductor.
Regardless of the near-miss, the first hole at VT1 has provided Litchfield with a good look at the geology and importantly, has also provided access for the follow-up DHEM survey, the results of which have appreciably changed the company’s understanding of the likely scale and extent of potential mineralisation that could be associated with the target.
The VT1 target lies about 5.4kms southwest of, and on the same arcuate mineralised trend as the company’s other priority VT2 VTEM target.
Both of those highly conductive VTEM targets lie on the opposite or eastern limb of the interpreted fold from the collection of outcrops that constitute the main Oonagalabi cluster on the western limb.
The VT1 target is more than 400m long, lies in an intensely folded geological corridor and has now been resolved by the latest DHEM survey as six and possibly seven distinct conductor plates.
In that respect, it differs from the VT2 target which the company has previously modelled as a single target approximately 500m long.
VT1’s geology is complex. And combined with the relatively limited resolution of the airborne VTEM geophysics, that means the target was always likely to require the closer proximity and greater precision of DHEM and other surface electromagnetic (EM) methods to model conductor shapes and geometry for improved targeting confidence.
The company says that when it deploys surface EM geophysics across the VT1 target, it anticipates a strong response that would be consistent with the combined responses from the DHEM survey and the 250m core diameter of the original airborne VTEM anomalism.
In view of the results, Litchfield has crafted a tailor-made high-resolution ground EM survey, slated to begin in the second half of the month to accurately capture the system’s geometry and intensity,
The survey will embrace tighter line spacing and higher station density to handle the anticipated strong conductivity and resolve multiple plates with precision. It will also include fixed-loop EM (FLEM) across the DHEM-defined area to provide tight spatial control, while maintaining efficiency and speed.
Litchfield says it believes the target specific design of the geophysical program will offer near-DHEM data resolution across the surface and allow the company to attack the target in its next round of drilling with greater confidence and precision.
Additional support is lent to the potential significance of the V1 target by geochemical resampling of the pulps from a previous surface rock chip sample taken from above VT1 where the company previously reported portable X-ray fluorescence (pXRF) results of 0.6 grams per tonne (g/t) gold, 0.6 per cent copper, 14g/t silver and 7g/t tellurium.
Highly anomalous platinum group element results were also recorded, including up to 0.1g/t palladium from gossanous rock outcrop, coincident with elevated nickel values of 850ppm nickel.
The company says that if a magmatic source is proven at VT1, an extensive system like Oonagalabi could harbour a potential Tier-1 deposit. Moreover, if the VT1’s palladium-nickel signature differs from that of mineralisation to the north, such as at VT2, it could reinforce the concept of zoned mineralisation across the Oonagalabi project.
The company now plans to carry out ground EM geophysics, beginning in about two weeks, followed by data integration and modelling to inform new drill target selection, with drilling expected to begin shortly afterwards to probe key elements of the new conductor models.
An important outcome of the work at VT1 to date is that Litchfield expects VT1 to become what it describes as one of the most significant and technically compelling targets within the broader Oonagalabi system.
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