A new continental hydrogen play in Damara Belt (Namibia)

Area of Science:

• Geochemistry
• Economic Geology
• Petrology

Background:

• Serpentinization is the primary accepted source of continental natural hydrogen (H₂).
• Recent studies indicate Archean-Paleoproterozoic banded iron formations (BIFs) as a potential H₂ source.
• BIFs may offer more efficient H₂ generation due to higher iron content compared to mafic rocks.

Purpose of the Study:

• To investigate the association between H₂ emissions in the Waterberg Basin, Namibia, and underlying Neoproterozoic BIFs (Chuos Formation).
• To identify H₂-generating minerals within the Chuos Formation.
• To assess the impact of metamorphism on the hydrogen generation potential of BIFs.

Main Methods:

• Structural and mineralogical analysis of rock samples from the Waterberg Basin.
• Identification of key minerals involved in hydrogen production, such as magnetite, biotite, and siderite.
• Field observations to infer the presence of subsurface H₂ generating systems, traps, and reservoirs.

Main Results:

• Structural evidence links reported H₂ emissions to the Neoproterozoic Chuos Formation BIFs.
• Magnetite, a known H₂-generating mineral, is ubiquitous in the Chuos Formation, alongside biotite and siderite.
• Metamorphism does not appear to deplete the essential Fe²⁺ content required for H₂ generation.

Conclusions:

• The Chuos Formation BIFs are a significant geological setting for natural hydrogen production.
• The presence of H₂ seepages suggests an active, deep H₂-generating system within the Waterberg Basin.
• Field observations indicate the likely presence of geological traps and reservoirs for accumulated H₂.