The oldest parts of the continental crust generate between 0.36–2.273×1011 moles H2 per year through water-rock reactions and radiolysis [1]. Over geological timescales the natural hydrogen generated would supply society’s current oil-equivalent needs with clean energy for well over 100,000 years. Natural (gold) hydrogen is found in many locations globally [1], but until recently has not been the focus of resource exploration. We show how Helium, generated during radiolysis, provides a key reference for understanding:

1. Whether the hydrogen generated in the deep crust is preserved [1,2]? 2. How and at what rate hydrogen escapes from the continental crust [3,4]? 3. Where the migrating crustal hydrogen might be focussed and accessibly trapped (and not consumed chemically or biologically) [3,5].

These provide the key steps in addressing whether, and where, natural (gold) hydrogen might provide a viable and significant clean energy resource.

[1] B. Sherwood Lollar, T. C. Onstott, G. Lacrampe-Couloume & C. J. Ballentine. Nature (2014) 516, 397-382
[2] O. Warr, B Sherwood Lollar, J. Fellowes, C.N. Sutcliffe, J.M. McDermott, G. Holland*, J.C. Mabry, C.J. Ballentine. Geochimica et Cosmochimica Acta 222 (2018) 340-362
[3] A Cheng, B Sherwood Lollar, O Warr, G Ferguson, E Idiz, SOC Mundle, PH Barry, DJ Byrne, JC Mabry, CJ Ballentine, Earth and Planetary Science Letters 574, 117175
[4] D. Danabalan, J.G. Gluyas, C.G. Macpherson, T.H. Abraham-James, J.J. Bluett, P.H. Barry, & C.J. Ballentine. The Principles of Helium Exploration. Petroleum Geoscience (2021) in Press