Study reveals natural gas potential in Niassa's Maniamba basin

The eight million square kilometer Maniamba Basin in Niassa province could be a major source of natural gas, according to Moçambique Bio, which cites a study published in the South African Journal of Geology.

"The Permian to Triassic rock layers in the basin contain mature organic material capable of producing natural gas," the publication reads.

In the work led by Nelson Nhamutole, a PhD student at the University of the Witwatersrand, samples from four outcrops in the basin were analyzed.

The researchers deciphered the organic richness of different rock types, including shale, claystone, sandstone and siltstone.

Through Rock Eval Pyrolysis, a technique used worldwide for gas and oil research, it was possible to find "good to excellent" total organic carbon content in the rocks of the Maniamba Basin, a key indicator of the rock's potential to generate hydrocarbons.

"At the heart of this valuable potential energy is kerogen, the organic matter in rocks which, under the right thermal conditions, can be transformed into natural gas and oil," we read.

The study identified a mixed presence of kerogen types, predominantly Type III and IV, suggesting that the organic matter is mainly of terrestrial origin. This points to a landscape once lush with vegetation typical of the Gondwana ecosystem and now the source of potential gas reserves.

The path from organic-rich rock to conversion into hydrocarbons is a matter of maturation. "Our ability to infer that maturation stages were somehow influenced by igneous intrusions on the basis of a small sample size is really exciting!" exclaimed the lead researcher.

The research shows that the rocks in the basin are mature to super-mature, influenced mainly by tectonic activity and the proximity of igneous intrusions (formations that occur when magma below the Earth's surface cools and solidifies before reaching the surface). This level of maturity integrated with the analysis of the type of organic matter is indicative of the basin's capacity to generate gas rather than oil, a crucial insight for future exploration strategies. Drawing parallels between sites in the Karoo, the study links the properties of organic matter in the Maniamba Basin with those found elsewhere in the Karoo stretching from Mozambique to Tanzania, Zimbabwe, Zambia and South Africa. This not only highlights the basin's potential, but also links it to a broader geological narrative of Gondwana, the ancient supercontinent.

The discovery of the Maniamba Basin's potential is a significant step forward in energy exploration, but it is only the first step. The research highlights the need for further investigations to fully unlock the secrets of the basin. Advanced studies, employing a range of geochemical and geological analyses, are essential to chart the path to production potential.

At a time when Mozambique is on the brink of a new era in energy exploration, the study of the Maniamba Basin shows the power of international collaboration in discovering the Earth's hidden treasures.

For a world facing energy challenges, the basin could offer a glimmer of hope, a promise of a sustainable future powered by the very rocks beneath our feet. "Rock assessment data alone cannot fully tell us about potential sources of oil and gas, so we need to use other methods as well," says Nelson. "In my future research, I plan to combine several techniques, including studying the types of organic material in the rocks, examining pollen and spores, looking at chemical fossils and analyzing the elements present to learn more about the potential of the source rocks in the Maniamba Basin. In addition, discovering the age of the rock layers by observing when certain microfossils appear and disappear will be especially important."

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