GreenTech Metals Reframes Munni Munni Potential with New Basal Contact Sulphide Targets

Basal Contact Emerges as High-Priority Exploration Frontier

GreenTech Metals Ltd (ASX:GRE) has unveiled a fresh exploration narrative for its Munni Munni PGE-Cu-Ni Project in Western Australia, following an independent geochemical review by Dr Scott Halley. The review identifies the basal contact of the ultramafic sequence as a compelling target zone, supported by discrete copper anomalies in soil geochemistry that point to prospective basal contact-associated magmatic sulphide mineralisation.

Dr Halley’s analysis reveals a copper depletion signature in the lower ultramafic cumulates, interpreted as evidence of early sulphide saturation. This process is critical in concentrating copper, nickel, and platinum group elements (PGE) into immiscible sulphide melts, a hallmark of high-grade deposits in layered mafic-ultramafic intrusions. The basal contact’s potential was previously underexplored, marking a strategic pivot for GreenTech’s exploration approach.

Geochemical Signatures Mirror World-Class Intrusions

The Munni Munni intrusion’s architecture, comprising a thick ultramafic lower section overlain by gabbroic rocks, bears strong resemblance to the renowned Bushveld Layered Intrusive Complex in South Africa. The Ferguson Lode, a known PGE-bearing reef at Munni Munni, sits just below the transition from ultramafic to gabbroic lithologies, analogous to the Merensky Reef horizon in the Bushveld complex.

Major and trace element systematics delineate fractional crystallisation processes within the intrusion, while a substantial copper anomaly measuring approximately 5km by 2km in the upper sequence correlates with elevated vanadium and titanium levels in magnetite-rich gabbroic rocks. This anomaly suggests disseminated magmatic copper sulphides, opening a new exploration front beyond the basal contact targets.

Upcoming Geophysical Survey and Drilling to Probe Targets

GreenTech plans to deploy a co-funded Fixed Loop Electromagnetic (FLEM) survey over the newly identified basal contact copper anomalies this month. The FLEM survey is tailored to detect deep, conductive sulphide bodies beneath the soil geochemical anomalies, aiming to refine drill targets ahead of a planned drilling campaign.

This initiative complements GreenTech’s broader drilling strategy, which includes an 8,300-metre program across Munni Munni and Whundo, as previously outlined. The integration of geochemical insights with geophysical data is expected to sharpen the focus on high-grade mineralisation zones, potentially enhancing the project’s resource profile.

Historical Data Validation Underpins Confidence

The review incorporates multielement geochemical data from recent drill core resampling, including historic hole MMD0099 drilled by Helix Resources. GreenTech’s resampling efforts validate earlier assays, lending credibility to the geochemical framework and exploration targets. While some soil geochemical data derive from legacy programs under prior joint ventures, GreenTech is actively verifying these results independently to ensure robustness.

Geology advisor Dr Kevin Frost emphasises the novelty of focusing on the basal contact, noting it was not a previous exploration priority. The combination of copper anomalies at the basal contact and magnetite-rich zones in the upper intrusion expands the potential footprint for mineralisation within the Munni Munni intrusive complex.