Constellation identifies strong thermogenic hydrogen potential at Yerrida Project
Constellation Resources Ltd (ASX:CR1) has identified strong indicators of natural hydrogen (NatH₂) generation potential at its Yerrida NatH₂ Project in Western Australia, marking another step forward in its emerging natural hydrogen exploration portfolio.
The company has received Total Organic Carbon (TOC) results from two organic-rich formations within the 18,000-square-kilometre project area, revealing highly elevated TOC values — a key marker for thermogenic hydrogen generation.
Elevated organic content points to hydrogen potential
Two publicly available diamond drillholes from the Geological Survey of Western Australia (GSWA) core library were sampled, returning average TOC values well above the 2% threshold typically considered “organic-rich”:
- THD1: 286 metres at 5.2% TOC (from five core samples) within the Johnson Cairn Formation; and
- 85KDD1: 215 metres at 5.0% TOC (from nine core samples) within the Maraloou Formation.
The results confirm that the Yerrida Basin hosts thick, organic-rich shales comparable to formations in the nearby Edmund–Collier Basin, where Constellation and CSIRO studies have previously verified the presence of hydrogen, helium and natural gas.
Next steps: Thermal maturity and gas studies
Constellation plans thermal-maturity analysis and fluid-inclusion studies to determine whether the Yerrida shales have reached the thermogenic hydrogen-generation window. Field reconnaissance has already revealed gases seeping from an open exploration drillhole, with preliminary measurements showing sustained methane emissions of up to 160 parts per million by volume (ppmV).
Two separate samples collected and analysed by ALS confirmed the persistence of the emissions, although further work is needed to determine whether the methane derives from the conversion of hydrogen or another source.
Constellation said:
The company is highly encouraged by these sustained methane emissions, although the origin of methane is yet to be determined,
“Early inspection of historical drillhole collars may greatly assist in optimising the proposed soil-gas sampling locations/programs, possibly significantly reducing the number of sample points.”
Expanding Western Australian hydrogen portfolio
The Yerrida Project is the second of Constellation’s Western Australian NatH₂ projects to demonstrate encouraging results, following earlier discoveries of hydrogen and helium at the company’s Edmund–Collier Project.
The Yerrida Basin’s geological setting also supports multiple hydrogen-generation pathways, including:
- Thermogenic alteration of organic-rich shales;
- Serpentinisation of ultramafic rocks within Archean greenstones; and
- Radiolysis of water in Archean granites, which could also yield helium.
The company noted that similar TOC values and widths were encountered across both basins, reinforcing the potential for thermogenic hydrogen generation across its portfolio.
Constellation’s NatH₂ holdings now span more than 87,600 square kilometres across three under-explored sedimentary basins — a scale the company says offers “a first-of-its-kind opportunity” to explore for natural hydrogen in Western Australia.
Path forward
Upcoming work programs will include thermal-maturity testing, gas-composition analysis and the design of soil-gas surveys to refine sampling locations.
Constellation believes ongoing collaboration with CSIRO and GSWA will accelerate understanding of the region’s hydrogen systems and help position Western Australia at the forefront of natural hydrogen exploration.
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Constellation identifies strong thermogenic hydrogen potential at Yerrida Project, source
