Ernest Jones

​Geological environments associated with the generation of natural hydrogen include Precambrian crystalline shields, greenstone and ophiolite belts and crustal suture zones associated with plate tectonic collisions. The serpentinization of ultramafic/mafic rocks such as basalt and peridotite in those environments is a metamorphic process that is effective in generating natural hydrogen in the subsurface through the hydration of ferrous iron present in minerals such as olivine. The global distribution of those mafic hydrogen source rocks is a result of the differentiation of the crust and plate tectonic activity during Precambrian and Phanerozoic supercontinent and tectonic cycles. Understanding the evolution of those crustal events and their relationship to the distribution of mafic rocks in suture zones, greenstone belts and Precambrian crystalline shields provides a first order view of the locations for natural hydrogen resources. Analysis of supercontinent tectonic cycles from the Paleoproterozoic (1.6 Ga), Mesoproterozoic (1.2 Ga), Neoproterozoic (800 Ma) and Phanerozoic (200 Ma) and the resultant distribution of Precambrian crystalline shields and greenstone and ophiolite belts that contain iron-rich ultramafic/mafic rocks provides insights about distribution of hydrogen source rocks on modern continents. Greenstones and ophiolites consist of ultramafic/mafic rocks such as basalt, gabbro and peridotite while Precambrian crystalline shields have higher ultramafic/mafic composition than younger crust. These rock types are present in the subsurface and outcrops in Africa, Australia, North America, South America and SE Asia. Outcrops of suture zones and ophiolites in Malaysia indicate that conditions are favorable for the generation of natural hydrogen.Three major supercontinents have been identified in the last 2 Ga: 1) Pangea, forming at 300 Ma, 2) Rodina forming at 1.3 to 0.8 Ga and 3) Columbia forming at 1.8 to 1.5 Ga. Mantle convection forced their breakup resulting in the current distribution of the Precambrian crustal blocks and greenstone belts of interest as potential hydrogen source rocks. Tectonic events in SE Asia during the Permo-Trassic and Jurassic also resulted in regional suture zones and ophiolite belts with the potential for hydrogen generation. Analysis of geologic maps of Africa shows the presence of Archean and Proterozoic continental blocks in North Africa near Mali where natural hydrogen has been discovered and is being produced. These Birimian (2.5 Ga) ultramafic/mafic rocks form parts of the basement in the Taoudeni basin and are likely sources of natural hydrogen. Likewise, mafic rocks in South Australia associated with Proterozoic island arc convergence may be source rocks for natural hydrogen. Triassic-Jurassic ophiolites in SE Asia along the Bentong-Raub suture zone also have mineral compositions consistent with natural hydrogen source rocks.This study provides fresh insights into the global distribution of natural hydrogen source rocks and the potential for hydrogen generation via serpentinization of mafic greenstone and ophiolite belts and Precambrian continental crust.​