Discrepancy between terrestrial Xenology and He-Ne systematics

129 I/( 244 Pu+ 238 U) ratio, thus a function of the timing of MORB mantle fractionation. He-Ne isotopes of MORB- and plume- related samples indicate that the former reserevoir is richer in radiogenic isotopes relative to primordial isotopes and we want to test if a similar situation arises in the case of xenon isotopes been established to reveal the difference between two reservoirs due to different degree of radiogenic contribution. Since plume component suffered less radiogenic component according to He-Ne isotopes, similar observation should be expected on xenon while it is not clear due to atmospheric contamination.