Open Ground - Orange, NSW
Updated: Jul 28
Orange North is an early-stage gold–silver–base-metal prospect over vacant ground in the Mullion Range, roughly 25–35 km north of Orange in central NSW. The ground sits in a narrow corridor between two held exploration licences, on the northern strike projection of the same Late Silurian volcaniclastic horizon that hosts the Lewis Ponds (historical 3.7 Mt polymetallic massive sulphide, non-JORC) and McPhillamys (multi-million-ounce gold, Regis Resources) systems to the south.
The case rests on a single, striking coincidence: one rock chip — sample 823123 — returned an anomaly for gold, silver, arsenic, antimony and lead all at once, an order of magnitude above every other sample in a 72-sample historical compilation. It sits on the fertile horizon, on open ground, and has never been followed up by anyone.
How big is it? Honestly, that's the point — nobody knows yet, because nobody has tested it. The prospect itself is a single untested anomaly, not a defined resource. What's quantified is the neighbourhood: the horizon it sits on has already produced a 3.7 Mt polymetallic system and a multi-Moz gold deposit within tens of kilometres. Orange North is a chance to test whether that same fertile horizon carries a mineralised occurrence at a point where the historical operators simply stopped looking.
Why am explorer should revisit it: the entry cost is low, the ground is vacant, and the single most anomalous sample in decades of district data has never had a follow-up traverse run across it. It's a cheap, fast, high-information first test on a proven horizon.
Exploration history
~1977 — Union Corporation (EL904 / EL989). Model/target: VHMS base metals (Pb-Zn-Cu). Objective: test a regional geochemical anomaly for a massive volcanogenic deposit. Work: stream-sediment and rock-chip geochemistry, petrology. Departure: concluded base-metal potential was "very low" and relinquished — but the report records the ground lay ~1 km stratigraphically below the mineralised volcanic/sediment contact, i.e. they tested the wrong level, not a barren belt.
1996–97 — Delta Gold / Tri Origin Australia (EL4797 / EL5030). Model/target: gold and polymetallic mineralisation on the Lewis Ponds horizon. Objective: reconnaissance rock-chip sampling along strike. Work: rock-chip traverses — this is the programme that collected sample 823123. Departure: 823123 was logged as the "southern limit of sampling"; follow-up and planned ground EM were directed north to the Day Dawn and Lookout Rock prospects, so the anomaly was recorded and left behind.
Kamilaroi-era work (R00024958). Model/target: base metals in gossanous horizons. Objective: follow up anomalous stream sediments and gossans. Work: stream-sediment and rock-chip sampling; identified Long Point gossan, Imperial Bushman workings, Day Dawn. Departure: attention focused on named gossans elsewhere on the contact rather than the Orange North corridor.
2012 — Oakland Resources (R00003278). Model/target: regional gold–base metals. Objective: regional sampling sweep. Work: regional geochemistry across the broader district. Departure: did not re-occupy or re-sample the 823123 site specifically.
(Period spans six operators, 1971–2012. Coordinates are pre-GDA in the earlier programmes, which is itself part of why the site was never precisely re-found.)
Why the grade is still available
In plain terms: it was found once, on the edge of a survey, and everyone who came after was looking somewhere else.
The anomaly was a single grab sample recorded as the "southern limit of sampling" — the operator hit it and stopped, rather than following it up.
Follow-up in that programme was deliberately directed north (Day Dawn / Lookout Rock), so the site was mapped and abandoned in the same season.
Union Corporation walked away because their licence sat ~1 km below the prospective contact — a stratigraphic near-miss, not a barren result.
The site was never gridded, never soil-sampled, never geophysically surveyed, and never drilled.
It sits on vacant ground in a corridor between two held ELs — so no current tenement holder has an obligation or incentive to test it.
The historical coordinates are pre-GDA, so even later regional programmes couldn't easily relocate the exact point.
Every one of those is a reason it was skipped — none of them is a reason it's barren.
The miss, precisely
The miss, precisely: the single most anomalous rock chip in fifty years of district data — coincident gold, silver, arsenic, antimony and lead on a proven mineralised horizon — was logged as the "southern limit of sampling" in 1997, left behind while the crew moved north, and has sat untested on vacant ground ever since.
Most significant grades
All values are from sample 823123 (Delta Gold, 1996–97; DIGS R00002592). This is a single surface grab, not a resource — the significance is in the coincidence of elements, not any one number.
Element | Result | Compilation context | Why it matters |
Gold (Au) | 0.157–0.167 g/t | Next-highest in 72 samples is 0.029 g/t; only 14/72 detect Au | ~6× the next sample and an order of magnitude above background — a genuine outlier, not noise |
Arsenic (As) | 362 ppm | Order of magnitude above the string | Classic distal pathfinder for epithermal/VHMS gold — points to a system, not a stray grain |
Antimony (Sb) | 9 ppm | Compilation maximum | Second pathfinder element; strengthens the epithermal/VHMS read |
Silver (Ag) | 4 g/t | Compilation maximum | Confirms a precious-metal, base-metal-rich character consistent with the Lewis Ponds style |
Lead (Pb) | 461 ppm | Highest in compilation (marginally above a 1977 Union Corp sample at 420 ppm) | Base-metal tenor consistent with the polymetallic horizon (treat with care — Pb can be nugget-affected in grabs) |
Barium (Ba) | 1,360–1,550 ppm | ~2.3× background | Possible baritic exhalative/alteration component — the weakest of the six, but part of the coincident suite |
The headline is the coincidence: six elements peaking together in one chip, on the right horizon, where every neighbouring sample is subdued.
Geological setting
Orange North lies on the eastern limb and northern nose of the Mullion Range Anticline, within a Late Silurian volcaniclastic sequence — the "quiescence horizon" that marks the volcanic/sediment contact. This is the same stratigraphic package that hosts Lewis Ponds and McPhillamys along strike to the south, which is what makes the horizon prospective rather than the single sample alone.
The favoured interpretation is that 823123 marks the oxidised surface expression of a mineralised occurrence on this horizon. Being straight about it, a single grab can't distinguish between three viable models: a stratabound VHMS/epithermal system (the regional analogue), a structurally-controlled oxidised vein (the adjacent Ophir goldfield is a documented orogenic-vein district), or an isolated float/nugget with no continuity. The good news is that the same cheap surface programme discriminates between all three — so the uncertainty is a reason to test, not a reason to pass.
Top three targets (Phase 1 work)
Relocate and re-sample the 823123 site. Convert the pre-GDA coordinates, confidently re-find the point to within ~25 m, and re-sample. Achieves: confirms the historical result is real and repeatable, and resolves the position — the gate on everything downstream.
Orientation sampling across strike and to the south. Run rock-chip and soil traverses across the horizon and along strike beyond the old "southern limit". Achieves: tests whether the anomaly has continuity (a system) or dies immediately (an isolated block) — the single most decisive, lowest-cost test.
Structural and lithological mapping of the host horizon. Map the contact, structure and alteration through the corridor. Achieves: establishes whether the control is a stratabound horizon or a discrete structure — which model applies, and therefore where any drilling would eventually go.
Together these three items turn a fifty-year-old grab sample into a properly tested target for a fraction of a drill budget, and either advance Orange North to drill-ready or cleanly retire it.
Closing statement:
Not a JORC-compliant statement; historical results reported from open-file sources and not verified by a Competent Person.
All data sourced from publicly available NSW DIGS open-file records and public ASX disclosures.
This article is general information only and not investment advice
Full technical synthesis, intercept overview, drill plan and source register available on request.
