Hydrogen gas occurs in ten Kansas wells near the Mid-Continent rift system. Since 1982, two wells have yielded small amounts of gases containing an average of 29-37 mole % H2, the remainder being chiefly N2 with only traces of hydrocarbons. Isotopic compositions for hydrogen (δD = −740 to −836 ‰) imply near-ambient (about 10°C) equilibration temperatures for the gases, which are among the most deuterium-depleted in nature and resemble the H2-rich gases described from ophiolites in Oman. Isotopic values for the Kansas N2 differ slightly from those of the atmosphere, but not enough to rule out an atmospheric origin. Because they are low in CH4 and CO2, expected byproducts of biogenic activity, the gases are probably abiogenic in origin. The existence of such gases near a major rift system, containing mafic rocks, and not far from known kimberlites is consistent with an origin from reactions involving Fe+2 oxidation, for example during serpentinization. Because the gases may be associated with kimberlites and deep-seated rifting, mantle outgassing is possible, but such an origin would be difficult to reconcile with the low isotopic temperatures.

The H2 gases from Kansas (and elsewhere) seem to be too low in pressure to have commercial value. However, neither the Kansas gases nor those from other H2 occurrences have been adequately examined to assess their importance as potential resources.

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