Morton Deep

Geological setting and mineral system

Hastings Block, eastern New England Orogen: granitoid-related Cu–Pb–Zn–Ag–Au–Sn–W mineralisation in Permian Beechwood Formation limestone–mudstone above the inferred Cairncross Adamellite heat source (government classification: "granitoid-related deposit", Gilligan & Brownlow 1987, R00009339). The Median Anticline controls the architecture — the Greenbourne Creek Zone (GCZ) on the northern limb; the drilled Zone A (NP) and Zone B (HR/MC) clusters on the southern limb and hinge. The interpreted productive position, a black mudstone–limestone horizon projected at 320–380 m vertical beneath the GCZ, is a structural inference from intersections above 100 m vertical — no historical hole has reached it.

The grades — what the system has already demonstrated

Hero results with confirmation status (metric, from primary sources)
HR4: 2.20 % Cu, 15.30 % Zn, 1.71 % Pb over 0.30 m (90.07–90.37 m), within 18 mineralised intervals across a 103 m zone. (R00026353)	Independently confirmed by the GSNSW 1999 government core-library re-sampling, 28 years after the original assay.
MC1: 4.3–4.62 % Cu, 6.5–10.30 % Zn over 0.38 m, plus 150 g/t Ag and 0.60 g/t Au. (R00014466, R00008831)	1971 primary vs 1983 Aberfoyle re-assay — range disclosed; Ag-Au added by the independent 1983 re-assay. Re-assay of archived core is a Phase 1 action.
MC3: 1.52 m at 0.668 % Cu (31.39–32.92 m) and 1.09 m at 5,630 ppm Cu, 5,150 ppm Pb.	Reported by the GSNSW 1999 government programme itself — not operator data.
Bellangry rock chip: 4,300 ppm Ag with 6.40 % Cu — the highest Ag result in the Hastings Block dataset. (R00015668/70)	Never drilled; gold never assayed in any Bellangry sample.

Exploration history — ten operators, documented exits

Every campaign found mineralisation; every departure is documented as economic or model-driven
1967–69	EZ Co. of Australasia (EL64)	VMS / skarn	IP attributed to pyrite background; shallow model missed the target horizon. (R00028111)
1969–71	Hastings Exploration N.L. (EL167)	Skarn base metals	Economic judgement at 1971 metal prices (quoted at §4); no drilling below 310 m. (R00026353)
1978–79	Pennzoil / Duval	VMS	Area held adequately tested for near-surface massive sulphide; method unsuited to a deeper target. (R00013081)
1979–86	Billiton / Shell / CSR JV	Sn-W / skarn	1986 tin-price collapse; Sn in core uneconomic; relinquished. (R00015668/70)
1982	WMC / Key Resources	Volcanic-hosted base metals	No economic mineralisation at the separate Huntingdon target; relinquished. (R00014985)
1983–86	Nationwide / BHP	Polymetallic skarn	Exit on gold and tin outcomes under their model (quoted at §4); GCZ drilling recommendation never actioned. (R00014471)
1991	Homestake (Barrick)	IRG / epithermal Au	Uneconomic under their epithermal gold model; Bi–Au coincidence noted, not followed up. (R00001682)
2003–10	Platsearch NL	IRG / porphyry Cu-Au	Native Title delays; no field work completed; relinquished ~2010.

Why the grade is still available — in the operators’ own words

Wrong commodity, wrong model. BHP’s 1985 assessment records the exit drivers as gold and tin outcomes — "gold stream samples failed to locate any areas of potential interest" and tin in core at "decidedly uneconomic levels" (R00014471) — not the copper-zinc system, and copper price is not cited in the reasons for departure. The 1971 conclusion, verbatim from Chief Geologist Ian Gould’s covering letter: "the drilling programme successfully located sulphide-mineralised skarn rocks at depth. However intersections were narrow and discontinuous, and of generally low grade" (R00026353) — an economic judgement at 1971 metal prices on holes that never exceeded 310 m. BHP’s own petrology on the NP28 boiling fluid-inclusion system states it represents "an ideal situation for the precipitation of gold" (MRL16976, R00014470) — an observation their gold-model exit never reconciled.

The analytical gap. No historical suite assayed the discriminating pathfinders: a column audit of the public GSNSW database for the area (6,479 trace-element rows; 6,959 pathway samples) returns zero records for Bi, REE, U, Co or Te, and every gold result exists only in DIGS PDFs — a first-pass database query shows no Au signal here. Against that gap: four independent bismuth confirmations across 40 years (BHP SEM native Bi with tentatively identified "?hedleyite"; Homestake ICP 210 ppm; GSNSW occurrence mineralogy; the Stony Creek W-Mo-Bi model). The untested target. The discrete 11.3 % FE GCZ IP centre — formally recommended for drilling by Nationwide/BHP in 1986 — has never been diamond drilled; NP27–29 sat within the broader anomaly but missed the target horizon.

The miss, precisely: (i) each era tested a single commodity or model — VMS, skarn base metals at 1971 prices, near-surface massive sulphide, tin, gold, epithermal — and no operator ever tested the system as a system; the lens that unifies the observations post-dates every campaign. (ii) The discriminating elements were never assayed: the question was never asked, not answered wrongly. (iii) No hole was drilled below 310 m in a system class whose productive levels typically sit at 400–2,000 m — with the interpreted host horizon projected at 320–380 m, just beyond the deepest historical hole. (iv) The GCZ drilling recommendation lapsed with BHP’s option expiry — orphaned by a corporate exit, not tested and failed.

System scale and the 2026 price lens

Footprint, not tonnes: a 4.5 × 2 km IP system; the GCZ anomaly 2.8 km × 1 km (Ward 1983); an Ag-bearing occurrence cluster spanning ≥7 km × 11 km; a 103 m mineralised zone in HR4 that ends in mineralisation at 188 m; and no hole below 310 m in a system class whose deeper levels typically run 400–2,000 m. Model-class context per the synthesis (§5.4): historical replacement-body analogues for the conservative skarn case are 0.5–3 Mt at 1–3 % Cu-equivalent — the intrusion-related alternatives invite larger comparisons that the pathfinder test is designed to earn or eliminate. The price lens: copper was ~US$0.60/lb at BHP’s 1985–86 exit versus ~US$4.50–5.00/lb in 2026; on the conservative 1971 figures plus the 1983 Ag-Au additions, the MC1 interval carries an indicative combined metal value of ~US$700–1,000/t. Presented as the synthesis author’s commercial argument (§7.1.8) — context only, no recovery, mining or processing costs applied, and not attributed to any historical operator.

The targets

GCZ (primary): coincident IP–geology–structure; high chargeability with high resistivity, consistent with semi-massive replacement — with the known limitation stated plainly: frequency-domain IP also responds to disseminated pyrite, which is exactly what the Phase 2 time-domain EM is designed to resolve pre-drill. Zone B depth: HR4 ends in mineralised core; only the south-central part of a 600 × 150 m coincident soil anomaly tested at depth; nothing below ~100 m vertical on the horizon. Bellangry: highest-Ag surface result in the district, never drilled, Au never assayed. Koree & Brombin: two historical gold workings inside the licence, never modern-sampled.

 Testing the thesis — gates, kill criteria, cost to answer

Every failure mode is paired with a cheap, pre-specified test — validation before drilling capital
Phase 1 — A$28–52k	48-element ICP-MS with full REE on archived NP28/HR4 core (A$4.5–7.5k incl. QAQC; confirm/kill thresholds set before dispatch), MC1 re-assay resolving the 1971/1983 discrepancy, full-core pXRF of HR4, 3D geophysical reprocessing.	Gate A. Kill answer for "pathfinders absent" costs A$3–4k and is binary; a flat result re-frames to the conservative skarn case, not zero.
Phase 2 — A$27–58k	VTEM/SIROTEM over the GCZ — the definitive test of "the IP is disseminated pyrite background"; first modern sampling at Koree, Brombin, Red Bank and Bellangry (first-ever Au assay at Bellangry).	Gate B. Discrete conductor → drill committed; none → GCZ hole deferred, Zone B depth hole promoted.
Phase 3 — designed drilling	MD-P3-01: 480 m NQ2 parametric hole through the GCZ discrete centre and projected horizon (≈A$210k central). MD-P3-02 (contingent): 280 m undercut of the MC1 section at 180–220 m vertical (≈A$105k). Oriented core, full QAQC, downhole survey; CMEP co-funding candidate for up to 50 % of direct drilling costs.	Post-hole review against pre-stated kill criteria; a barren-but-altered intersection with a coherent pathfinder vector is a continuation result, not a kill.

 Technical Manager: Dr Tim McConachy FAusIMM (1974), Senior Fellow SEG, former Rio Tinto Chief Geologist.

Data room (under NDA): technical synthesis v4.1, Phase 1 drill programme design, source register and figure set.

Contact: Doug Alcock, Managing Director, CAADIA Metals Pty Ltd — dalcock@caadiametals.com.au

No JORC (2012) Mineral Resource, Ore Reserve or Exploration Target is declared or implied. Historical results are compiled from GSNSW open-file (DIGS) records, have not been verified by a Competent Person for public reporting, and are provided for context only. The IRGS / distal-replacement interpretation is a working hypothesis under test; alternative interpretations of the geophysical data exist. Earn-in terms are indicative and non-binding, subject to contract, due diligence and grant of the Exploration Licence.