Highlights

  • Constellation Resources shares surged 23.33% on 21 May 2026 following a major exploration update.
  • Surface gas sampling confirmed methane concentrations of up to 97%.
  • Helium readings reached up to 0.24% in samples collected from historic drillhole WHRD021.
  • The company received preferred applicant status for SPA-0143 in the Edmund-Collier Basin.
  • Historic drilling records also highlighted a combustible gas ignition event in 1977.
  • Ground exploration activities are targeted to commence during the second half of 2026.

Constellation Resources Ltd (ASX:CR1) shares surged 23.33% to AUD 0.18 during the afternoon session on 21 May 2026 after the company announced significant gas exploration results from its Edmund-Collier Basin project area in Western Australia. The stock has now climbed approximately 42.31% over the past year, with investors responding positively to the latest methane and helium findings alongside progress across newly awarded exploration acreage.

The market reaction followed confirmation that repeated gas sampling from a historic shallow drillhole returned exceptionally high methane concentrations alongside notable helium readings.

The update also included details surrounding the newly awarded SPA-0143 application area, which adjoins existing exploration holdings controlled by the company.

Constellation stated that recent analysis conducted in collaboration with Australia’s national science agency, CSIRO, reinforced the prospectivity for hydrogen, helium, methane and ethane across the broader project area.

Investor attention appeared to focus particularly on the scale of the methane concentrations reported, the ongoing venting observed from the historic drillhole and the broader implications for a potentially recharging basin-scale gas system.

Historic Drillhole Returns High Methane and Helium Readings

The centrepiece of the company’s announcement was historic drillhole WHRD021, originally drilled in 2012 as part of iron ore exploration activities.

The hole was later incorporated into CSIRO’s 2025 basin-wide natural hydrogen and associated gas research program after earlier studies identified elevated gas prospectivity.

Constellation reported that six downhole samples collected from the drill core during the CSIRO study returned the highest hydrogen, methane, helium and ethane readings across all drillholes analysed within the basin dataset.

The company then undertook additional field investigations after locating the historic drillhole collar during stakeholder engagement activities.

Over an eight-month period, repeated gas sampling from the collar of WHRD021 continued to return elevated methane readings.

According to the company, laboratory analysis of gas samples collected at the collar delivered methane concentrations of up to 97%, alongside helium concentrations reaching 0.24% on an air-corrected basis.

Constellation noted that methane concentrations above 85% are typically associated with Natural Gas pipelines, while helium concentrations above 0.1% are generally regarded as helium-rich.

Management described the discovery of such helium concentrations within a shallow mineral exploration hole as highly unusual and worthy of further exploration.

The company also highlighted that helium concentrations reported from the now-depleted Bayu-Undan gas field offshore Darwin ranged between 0.09% and 0.21% in individual wells.

Ongoing Gas Venting Suggests Potential Reservoir Connection

One aspect of the announcement that appeared to attract considerable market attention was the continued venting of gas from the historic drillhole collar.

Constellation stated that repeated field visits across eight months consistently detected elevated methane levels at the site.

The company indicated that the persistence of gas emissions may point toward a connection with an underlying reservoir rather than a limited trapped gas accumulation.

To collect the samples, the company used specialised gas capture methods designed to minimise atmospheric contamination and preserve the integrity of the readings.

The gas collection process involved sealing the drillhole collar to allow gases emanating from below the surface to accumulate before laboratory testing.

The company noted that additional work is still required to better understand both the source and composition of the venting gases.

Management also stated that the origin of the methane remains under investigation, with both biogenic and thermogenic pathways currently being assessed.

Possible methane generation mechanisms include microbial conversion processes involving hydrogen as well as geological heating processes linked to burial conditions.

Meanwhile, the helium may originate from radiogenic basement rocks or deeper mantle-related sources.

Historic 1977 Gas Ignition Event Adds Further Interest

In addition to the recent sampling results, Constellation also highlighted historic exploration records dating back to 1977.

A desktop review of historical drilling within SPA-0118 identified a percussion drillhole completed by AMOCO Minerals that reportedly intersected significant combustible gas volumes at around 300 metres depth.

According to the historical records, the gas outburst resulted in a surface ignition event during drilling operations.

While no compositional gas analysis was completed at the time, the ignition event confirmed the existence of combustible gas systems within the project area.

The company stated that the historic hole was drilled within a structurally favourable antiform extending more than 75 kilometres in an east-west direction.

Management believes the structural setting may represent an effective trapping mechanism similar to gas accumulations seen in other global basins.

The combination of historic gas shows, recent methane and helium readings and the presence of major structural traps appears to be reinforcing the company’s broader exploration thesis.

CSIRO Research Supports Basin-Wide Prospectivity

The latest exploration update also builds on broader technical work undertaken with CSIRO across the Edmund-Collier Basin.

According to the company, the basin contains geological ingredients considered favourable for hydrogen, helium and associated gas systems.

These include thick Proterozoic sedimentary sequences, organic-rich shales, carbonate units, deep fault systems and radiogenic basement rocks.

Constellation noted that the project area contains multiple potential trapping mechanisms for gas accumulation, including anticlines, structural traps, stratigraphic pinch-outs and hydrologic traps.

The basin’s geological evolution over more than one billion years may have supported long-term gas generation and accumulation processes.

The company’s broader project footprint now spans approximately 80,000 square kilometres across ten SPA and AO applications through its Subsidiary CR1 Energy.

The newly awarded SPA-0143 expands the company’s strategic landholding across the emerging natural hydrogen and associated gases sector in Western Australia.

Ground Activities Planned for Second Half of 2026

Constellation stated that ground exploration activities are targeted to commence during the second half of 2026.

The company has already secured all required native title approvals for SPA-0118 and SPA-0119, with final approvals for on-ground activity expected shortly.

Meanwhile, stakeholder engagement activities for SPA-0143 are set to continue as the company progresses toward further approvals.

Upcoming exploration work is expected to include soil gas surveys and additional drillhole collar gas sampling across multiple historic exploration holes.

The company also plans to undertake isotope analysis programs to better define the origin and composition of the gases encountered.

This work will include helium isotope testing to determine whether helium-3 associated with mantle processes may be present.

Further methane isotope analysis is also planned to assess whether the methane originates from microbial activity, geological heating processes or a combination of both.

Management believes sampling gas emissions from historic drillhole collars could become an important part of the broader exploration strategy across the basin.

Infrastructure Access Could Support Future Development

Another aspect highlighted in the announcement was the presence of existing gas infrastructure near the project area.

Constellation noted that the Goldfields Gas Pipeline traverses the region, potentially providing future infrastructure advantages should exploration activities continue successfully.

The proximity to existing transmission infrastructure may become increasingly relevant if further exploration confirms commercially significant gas accumulations.

At this stage, however, the company remains focused on early-stage exploration and technical evaluation activities.

What This Means for Investors

Constellation Resources’ latest announcement represents one of the more closely watched exploration updates among small-cap ASX resource companies this week.

The combination of exceptionally high methane readings, notable helium concentrations, ongoing gas venting and historical combustible gas intersections appears to have driven the sharp share price reaction.

Investors also appeared encouraged by the company’s growing strategic position across the Edmund-Collier Basin and the support provided by CSIRO’s broader technical assessment work.

While the project remains at an early exploration stage, the update reinforced the possibility of a large-scale gas system within a relatively underexplored region.

The market is likely to continue monitoring upcoming ground exploration activities, isotope testing results and further sampling work during the second half of 2026.

With the stock already delivering substantial gains over the past year, future exploration milestones may remain a key driver of investor sentiment toward Constellation Resources.