3D MT Survey Identifies Untested 2200N Anomaly with 1.1Moz Gold Equivalent Potential
Dateline Resources has identified multiple promising rare earth element targets at its Colosseum Gold-REE Project in California, highlighted by a standout geophysical anomaly suggesting a carbonatite-hosted system. The findings pave the way for a new phase of exploration including deep drilling and integrated geochemical analysis.
- 3D magnetotelluric survey reveals multiple rare earth element drilling targets
- Prominent 2200N resistivity anomaly interpreted as potential carbonatite intrusion
- Anomaly coincides with fenite dykes, indicating strong REE mineralization potential
- New gold targets also identified and under review
- Drill planning and parallel data validation underway
Exploration Breakthrough at Colosseum
Dateline Resources Limited (ASX, DTR) has announced compelling results from a recently completed 3D magnetotelluric (MT) geophysical survey at its 100% owned Colosseum Gold-REE Project in California. The survey has delineated several high-priority rare earth element (REE) targets, with a particularly striking resistivity anomaly on survey line 2200N that suggests the presence of a carbonatite intrusion, a geological setting known to host significant REE mineralization.
The 2200N Anomaly, A New Frontier
The standout 2200N anomaly is a laterally extensive, high-resistivity zone extending from deep underground to near surface, spatially aligned with outcropping fenite dykes. Fenite alteration is a classic indicator of carbonatite-related mineral systems, reinforcing the interpretation that this anomaly could represent a previously untested carbonatite intrusive complex. This is particularly significant given the proximity to the Mountain Pass mine, one of the world’s largest rare earth deposits, located just 10 kilometres south.
Importantly, the 2200N target area has never been drilled, marking it as a fresh and high-potential exploration frontier. Historically, exploration at Colosseum focused on gold, leaving the REE potential underexplored. The identification of this anomaly opens a new chapter for the project, with deep drilling planned to test the extent and grade of REE mineralization.
Comprehensive Survey and Data Integration
The MT survey, conducted in June 2025, involved 167 stations across 14 east-west lines, providing high-resolution subsurface resistivity data. The data was processed using Viridien Geophysics’ advanced 3D inversion software, producing a detailed resistivity model that distinguishes potential carbonatite bodies from surrounding geology. The geophysical signature of the 2200N anomaly aligns with gravity and magnetic data, consistent with known carbonatite-hosted REE systems.
Alongside REE targets, the survey also highlighted several new gold exploration targets. These conductive zones, possibly extensions of known breccia pipes or new structures, are currently under evaluation. Dateline expects to release further updates on gold potential shortly, following detailed analysis.
Next Steps, Drilling and Validation
Dateline is advancing drill planning to test the 2200N anomaly and other high-priority targets. Concurrently, an independent 3D inversion using the ModEM software is underway to validate the primary resistivity model, ensuring robustness before drilling commences. Final geochemical assay results from recent sampling are also imminent and will be integrated with geophysical data to refine target prioritization.
Stephen Baghdadi, Managing Director, expressed optimism about the findings, emphasizing the alignment of geophysical data with geological indicators and the potential for significant REE discoveries. The company’s methodical approach aims to build on these insights to unlock the full mineral potential of the Colosseum project.
Bottom Line?
Dateline’s geophysical breakthrough at Colosseum sets the stage for a pivotal drilling campaign that could redefine its rare earth and gold prospects.
Questions in the middle?
- Will the upcoming drilling confirm economically viable REE mineralization at the 2200N anomaly?
- How will the independent ModEM inversion results influence the current exploration model?
- What is the potential scale and grade of the newly identified gold targets from the MT survey?
