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Carbon Sequestration Potential

Magnesium rich ultramafic rocks are found throughout Aotearoa New Zealand. When exposed to CO2, these rocks chemically react and form new carbonate minerals, permanently binding the CO2 in the resulting rock.

This is a natural process called carbon mineralisation which can be accelerated using proven methods already adopted in Europe. We believe carbon mineralisation has the potential to play a pivotal role in Aotearoa NZ’s transition to a sustainable, net-zero-carbon future.

Weora Limited holds 8 Mineral Permits primarily focused on the magnesium-rich ultramafic rocks dunite and serpentinite which are highly reactive with CO2. Lab tests on the dunite within the permit areas show that they have the highest magnesium content out of all the ultramafic rocks in the world.

We are currently conducting our initial exploration programme at the Greenhills Igneous Complex near Bluff. The first two boreholes reached their target depths of 800 m and we are continuing to drill on the site. The rock samples from these boreholes have yielded very promising results, showing a continuous presence of magnesium-rich dunite from the surface to the end of the borings.

Rock samples from our permit areas have been sent to laboratories where they are being subjected to various mineral carbonation tests. The lab data combined with conventional exploration methods for reservoir definition, will allow us to identify suitable sites for trial in situ carbon mineralisation.

Natural Hydrogen

Ultramafic rocks produce natural hydrogen (H2) when metamorphosed in the presence of water, a process called serpentinisation. Although natural hydrogen exploration is still in its infancy, seeps are known to occur around the world, including in NZ. Natural hydrogen seeps have been recorded at Poison Bay, Red Hills and hydrogen was also encountered during driling at Weora’s Greenhills permit area.

It is unlikely that hydrogen will be found in pressurised stagnant reservoirs, as with traditional with methane deposits, instead, natural hydrogen occurs more often as slow flowing accumulations. Hydrogen gas is being continually generated from the serpentisation of the ultramafic rocks and it flows along the natural fractures within the rock mass.  We are investigating the economic potential for natural hydrogen across the licence portfolio’s and whether engineered systems for in situ carbon mineralisation could commercially produce hydrogen.

Strategy

Our Mineral Permits are strategically all located in close proximity to CO2 emission sources and contain large deposits of above ground and sub-surface ultramafic rocks, notably dunite.

Weora is actively engaging in discussions with nearby CO2 emitting industries operating near our permit sites. CO2 emission sources near the permit areas include smelters and power stations fired by coal and gas. We aim to explore the potential for capturing CO2 emissions at the source so that it can be sequestered through carbon mineralisation rather than released to the atmosphere.

We are also collaborating with researchers from multiple universities to explore the potential uses of the resultant carbonate rocks produced through ex situ mineral carbonation. This presents an exciting opportunity to replace existing products with alternative carbon-negative products, particularly in the construction sector.

The ultramafic rocks within the permit areas have the capacity to safely store carbon emissions for many centuries.

New Zealand Dunite

NZ’s Dunite rocks were first identified in 1859 by a German geologist at Dun Mountain in the Nelson District.  The mountain was a dun colour and largely devoid of vegetation due to its high magnesium and iron content. The rock type was subsequently named dunite and Aotearoa NZ has one of the world’s largest dunite deposits.

Naturally occurring mineral carbonation takes place where ultramafic rocks are exposed to atmospheric CO2 at the surface. This has been found to  occur at Greenhills and West Dome in Southland, Fiordland National Park, Red Hills, and the Dun Mountain complex.

This natural process can be accelerated by either injecting CO2 underground or by crushing the rocks to increase their surface area and exposing them to CO2.