Bomb Diggity: Gravity Survey Unveils Promising Copper-Zinc Targets at Oonagalabi Project
Litchfield Minerals Limited (ASX:LMS) has identified multiple significant gravity anomalies coincident with and adjacent to the Bomb Diggity magnetic anomaly at its Oonagalabi Project, potentially indicating a major structural feeder linked to copper-zinc mineralisation in the region.
Gravity Survey Reveals Critical New Exploration Targets
Litchfield Minerals has completed a detailed ground gravity survey at the Bomb Diggity prospect, covering 1.8km x 2.2km with 231 stations on a 200m x 100m grid. The Litchfield Minerals gravity survey results have revealed four substantial gravity anomalies exceeding +0.5mGal, with the most significant finding being the offset relationship between magnetic and gravity features.
"The offset between the magnetic high and the newly defined gravity high is particularly important," explained Managing Director Matthew Pustahya. "In many world-class mineral systems — such as IOCG and skarn deposits — the magnetic core represents the unaltered intrusive, while the denser, mineralised zones occur along structural corridors that are often just offset from the magnetic source."
This pattern of offset anomalies is a defining characteristic of Iron Oxide Copper Gold (IOCG) and skarn-style deposits, where mineralisation typically forms on the margins of intrusive systems rather than within them.
Understanding the Bomb Diggity Anomaly
The Bomb Diggity prospect lies approximately 1.5km northeast of the main outcropping mineralised zones at Oonagalabi. It's defined by a high-intensity, northeast-plunging, pipe-like magnetic anomaly that isn't exposed at surface.
The survey identified four distinct gravity anomalies labeled A through D:
| Anomaly | Location | Characteristics | Interpretation |
|---|---|---|---|
| A & B | Top of magnetic anomaly | Syncline geometry, densities >2.77 SG | Likely folded Oonagalabi Formation |
| C | SE flank of magnetic anomaly | Associated with small magnetic anomalies, core density >2.8 SG | Possible alteration/mineralisation zone |
| D | Above thrust plane | No associated magnetic anomaly, core density >2.8 SG | Potential mineralisation zone |
Three-dimensional inversion modelling was completed to define the subsurface geometry of these anomalies, revealing that anomalies A and B could represent a significant northeastern extension to the mineralised system.
What This Means for Copper-Zinc Exploration
The geological significance of these findings cannot be overstated. Specific gravity measurements from 34 representative hand samples indicate that the Bomb Diggity gravity anomalies exceed the densities of the main country rocks within the project and are close to the densities calculated for marble and some calc-silicate alteration within the Oonagalabi Formation.
This suggests that anomalies A and B may represent a +1km northeastern extension to the mineralised system, while anomalies C and D could indicate alteration or mineralisation immediately adjacent to the main magnetic anomaly—a pattern consistent with major IOCG deposits worldwide.
Understanding IOCG and Skarn Deposits
IOCG (Iron Oxide Copper Gold) deposits represent a significant class of mineral deposits characterised by:
- Iron oxide minerals (magnetite or hematite) as the principal host rock
- Enrichment in copper and gold, often with various other elements
- Formation through hydrothermal processes related to magmatic activity
- Distinctive geophysical signatures, including magnetic and gravity anomalies
Skarn deposits form when hydrothermal fluids from cooling intrusions interact with carbonate rocks, creating zones of intense alteration and mineralisation. Both deposit types commonly show a pattern where the main magnetic anomaly (representing the intrusion) is offset from the gravity anomaly (representing the denser mineralised zones).
The identification of these offset anomalies at Bomb Diggity significantly increases the prospectivity of the area and provides compelling drill-ready targets.
Project Scale and Next Steps
Exploration to date has identified mineralised Oonagalabi Formation over at least 2.3km of strike, potentially extending to 3.6km if Anomalies A and B represent Oonagalabi Formation. The first phase of RC drilling showed a strong correlation between disseminated sulphide mineralisation and IP chargeability anomalies.
Litchfield Minerals plans to:
- Fly a tenement-wide VTEM (Versatile Time Domain Electromagnetic) survey to identify conductors potentially related to semi-massive and massive sulphides
- Drill-test the Bomb Diggity gravity anomalies in Phase 2 drilling if coincident conductive anomalies are identified
Pustahya noted, "This target has moved from being a speculative large anomaly to a high priority target that requires follow-up and will likely be drilled after a VTEM survey is conducted."
Why Investors Should Follow Litchfield Minerals
Litchfield Minerals has positioned itself as an emerging player in the critical minerals sector with several compelling investment considerations:
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Strategic Focus on Critical Minerals: The company is targeting copper and other critical minerals essential for the global energy transition.
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Significant Scale Potential: The company is targeting copper and other critical minerals essential for the global energy transition.
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Technical Excellence: The company is employing sophisticated exploration techniques, including 3D inversion modelling and integrated geophysical interpretation, to identify high-potential targets.
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Clear Pathway to Discovery: With the upcoming VTEM survey and planned Phase 2 drilling, Litchfield has defined a clear pathway to further advance the project.
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Exploration in a Tier-1 Jurisdiction: Operating in the Northern Territory of Australia provides political stability and established mining infrastructure.
The identification of these gravity anomalies at Bomb Diggity has substantially increased the prospectivity of the Oonagalabi Project, transforming it from a speculative target to a high-priority drill-ready prospect. With a strategic focus on critical minerals in a favourable jurisdiction, Litchfield Minerals offers investors exposure to a technically sound exploration programme with significant discovery potential.
Want to Invest in This Emerging Critical Minerals Opportunity?
For investors seeking exposure to critical minerals essential for the energy transition, Litchfield Minerals presents a compelling opportunity with its promising Oonagalabi Project. The identification of significant gravity anomalies at Bomb Diggity, potentially indicating a major copper-zinc system, showcases the project's considerable upside potential. To learn more about Litchfield Minerals and stay updated on their exploration progress in this promising Tier-1 jurisdiction, visit www.litchfieldminerals.com.au today.
