Mantle Minerals (ASX:MTL) defines nine drill targets at Yule River following gravity survey

Mantle Minerals has advanced exploration at its Yule River Project in Western Australia, with recently completed gravity and passive seismic surveys delineating multiple drill-ready targets beneath transported cover, shifting the project from a conceptual greenfields position to a defined targeting stage.

Highlights

• High-resolution gravity and HVSR surveys completed across the Yule River Project
• Multiple discrete gravity anomalies identified, including non-magnetic targets
• 9 priority drill targets defined, spanning VHMS, orogenic gold and Ni-Cu-PGE styles
• Phase 1 drilling programme being planned, targeting high-priority anomalies
• Drilling targeted for Q2 2026, subject to approvals and access

The Yule River Project is located approximately 35 km west of Port Hedland within the Mallina Basin, where the Scholl Shear Zone and Yule River Shear Zone converge.

This geological setting is described as analogous to the region hosting De Grey Mining’s Hemi Gold Deposit.

Historical exploration by Western Mining Corporation between 1991 and 1993 included 14 reverse circulation drill holes targeting magnetic anomalies.

Drilling intersected serpentinised ultramafic, felsic volcanic and cherty units, with hole MDRC4 returning anomalous gold of 46 ppb Au alongside alteration consistent with VHMS feeder systems.

The current geophysical programme, conducted by Atlas Geophysics and integrated with historical aeromagnetic data by Core Geophysics, was designed to refine subsurface architecture and resolve ambiguity in magnetic anomalies.

The combined gravity and HVSR datasets mapped variations in cover thickness and bedrock topography, identifying channel-like depressions and circular features not visible in magnetic data.

Importantly, the surveys identified discrete gravity highs with no magnetic association, representing a new style of target interpreted as potential hematite-rich or non-magnetic sulphide bodies.

Three broader zones were defined, comprising a western circular feature with magnetic response, an eastern circular feature with a gravity high and no magnetic response, and a central residual gravity high referred to as the Gravity Ridge.

From this dataset, Mantle has defined 9 exploration targets, labelled YRG1 to YRG9, representing a range of mineralisation models.

Higher-priority targets including YRG1, YRG3, YRG5 and YRG6 are characterised by discrete gravity anomalies, several of which are non-magnetic and located within structurally favourable positions such as the Gravity Ridge or associated features.

These targets are considered prospective for VHMS, orogenic gold and magmatic Ni-Cu mineralisation styles.

The company noted that timelines remain subject to heritage survey scheduling and access agreement processes with the relevant Native Title party.

Non-Executive Director Robert Mosig said:

“The addition of this gravity data with our existing geophysical and geological information has significantly improved and disciplined our understanding of the Yule River system. The results now clearly define coherent targets with characteristics consistent of a mineralised feeder structure warranting drill testing. Importantly, Mantle has now advanced the Yule River Project from a largely conceptual greenfields opportunity to one supported by multiple, well-defined drill targets. Mantle’s integrated geophysical dataset provides a strong advantage in targeting within this covered terrain.”

The programme represents a transition to a more data-driven exploration phase, with integrated geophysics enabling targeting beneath cover where traditional magnetic methods may be insufficient.

In this context, the upcoming drilling campaign will provide the first direct test of these newly defined targets and determine whether the interpreted structures correspond to mineralised systems.